A new study from <a href="https://www.osu.edu/">Ohio State University</a> reveals what is going on inside of your <a href="https://www.earth.com/news/gut-brain-interactions-have-an-influence-on-diseases/">brain</a> when you get lost in a fictional fantasy. The experts discovered that the more immersed we become in the lives of our favorite characters of fiction, the more our brain activity reflects how much we identify with them.
&#8220;When they think about a favorite fictional character, it appears similar in one part of the brain as when they are thinking about themselves,&#8221; said study lead author Timothy Broom.
The research was focused on self-described fans of the HBO series &#8220;Game of Thrones.&#8221; The individuals were instructed to think about themselves, nine of their friends, and nine characters from the drama series. The participants also reported on which character they felt closest to and liked the most.
According to Broom, Game of Thrones was ideal for this study because it attracted a devoted fan base and the large cast presented a variety of characters that people could become attached to.
One of the key findings involved participants who scored highest on &#8220;trait identification.&#8221; These individuals agreed most strongly with statements like &#8220;I really get involved in the feelings of the characters in a novel.&#8221;
&#8220;People who are high in trait identification not only get absorbed into a story, they also are really absorbed into a particular character,&#8221; said Broom. &#8220;They report matching the thoughts of the character, they are thinking what the character is thinking, they are feeling what the character is feeling. They are inhabiting the role of that character.&#8221;
The researchers used an fMRI machine to measure activity in various parts of the brain through small changes in blood flow. As the participants&#8217; brains were scanned, they were evaluating themselves, their friends, and Game of Thrones characters. 
A part of the brain called the ventral medial prefrontal cortex (vMPFC) is known to show increased activity when people think about themselves and, to a lesser extent, when they think about close friends.
While in the fMRI, the individuals were shown a series of names &#8211; including themselves, friends, or characters &#8211; along with a trait, such as lonely, sad, trustworthy, or smart. The participants simply said &#8220;yes&#8221; or &#8220;no&#8221; to imply whether the trait fit the person.
As expected, the vMPFC was most active when people were evaluating themselves, less active when they evaluated friends, and least active when they evaluated characters from Game of Thrones.
However, among those who were high in trait identification, the vMPFC was more active when they thought about the fictional characters than it was for participants who identified less with the characters. This region of the brain was particularly active when the individuals evaluated the character they identified with the most.
Study co-author Dylan Wanger said the findings help explain how fiction can have such a big impact on some people.
&#8220;For some people, fiction is a chance to take on new identities, to see worlds though others&#8217; eyes and return from those experiences changed,&#8221; said Wagner.
&#8220;What previous studies have found is that when people experience stories as if they were one of the characters, a connection is made with that character, and the character becomes intwined with the self. In our study, we see evidence of that in their brains.&#8221;
The study is published in the journal <a href="https://academic.oup.com/scan">Social Cognitive and Affective Neuroscience</a>.
&#8211;&#8212;
By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

What happens in your brain while you're lost in fiction

Protecting 30 percent of land and <a href="https://www.earth.com/news/ocean-heat-reached-a-record-high-for-the-sixth-straight-year/">sea</a> by 2030 is an important benchmark, but it will not be enough to halt and reverse biodiversity loss, according to a team of more than 50 scientists from 23 countries. 



The experts delivered a synthesis of the science supporting 21 targets in a draft of the <a href="https://www.cbd.int/article/draft-1-global-biodiversity-framework">Post-2020 Biodiversity Framework</a>, a plan being negotiated by the United Nations.



The scientists are calling for systematic changes, including substantial reductions in damaging fisheries and farming subsidies, great reductions in overconsumption, and limiting global warming to 1.5°C.&nbsp;



Paul Leadley, a professor at Paris-Saclay University, is also an assessment leader and past chair of <a href="http://www.biodiscovery.com/">BioDISCOVERY</a>.



“The target of protecting 30% of all land and seas is important and attracting a lot of attention. And expanding protected areas is a good start if done well, but far short of what's needed to halt and reverse biodiversity loss - called ‘bending the curve’ for biodiversity."



"There’s very good evidence that we will fail again to meet ambitious international biodiversity objectives if there’s too much focus on protected areas at the expense of other urgent actions addressing the threats to biodiversity.”&nbsp;



“Governments are clearly struggling with the breadth and depth of the ‘transformative changes’ needed to bend the curve for biodiversity, and sometimes seem unwilling to face up to it.&nbsp; But deep changes are necessary and will greatly benefit people in the long run.”



The key points highlighted in the study were that reversing biodiversity loss requires transformative change, coordinated at every level. Along with these changes, assessments must be carried out and greater monitoring efforts funded. Perhaps most importantly, action must be taken immediately to be impactful.&nbsp;



“The sooner we act the better. Time lags between action and positive outcomes for biodiversity can take decades so we must act immediately and sustain our efforts if we are to reach the global goals by 2050," said study co-author Maria Cecilia Londoño Murcia of the Humboldt Institute.



"The time needed for safeguarding and restoring ecosystem structure, function and resilience is particularly critical for people and communities whose livelihoods and well-being directly depend on these systems and the benefits they provide.”&nbsp;



---By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Sweeping changes needed to reverse biodiversity loss

Protecting 30 percent of land and sea by 2030 is...

One of the most striking discoveries in Astrophysics over the past decades is that <a href="https://www.earth.com/news/dozens-of-free-floating-planets-found-in-the-milky-way/">planets</a> or satellites with oceans beneath layers of rock or ice are quite common in our solar system. Some major examples of these “interior water ocean worlds” (IWOWs) are the icy satellites of giant planets, such as Europa, Enceladus, or Titan, or distant planets like Pluto.&nbsp;



Mimas is the small, innermost moon of Saturn, which was previously thought to be a frozen, inert satellite. By identifying a curious libration, or oscillation, in the rotation of Mimas, a research team led by the Southwest Research Institute (SwRI) has discovered that this satellite is in fact an IWOW. The experts found a liquid, internal ocean hidden under a thick icy shell.



“Because the surface of Mimas is heavily cratered, we thought it was just a frozen block of ice,” said study lead author Alyssa Rose Rhoden, an expert in the Geophysics of icy satellites at SwRI. “IWOWs, such as Enceladus and Europa, tend to be fractured and show other signs of geologic activity.”&nbsp;



“Turns out, Mimas’ surface was tricking us, and our new understanding has greatly expanded the definition of a potentially habitable world in our solar system and beyond. If Mimas has an ocean, it represents a new class of small, ‘stealth’ ocean worlds with surfaces that do not betray the ocean’s existence.”



According to the scientists, tidal heating within this satellite must be large enough to keep the ocean from freezing, but small enough to maintain a thick, steady-state ice shell covering it. Further research is needed to shed more light on the complex factors leading to this peculiar equilibrium on Mimas, and to clearly understand how its ocean formed and evolved.



“Although our results support a present-day ocean within Mimas, it is challenging to reconcile the moon’s orbital and geologic characteristics with our current understanding of its thermal-orbital evolution,” Rhoden said.&nbsp;



“Evaluating Mimas’ status as an ocean moon would benchmark models of its formation and evolution. This would help us better understand Saturn’s rings and mid-sized moons as well as the prevalence of potentially habitable ocean moons, particularly at Uranus. Mimas is a compelling target for continued investigation,” she concluded.



The study is published in the journal <a href="https://www.sciencedirect.com/science/article/abs/pii/S0019103521005091?via%3Dihub">Icarus</a>.



---



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

"Stealth” ocean discovered on one of Saturn’s moons

One of the most striking discoveries in Astrophysics over the...

Insects don’t have noses and are not able to “smell” the roses in the familiar sense of the word. Instead, most odor molecules are detected by chemoreceptors that occur on an insect’s antennae. Using these chemical receptors, insects are capable of perceiving and differentiating between thousands of&nbsp;airborne compounds. They use these chemical signals to locate forage <a href="https://www.earth.com/news/some-plants-wont-survive-the-loss-of-seed-dispersing-animals/">plants</a> and mates, as well as to avoid predators.



But now, new research indicates that common air pollutants present in rural and urban environments may be hampering the ability of insects to detect the chemical signals so crucial to their activity as pollinators.&nbsp;



A team of scientists from the <a href="http://www.reading.ac.uk/">University of Reading</a> has conducted the first study to observe that common air pollutants, including diesel exhaust fumes and ozone, have a negative impact on the success of pollination by insects.&nbsp;



“We knew from our previous lab studies that diesel exhaust can have negative effects on insect pollinators, but the impacts we found in the field were much more dramatic than we had expected," said Dr. Robbie Girling, who led the project.



These previous laboratory studies by members of the Reading team showed that&nbsp;chemicals in <a href="https://www.reading.ac.uk/news-archive/press-releases/pr649662.html">diesel fumes react with and can change the scents of flowers such that the insects cannot locate the flowers. </a>The research suggested that pollution could contribute to the ongoing declines in pollinating insects, by making it harder for them to locate the pollen and nectar that form their food.



In the new study, the researchers aimed to gather evidence showing how air pollution affects different species of pollinating insects, some of which rely on scent more heavily than others.



The study, funded by the Natural Environment Research Council, used a purpose-built fumigation facility to regulate levels of nitrogen oxides (NOx) – present in diesel exhaust fumes – and ozone in an open field environment. They then observed the effects these pollutants had on the pollination of black mustard plants by free-flying, locally-occurring pollinating insects over the course of two summer field seasons.



Although the experiments made use of pollution levels that were way below the maximum acceptable levels considered as safe in the US, the results of the field experiments were dramatic. The researchers observed 62 to 70 percent fewer pollinator visits to the plants located in polluted air. This reduction was seen in seven different groups of pollinators, including bees, moths, hoverflies and butterflies.&nbsp;



There were also 83 to 90 percent fewer visits to flowers by these insects, and ultimately a 14 to 31 percent reduction in pollination success, based on the measurement of seed yield and other factors.



“The findings are worrying because these pollutants are commonly found in the air many of us breathe every day," said Dr. James Ryalls. "We know that these pollutants are bad for our health, and the significant reductions we saw in pollinator numbers and activity shows that there are also clear implications for the natural ecosystems we depend on.”



Insects are important pollinators of crops upon which we depend for food and so a reduction in pollinating activity could have far-reaching economic and social consequences. Around 70 percent of crop species rely on insects for pollination; these include apples, strawberries and cocoa.&nbsp;



In addition, pollination supports around eight percent of the total value of agricultural food production, worldwide. The pollinating activity of insects thus generates hundreds of billions of pounds worth of economic value each year.&nbsp;



Furthermore, far higher levels of air pollutants are found in many areas around the world where people and businesses breach the regulations. For example, a&nbsp;<a href="https://www.independent.co.uk/climate-change/news/air-pollution-england-defra-labour-who-nitrogen-dioxide-luke-pollard-b404484.html?r=55147">2019 analysis</a> recorded illegal levels of nitrogen dioxide present in local authorities, in large areas of northern England (including Cheshire and Gateshead), and in southern England (including Wiltshire, Chichester and rural areas such as the New Forest).



“This truly cross-disciplinary work demonstrated very clearly how atmospheric pollutants negatively impact on pollination with direct consequences for food production as well as the resilience of our natural environment," concluded study co-author Dr. Christian Pfrang.



Their results are published today in the <a href="https://doi.org/10.1016/j.envpol.2022.118847">&nbsp;journal&nbsp;</a><a href="https://www.journals.elsevier.com/environmental-pollution">Environmental Pollution</a>.



---



By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Air pollutants confuse pollinators and reduce food production

Insects don’t have noses and are not able to “smell”...

In a new study from <a href="https://wsu.edu/">Washington State University</a> (WSU), experts have found that a high protein diet increases the risk of kidney <a href="https://www.earth.com/news/coffee-stimulates-digestion-and-protects-against-disease/">disease</a> and premature death among captive polar bears. 



Previous studies have suggested that there is a similar link between kidney disease and excessive protein consumption among humans. The Mayo Clinic reports that a high-protein diet may worsen kidney function in humans, particularly in the long term, because the body may struggle to eliminate all the waste products.



A research team led by WSU wildlife biologist Charlie Robbins investigated what zoos have typically been feeding polar bears. The study revealed that their diet usually consists of a food ratio intended for big cats, containing about two to three parts protein to one part fat. This diet is the opposite of what polar bears would be eating in the wild.&nbsp;



“Zoos made some assumptions in the past about the nutritional requirements of polar bears because their diet is almost exclusively animals,” said Professor Robbins. “But, unlike cats, they do not need and cannot tolerate high protein.”



Even though polar bears are carnivores that feed mainly on seals, researchers have found that they have physiology that is more closely aligned with humans and other omnivores.



Looking at death records of captive polar bears, the researchers discovered that the most common cause of death was kidney disease. Bears with fatal kidney disease died 10 years earlier than bears without the condition. The second most common causes of death were liver disease and cancer, according to the analysis.&nbsp;&nbsp;



Out of more than 600 bears examined in the wild, the team found no evidence kidney disease.



“A slate of early deaths across sexes that is limited to two major organs raised several red flags for us,” said Professor Robbins, who has researched both grizzly and polar bear nutrition for more than 35 years.



Former WSU graduate student Karyn Rode conducted field studies which showed that wild polar bears prefer a diet that is two parts fat to one part protein.



“Although we knew that polar bears selected for the blubber of their prey, this was the first time we were able to quantify how much fat they were actually consuming,” said Professor Robbins. “When it comes to feeding polar bears, the general mindset has been that they are carnivores. No one has really been paying attention to the amount of protein they might need, much less limitations on how much they might tolerate.”



In the current paper, the researchers propose that - like humans - both polar and grizzly bears require relatively low levels of protein. When captive bears were offered their choice of blocks made up of pure lard and blocks made up of high protein meat, they ultimately consumed the same ratio of fat to protein as their relatives in the wild.



The study authors recommend that zoos should adopt alternative foods for captive polar bears that mimic the fat-protein ratio found naturally in the wild. Once these alternatives are introduced, monitoring the animals could help experts determine whether the new diets may improve their health and longevity.



The study is published in the journal <a href="https://onlinelibrary.wiley.com/journal/10982361">Zoo Biology</a>.



---



By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

High protein diet causes kidney disease in polar bears

In a new study from Washington State University (WSU), experts...

There are a few species of beetles that can jump, but beetle larvae tend to squirm across the substratum and have never been seen doing acrobatic jumps -- until now.



A team of researchers has published a scientific article documenting the jumping behavior of larval lined flat bark beetles (Laemophloeus biguttatus). This type of <a href="https://www.earth.com/news/animal-locomotion-natural-energy/">locomotion</a> has not been recorded for beetle larvae before. 



The larvae are able to spring into the air with a speed of around 0.5 meters per second, and to travel forwards a distance approximately equivalent to four times their own body length. While flying through the air, the larva curls itself into a loop and as it lands, it bounces and rolls along until it becomes stationary.&nbsp;



“Jumping at all is exceedingly rare in the larvae of beetle species, and the mechanism they use to execute their leaps is – as far as we can tell – previously unrecorded in any insect larvae,” said study co-author Matt Bertone, director of <a href="https://www.ncsu.edu/">North Carolina State University</a>’s Plant Disease and Insect Clinic.&nbsp;



“The way these larvae were jumping was impressive at first, but we didn’t immediately understand how unique it was,” said Bertone. “We then shared it with a number of beetle experts around the country, and none of them had seen the jumping behavior before. That’s when we realized we needed to take a closer look at just how the larvae was doing what it was doing.”



Usually when insects make impressive jumps, they rely on a “latch-mediated spring actuation mechanism.” This means that two parts of the body latch onto each other while the insect exerts force using its muscles. When this builds up a significant amount of potential energy, the insect unlatches the two parts and all the stored energy is released at once. This results in an action-packed spring off the ground.



The researchers looked for a two-part latch mechanism on the surface of the lined flat bark beetle larvae and found nothing. Then, they used microCT scans to measure how much muscle the beetle larvae had and calculated whether this would provide enough power to launch the larvae into the air at a speed of 0.5 meters per second. The larvae did not have enough muscle to achieve this by muscle action alone.&nbsp;



The conclusion was that the larvae must be using some form of spring-loaded system to achieve their acrobatic jumps. This is when Bertone and study co-author Adrian Smith decided to film the behavior in order to get a better understanding of what was taking place. Smith is a research assistant professor of biological sciences at NC State and head of the Evolutionary Biology &amp; Behavior Research Lab at the North Carolina Museum of Natural Sciences.



The team filmed some jumps at 60,000 frames per second and were able to see that the beetle larvae actually hook their feet into the ground as they arch their bodies and prepare to jump. As soon as one foot loses its grip on the ground, the spring is released and the larva is propelled into the air under the power of its body’s own potential energy store.



“What makes the&nbsp;L. biguttatus&nbsp;so remarkable is that it makes these leaps without latching two parts of its body together,” said Bertone. “Instead, it uses claws on its legs to grip the ground while it builds up that potential energy – and once those claws release their hold on the ground, that potential energy is converted into kinetic energy, launching it skyward.”



Meanwhile, in&nbsp;<a href="https://www.youtube.com/watch?v=SEst5RERHJ4">an unrelated video about jumping maggots</a>, Smith had included a short clip of the jumping behavior in&nbsp;L. biguttatus. That video was seen by Takahiro Yoshida, a researcher from Tokyo Metropolitan University in Japan, who had witnessed similar jumps in the larvae of another beetle species called&nbsp;Placonotus testaceus, but had not published anything related to the behavior. Yoshida is a co-author on the publication about this unusual form of locomotion.



“We don’t have high-speed footage of&nbsp;P. testaceus, but the video evidence we do have from Yoshida’s lab suggests that this previously unknown behavior is found in two different genera which are not even closely related,” said Bertone.



“This raises a lot of questions. Has this behavior evolved separately? Is it found in other beetle species? Are these genera more closely related than we previously suspected? There’s a lot of interesting work to be done here.”



Details of this unusual method of locomotion in lined flat bark beetle larvae are published today in the journal <a href="https://journals.plos.org/plosone/">PLOS ONE</a>.



---



By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Unusual jumping behavior recorded in beetle larvae

There are a few species of beetles that can jump,...

A new study from the <a href="https://www.ubc.ca/">University of British Columbia</a> has revealed that 45 percent of the fish that cross through two or more exclusive economic zones (EEZs) will shift their movement patterns by 2100. This is expected to possibly bring international conflict.&nbsp;



By 2030, 23 percent of these fish are predicted to change their historic ranges. By 2100, this increases to 45 percent of the transnational fish, along with 81 percent of EEZs seeing at least one species shift. The culprit for these changes is, of course, human-caused climate change.&nbsp;&nbsp;&nbsp;&nbsp;



“This is not only an issue of stocks leaving or arriving to new EEZs, but of stocks that are shared between countries, completely changing their dynamics,” said study lead author Dr. Juliano Palacios-Abrantes, who conducted the study while at UBC’s Institute for the Oceans and Fisheries (IOF).&nbsp;



“We will see even more dramatic changes by 2030 and onwards, given current emissions rates. Many of the fisheries management agreements made to regulate shared stocks were established in past decades, with rules that apply to a world situation that is not the same as today.”



The researchers tracked the changing ranges of 9,132 transnational fish populations, which account for 80 percent of the catch from the world's exclusive economic zones. The research started in 2006 and continued forward with projections predicted up to 2100.&nbsp;&nbsp;



“By providing estimates of the size and timing of projected shifts, our study offers tangible reference points around which to consider climate change impacts and negotiate fair policies for sustainable management” said study co-author Dr. Colette Wabnitz, lead scientist at Stanford’s Center for Ocean Solutions.



“We must accept that climate change is happening, and then move fast enough to adapt fisheries management regulations to account for it,” said co-author Dr. Gabriel Reygondeau, a research associate at IOF.



The scientists hope their study can create a framework for international negotiations and planning to create a well designed fisheries management plan for the future. Without this, conflict, even violent conflict could arise over dwindling fish populations supporting a hungry human populace.&nbsp;



The study is published in the journal <a href="https://onlinelibrary.wiley.com/journal/13652486">Global Change Biology</a>.&nbsp;



---



By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nearly half of the world’s shared fish are on the move

A new study from the University of British Columbia has...

A new study from the <a href="https://www.ubc.ca/">University of British Columbia</a> has taken a closer look at the ultraviolet "bullseye" patterns found on sunflowers. The ultraviolet (UV) <a href="https://www.earth.com/news/dragonfly-wing-colors-driven-by-climate-and-sexual-selection/">colors</a> are invisible to humans, yet clearly visible to many insects.&nbsp;



The bullseye patterns were already known to make the flowers more attractive to bees, but scientists have now discovered that they do much more. The researchers found that chemicals in the UV markers also help the plants respond to stress from drought and extreme temperatures.&nbsp;&nbsp;&nbsp;&nbsp;



“Unexpectedly, we noticed that sunflowers growing in drier climates had flowers with larger UV bullseyes, and found that those flowers are able to retain water more efficiently. This suggests that these larger UV bullseyes help plants adapt to these drier environments,” said study lead author Dr. Marco Todesco, a research associate in the UBC Department of Botany.



Dr. Todesco and colleagues grew nearly 2,000 individual sunflowers of two different species in a lab in 2016 and 2019. Measuring the UV patterns and examining the genome of the plants, the researchers found that sunflowers growing in different regions of North America had differently sized bullseye patterns. Bees were better able to see the larger bullseyes.&nbsp;



The experts also found that the same gene that controlled the bullseye pattern was used in the production of UV-absorbant flavonoids, which help the plants survive stresses from things like drought and high temperatures.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;



“Floral UV patterns appear therefore to play at least a dual role in adaptation; besides their well-known effect on enhancing pollination, they also regulate water loss from flowers,” said study senior author Dr. Loren Rieseberg. “That’s not something you would necessarily expect a flower color to do, and it exemplifies the complexity and efficiency of adaptation - solving two problems with a single trait.”



The scientists feel more research into this adaptation could help improve the resilience of sunflower crops in the future.&nbsp;



The research is published in the journal <a href="https://elifesciences.org/">eLife</a>.



---



By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

"Invisible" colors in sunflowers do more than just attract bees

The story goes that, in 1820, a farmworker in the fields around Debenham in Suffolk, spotted a spectacular ear of barley. John Andrews picked the ear and planted the seeds at home in his <a href="https://www.earth.com/news/urban-gardens-provide-a-reliable-food-supply-for-pollinators/">garden</a>. When his landlord, Charles Chevalier, saw the remarkable barley that grew from these seeds, he was impressed and wished to grow more of it. He harvested it and began to propagate more plants, calling the new variety “Chevalier.”



At the time, barley was very important in the malting process used in the brewing of beer and very soon the new variety was being grown widely. In fact, by the end of the 19th century more than 80% of all malting barley in England was of the Chevalier type. The properties of this variety were considered so superior that the name Chevalier became synonymous with malting barley.&nbsp;



The variety became popular around the world, including in Sweden, where it was cultivated and improved, using breeding techniques, during the second half of the 19th century.&nbsp; Today, Chevalier is part of the lineage of many modern malting barley varieties and beer brewers have begun to consider returning to the use of this type, as well as other classic varieties of barley.



This has led Swedish researchers from the universities of Linköping and Stockholm to investigate whether the Chevalier variety of barley did indeed originate from a single plant, as described anecdotally. They wished to clarify how this cultivar was spread and adopted to Nordic seed systems of the time, and used molecular genetic analysis to establish whether the early Chevalier variety was used for selective breeding purposes to produce today’s varieties of malting barley.



“When we started this study, we were primarily curious about whether Chevalier barley had been discovered and used in the same way as today’s modern varieties, with a genetic signature unique to Chevalier, and where the name is a sort of brand name for a certain kind of product,” said Jenny Hagenblad, associate professor of population genetics at the Department of Physics, Chemistry and Biology (IFM) at Linköping University.



The researchers tested seeds from two different sources. Firstly, seeds were obtained from museum specimens of historical grains labeled “Chevalier.” These samples had been collected and stored at various times during the 19th century, with the oldest sample dating from 1865. Secondly, the researchers used seeds from current Chevalier accessions preserved in genebanks. In total, 282 individual seeds, representing 47 accessions, were used in the study.&nbsp;



Genetic analysis of the seeds revealed that many of them did indeed belong to a specific variety – Chevalier, and that this variety had been bred and kept pure for its superior malting qualities. From the very beginning, Chevalier was considered a premium malting barley and sold at higher prices than other cultivars. Farmers may have gone to great lengths to keep this cultivar pure, long before they knew the details of Mendelian inheritance or genes. In the light of these samples of pure Chevalier seeds, researchers were tempted to think it possible that a single plant may have given rise to all successive generations of this type of barley.&nbsp;



However, not all the sample jars marked “Chevalier” contained true Chevalier barley seeds.&nbsp;



Some of the samples contained unimproved landrace barley, representing the varieties that were present in Nordic countries before the introduction of the Chevalier cultivar. Other samples contained mixtures of Chevalier and landrace seeds, while a few samples also had seeds that were, hybrids (crosses) between Chevalier and other varieties.&nbsp;



From these results it was clear that the designation “Chevalier” was applied rather loosely in the 19th century. The seed mixtures indicated that, after the Chevalier variety was brought to Sweden, local farmers mixed it – deliberately or accidentally –with seeds from local landraces.&nbsp;



Although barley is usually self-fertilizing, there is a small incidence (2%) of cross-fertilization. This can lead to the development of a hybrid variety which would then have characteristics of both the Chevalier parent and the local landrace parent. The result would be a Chevalier-type malting barley that was also adapted to local environmental conditions. Not only did this generate new diversity from which farmers could obtain their future seeds, but hybrids often give increased yield as well.



According to the authors of the study, their findings indicate that farmers were practicing plant improvement methods long before there was an understanding of genetics. The processes used during the 1800s by farmers in Sweden were not very different from the plant improvement methods developed in the early 20th century, when genotypes superior in yield or quality were combined with locally adapted material to create the first modern cultivars.



“We can see signs of how people, long before the development of modern plant breeding, were already unwittingly using the very methods that became the foundation for the revolution in Swedish farming during the early 20th century,” said study co-author Matti Leino, a researcher in crop history at Stockholm University.



The results of the study have been published in the journal&nbsp;<a href="https://acsess.onlinelibrary.wiley.com/journal/14350653">Crop Science</a>.



---



By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Barley was bred for exceptional qualities in the 19th century

The story goes that, in 1820, a farmworker in the...

According to a new <a href="https://eia-international.org/report/connecting-the-dots-plastic-pollution-and-the-planetary-emergency/">report</a> by the <a href="https://eia-international.org/">Environmental Investigation Agency</a> (EIA), plastic pollution should be considered a planetary emergency. The experts are urging for a binding United Nations (UN) treaty to regulate the production, consumption, and environmental dispersal of the <a href="https://www.earth.com/news/birds-can-recognize-the-plants-that-host-toxic-insects/">toxic</a> plastic materials that are currently found in soils, foods, and even the air that we breathe (in the form of micro-particles).



The United Nations has identified three major “existential environmental risks” – climate change, loss of biodiversity, and pollution – and argued that they are intricately connected and should be addressed together. While formal multi-national agreements aiming to curb climate change and biodiversity loss have existed since over three decades, no treaty dedicated to plastic pollution has yet been proposed.



"There is a deadly ticking clock counting swiftly down," said Tom Gammage, a marine biologists and campaigner at EIA. "If this tidal wave of pollution continues unchecked,&nbsp;the anticipated plastics in the seas by 2040&nbsp;could exceed the collective weight of all fish in the ocean."



“The visible nature of plastic pollution has generated huge public concern but the vast majority of plastic pollution impacts are invisible,” he explained. "The damage done by rampant overproduction of <a href="https://www.earth.com/news/virgin-plastic-use-may-decrease-significantly-by-2025/">virgin plastics</a> and their lifecycle is irreversible - this is a threat to human civilization and the planet’s basic ability to maintain a habitable environment. It’s becoming almost as serious as the threat from climate change."



According to Professor Richard Thompson, an expert in plastics at the <a href="https://www.plymouth.ac.uk/">University of Plymouth</a>, advocating policies that would merely promote the use of recyclable plastics will not be effective if no local infrastructure to collect, separate, and viably recycle those plastics exists. The UN treaty should thus focus on the full life-cycle analysis of plastics, and addressing the highly unsustainable levels of production and consumption.



“The question now is, what will that treaty look like?” asked Trisia Farrelly, a plastics researcher at <a href="https://www.massey.ac.nz/">Massey University</a>, New Zealand. “Will there be a weak form that focuses on marine litter and waste management? Or will there be a resolution that includes the full life cycle of plastics including extraction and production right through to remediation of legacy pollution?"



Regardless of the form this treaty will ultimately take, “there is&nbsp;more than enough evidence&nbsp;to know that we have to act with urgency to prevent further irredeemable damage caused by plastics pollution," she concluded.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Plastic pollution is a planetary emergency

According to a new report by the Environmental Investigation Agency...

NASA’s <a href="https://mars.nasa.gov/msl/">Curiosity rover</a> landed on Mars almost a decade ago (on August 6, 2012), and since then it has collected a large variety of samples from the Gale Crater. In a new study published in the <a href="https://www.pnas.org/content/pnas/119/4/e2115651119.full.pdf">Proceedings of the National Academy of Sciences</a>, an international team of scientists has analyzed carbon isotopes from <a href="https://www.earth.com/news/bacteria-in-meltwater-sediments-speed-up-ice-loss-in-greenland/">sediment</a> samples taken by Curiosity from half a dozen exposed locations on Mars. 



According to the researchers, the presence of carbon on the surface of Mars has three possible explanations: cosmic dust, ultraviolet degradation of carbon dioxide, or ultraviolet degradation of biologically produced methane.&nbsp;



Carbon has two specific isotopes, 12 and 13. By analyzing the amounts of each isotope from a substance, scientists can understand more about the carbon cycle that occurred, even if it happened billions of years ago.&nbsp;



"The amounts of carbon 12 and carbon 13 in our solar system are the amounts that existed at the formation of the solar system," said study lead author Christopher H. House, a professor of Geosciences at the <a href="https://www.psu.edu/">Pennsylvania State University</a>. "Both exist in everything, but because carbon 12 reacts more quickly than carbon 13, looking at the relative amounts of each in samples can reveal the carbon cycle."



Some of the carbon found in samples collected by the Curiosity rover were exceptionally depleted in carbon 13, resembling samples taken in Australia that were 2.7 billion years old. “Those samples were caused by biological activity when methane was consumed by ancient microbial mats, but we can't necessarily say that on Mars because it's a planet that may have formed out of different materials and processes than Earth," said Professor House.



To explain the presence of these samples, House and his colleagues proposed three possible scenarios. Millions of years ago, Mars could have passed through a galactic molecular cloud which would have lowered the temperature on a planet still containing water, allowing for glaciers to form and dust to deposit on the top of the ice. When the glaciers melted, they could have left behind a layer of dirt containing the depleted carbon. However, there is still no evidence of the presence of glaciers on Mars.



A second hypothesis explaining the lower amounts of carbon 13 is the ultraviolet conversion of carbon dioxide to organic compounds such as formaldehyde. While previous studies suggest that ultraviolet conversion could cause this, more experimental results are needed to assess the plausibility of this scenario. Finally, the third explanation would indicate the presence of past microbes which consumed the methane released from the planet’s subsurface, giving rise to the depleted carbon.&nbsp;



"We need more data to figure out which of these is the correct explanation,” said Professor House. “It would be nice if the rover would detect a large methane plume and measure the carbon isotopes from that, but while there are methane plumes, most are small, and no rover has sampled one large enough for the isotopes to be measured.” Nevertheless, "all three possibilities point to an unusual carbon cycle unlike anything on Earth today."



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Carbon found on Mars sheds light on the planet’s history

NASA’s Curiosity rover landed on Mars almost a decade ago...

A new longitudinal study published in the <a href="https://dx.doi.org/10.1136/%20bjophthalmol-2021-319807">British Journal of Ophtalmology</a> has found that the difference between the biological age of the retina (the sensory membrane at the back of the eyeball responsible for vision) and a person’s chronological age is linked to their risk of <a href="https://www.earth.com/news/wildfires-in-the-west-linked-to-smoke-related-deaths-in-the-east/">death</a>. This “retinal age gap” could thus be used as a screening tool for early diagnosis and treatment of various life-threatening diseases.



Damage to the blood vessels in the retina can be early signs of several health problems, such as high blood pressure, coronary artery disease, nerve damage caused by diabetes, glaucoma or age-related macular degeneration, and even some types of cancer. Moreover, the state of the retina can indicate a person’s “biological age,” which is a measurement of age based on various biomarkers and is influenced by lifestyle and other health factors.



By analyzing the relationship between mortality and “retinal age gap” (the difference between the chronological and the biological age) in a cohort of 35,917 participants during a monitoring period of 11 years, the scientists found an unmistakable correlation between larger retinal age gaps and increased risk of death.&nbsp;



&nbsp;“The retina offers a unique, accessible ‘window’ to evaluate underlying pathological processes of systemic vascular and neurological diseases that are associated with increased risks of mortality,” wrote the study authors.



“This hypothesis is supported by previous studies, which have suggested that retinal imaging contains information about cardiovascular risk factors, chronic kidney diseases, and systemic biomarkers.”



According to the researchers, every one-year increase in the retinal age gap was associated with a two percent increase in the risk of death from any cause, and a three percent increase in the risk of death from a specific cause other than cardiovascular disease or cancer. Moreover, very large retinal age gaps were linked to 49 to 67 percent higher risks of death.



“Our novel findings have determined that the retinal age gap is an independent predictor of increased mortality risk, especially of non-cardiovascular disease/non-cancer mortality. These findings suggest that retinal age may be a clinically significant biomarker of ageing,” explained the study authors.



In conclusion, these findings add weight to “the hypothesis that the retina plays an important role in the ageing process and is sensitive to the cumulative damages of ageing which increase the mortality risk.”



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Retinal health is a good predictor of mortality

A new longitudinal study published in the British Journal of...

According to a new scientific review supported by <a href="https://www.coffeeandhealth.org/">the Institute for Scientific Information on Coffee (ISIC)</a>, drinking <a href="https://www.earth.com/news/drinking-coffee-protects-against-alzheimers-disease/">coffee</a> has many health benefits. Coffee consumption not only stimulates digestion and helps colon motility, but can also change the gut microbiota, increasing the number of “good bacteria” from our stomach. Moreover, it can protect against liver disease and reduce the risk of gallstones.



By reviewing 194 research articles, a team of scientists led by the <a href="https://www.inserm.fr/en/home/">French National Institute of Health and Medical Research</a> (INSERM) has found that drinking moderate amounts (three to five cups per day) of coffee can be highly beneficial for our health.&nbsp;



Most of the studies shown that coffee is associated with gastric, biliary, and pancreatic secretions, which are all crucial for the digestion of food. By stimulating the production of gastrin, hydrochloric acid, and cholecystokinin, coffee helps our organism properly digest a large variety of foods. Furthermore, coffee stimulates colon motility - the process through which food travels through our digestive tracts - and can thus reduce the risk of chronic constipation.



Drinking coffee regularly can also change the composition of gut microbiota, increasing the numbers of Bifidobacteria, inhabitants of our gastrointestinal tract that help break down food, absorb nutrients, and fight off pathogenic micro-organisms. Finally, although the evidence is still scarce, coffee may also help protect against more serious diseases, such as hepatocellular carcinoma.&nbsp;



&nbsp;“Contrary to some assumptions, coffee consumption is not overall linked to bowel or digestive problems. In some instances, coffee has a protective effect against common digestive complaints such as constipation,” explained study lead author Astrid Nehlig, the Emeritus Research Director of INSERM.



“Emerging data also indicate there may be an association with improved levels of gut bacterial groups such as Bifidobacteria which have recognized beneficial effects.&nbsp;Although additional data will be needed to understand coffee’s effects throughout the digestive tract, this is an extremely encouraging place to begin.”



The study is published in the journal <a href="https://www.mdpi.com/2072-6643/14/2/399">Nutrients</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Coffee stimulates digestion and protects against disease

According to a new scientific review supported by the Institute...

Observing animal <a href="https://www.earth.com/news/ocean-acidification-disrupts-the-behavior-of-fish-shoals/">behavior</a> and ecology in the wild is the basis of conservation planning. However, the cost, time commitment, and danger involved in basic observational work can make it extremely challenging.&nbsp;



Scientists often substitute observations with data collected through biologging devices. These high-tech devices can monitor heart rate, breathing, animal movement, and more. To accurately interpret data from logging devices, statistical analysis is needed. Like other scientific technologies, statistical tools are always evolving. A new study from the <a href="https://www.ubc.ca/">University of British Columbia</a> improves on statistical tools used for interpreting data from biologgers.&nbsp;&nbsp;



“The thing we really tackled with this paper was trying to get at some of those fine-scale behaviors that aren’t that easy to model,” said study lead author Evan Sidrow, a doctoral student in the UBC Department of Statistics.&nbsp;



“It’s a matter of finding behaviors on the order of seconds - maybe 10 to 15 seconds. Usually, it’s a matter of a whale looking around, and then actively swimming for a second to get over to a new location. We are trying to observe fleeting behaviors, like a whale catching a fish.”



The researchers improved a statistical tool based on a hidden Markov model, which is used to interpret animal movement datasets.



“Traditional hidden Markov models break down at very fine scales,” said Sidrow. “That’s because there’s structure in the data you can’t capture using the basic type of hidden Markov model. We’re trying to capture it with this model - we’re trying to account for this ‘wigglyness' that a traditional hidden Markov model wouldn’t be able to account for.”



Because modern data logging devices collect data almost continuously, an enormous amount of data points are collected in a relatively short period of time. The Markov model has a hard time interpreting such a large amount of data. The new statistical modeling method allows a finer scale look into the data, which produces greater information for conservation planning by decision makers, including those working on orca conservation.&nbsp;&nbsp;



"As a case study, we use this framework to model the fine-scale kinematic movements of a northern resident killer whale ( Orcinus orca) off the western coast of Canada," wrote the study authors.&nbsp; "Through simulations, we show that our model produces more interpretable state estimation and more accurate parameter estimates compared to existing methods."



According to study senior author Dr. Marie Auger-Méthé, the study is one of the first steps on the road to fully understanding why southern resident killer whales are not faring as well as their northern counterparts.



“Using our methods to detect when the animals are catching prey and to model their energy expenditure will be key to understanding the differences between these neighbouring whale populations,” said Dr. Auger-Méthé.



She explained that the next goal is to understand when the whales are capturing prey and applying the models to both northern and southern resident killer whale populations to see how they are behaving differently.



“The paper offers many ‘building block’ solutions that can be used together or independently,” said Dr. Auger-Méthé. “In essence, we are providing a toolbox to researchers using high-frequency movement data, and other similar high-frequency time series.”



The study is published in <a href="https://onlinelibrary.wiley.com/journal/1708945x">The Canadian Journal of Statistics</a>.



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By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

New statistical tool could improve killer whale conservation

Observing animal behavior and ecology in the wild is the...

Mammals in general are not able to digest cellulose, the carbohydrate that is found in the cell walls of plant cells. Even <a href="https://www.earth.com/news/large-herbivores-must-be-restored-to-balance-ecosystems/">herbivores</a>, such as cows, horses and elephants do not produce the enzyme that breaks down cellulose. Instead, mammals (including humans) need gut microbes to carry out this function and enable them to access the nutrients found inside plant cells.&nbsp;



Giant pandas (Ailuropoda melanoleuca) are unusual because they are bears, in the order Carnivora, but their diet consists entirely of bamboo leaves and shoots. Carnivores have short gastrointestinal tracts, geared for digesting animal flesh, and this makes the herbivorous diet of giant pandas even harder to process efficiently. Pandas are thus heavily dependent on the microbes in their guts for breaking down cells in leaves and shoots to make the contents available.



In the wild, pandas feed on fibrous old bamboo leaves for eight months of the year. This diet is poor in nutrients and contains almost no fat. However, during late spring and early summer the bears feed on new shoots that have a higher nutritional value that enables them to gain weight.&nbsp;



Previous research has shown that the gut microbiome of giant pandas changes between the leaf-eating season and the shoot-eating season. However, there has been no research on the effects of these seasonal changes on the body characteristics or physiology of the pandas.&nbsp;



A study published today in the journal&nbsp;<a href="https://www.cell.com/cell-reports/home">Cell Reports</a> addresses this gap in current understanding and finds that shifts in the gut microbes enable pandas to gain weight and store fat when bamboo shoots are available to eat.&nbsp;



“This is the first time we established a causal relationship between a panda’s gut microbiota and its phenotype,” said study first author Guangping Huang from the <a href="https://english.cas.cn/">Chinese Academy of Sciences</a>. “We’ve known these pandas have a different set of gut microbiota during the shoot-eating season for a long time, and it’s very obvious that they are chubbier during this time of the year.”



The team of scientists, led by Fuwen Wei at the CAS Institute of Zoology, has been studying wild giant pandas living in the Qinling Mountains in central China for decades. The team collected fecal samples from eight adult pandas during the leaf-eating season (14 samples) and the shoot-eating season (15 samples). These were assessed for the presence and numbers of different types of gut microbes.&nbsp;



Wei says that these wild pandas have distinctly different populations of gut bacteria in the two seasons. In particular, a significantly higher abundance of a bacterium called&nbsp;Clostridium butyricum&nbsp;is present in the gut during the shoot-eating season compared with during the leaf-eating season. Gas chromatography-mass spectrometry of the short-chain fatty acids in the feces also revealed that the fatty acids butyrate and acetate were present in greater amounts during shoot-eating season.



Although bamboo leaves and shoots contain almost no fat, pandas were able to gain weight and store fat when they preferentially ate shoots. The bacterium C. butyricum produces the fatty acid butyrate as a product of its metabolism in the gut of the pandas, and the scientists were interested in the effects of this fatty acid on panda metabolism.



To investigate whether the change in gut microbiota could affect a panda’s metabolism, the researchers performed a fecal transplant of panda feces, collected in the wild, to the intestinal tracts of germ-free mice. They introduced fecal matter from panda donors during the leaf-eating season into some mice, while other mice received feces collected from pandas during the shoot-eating season. A third group of mice – the control group – received no panda fecal matter.&nbsp; Then they fed the mice for 3 weeks with a bamboo-based diet that simulated what pandas eat. &nbsp;



The experts found that mice transplanted with panda feces collected during shoot-eating season gained significantly more weight and had more fat after 21 days than mice transplanted with feces from leaf-eating season, despite consuming the same amount of food. Further analysis revealed that the fatty acid butyrate, a metabolic product of&nbsp;C. butyricum, could upregulate (enhance) the expression of a gene called&nbsp;Per2, which increases lipid synthesis and storage. Thus, the mice showed the same patterns of seasonal weight gain as the pandas do, indicating the critical role of the gut microbiome in panda metabolism.



Fat storage is important in many animals that eat a nutrient-poor diet. The bamboo eaten by pandas in the wild is deficient in fat but the shoots, eaten in late spring and early summer, contain higher levels of protein and carbohydrate. The gut bacteria in these mammals enables them to use the protein and additional carbohydrates in the shoots, to synthesize lipids that are then available for storage.&nbsp;



Many animals experience a seasonal shift in gut bacteria as a result of changes in food availability. For example, certain species of monkeys have different gut microbiota in summer, when they eat fresh leaves and fruits, compared with that in winter, when they feed on leaves and tree bark. A similar shift has also been observed in the digestive systems of Hadza people, modern hunter-gatherers living in Tanzania, as the type of available food changes through the year.



The researchers plan to investigate and map out more microorganisms in the panda’s gut in future, and to find out how they affect the animals’ health. “Causal research of host phenotype and gut microbiota in wild animals is just beginning. Identifying what bacteria are beneficial for animals is very important, because one day we may be able to treat some diseases with probiotics,” said Huang.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Giant pandas’ gut bacteria turn nutrient-poor food into fat

Mammals in general are not able to digest cellulose, the...

The turning blades on wind turbines and drones make a <a href="https://www.earth.com/news/traffic-noise-linked-to-higher-risk-of-dementia/">noise</a>, as do the airfoils used on planes and helicopters. Most of the nose that arises as an object moves through air originates at the trailing edge as air flowing over and under the object meet. The same is true for the noise that a bird’s wings make as it flies overhead – except, of course, in the case of owls. They are renowned for being able to fly silently.



In&nbsp;a quest to design airfoils that produce less noise pollution, researchers from <a href="http://en.xjtu.edu.cn/">Xi'an Jiaotong University</a> mimicked the characteristics of owl wings to inform a new design of airfoil that significantly reduces the trailing-edge noise. Details of the study are published today in the journal <a href="https://aip.scitation.org/journal/phf">Physics of Fluids</a>.



“Nocturnal owls produce about 18 decibels less noise than other birds at similar flight speeds due to their unique wing configuration,” said study co-author Xiaomin Liu. “Moreover, when the owl catches prey, the shape of the wings is also constantly changing, so the study of the wing edge configuration during owl flight is of great significance.”



When air flows over the top of an airfoil-shaped surface, it forms a layer of turbulence. Similarly, air flowing underneath also forms a layer of turbulence, and these two layers meet at the trailing edge of the structure. When they meet and air flows back through the trailing edge, it scatters and radiates noise.&nbsp;



The wing feathers of owls form a serrated edge at the trailing end of the wing, and this is thought to minimize turbulence and the associated noise. Previous studies have explored the use of serrated trailing edges and found that the serrations effectively reduce the noise of rotating airfoils. However, the noise reduction was not universal, depending heavily on the way in which the airfoil was used.



“At present, the blade design of rotating turbomachinery has gradually matured, but the noise reduction technology is still at a bottleneck,” said Liu. “The noise reduction capabilities of conventional sawtooth structures are limited, and some new non-smooth trailing-edge structures need to be proposed and developed to further tap the potential of bionic noise reduction."



The researchers used noise calculation and analysis software to conduct a series of detailed theoretical studies of simplified airfoils that had characteristics reminiscent of owl wings. They applied their findings to suppress the noise of rotating machinery.



The study showed that improving flow conditions around the trailing edge of the airfoil and optimizing the shape of the edge did suppress the noise. The experts also found that asymmetrical serrations reduced the noise more than symmetrical serrations.&nbsp;



However, the extent of noise reduction varied with different operating conditions, so the scientists emphasized that the airfoil designs should be further evaluated based on the specific application for which they would be used.



For example, wind turbines have complex incoming flow environments that require a more general noise reduction technology. Examining noise reduction techniques under the influence of different incoming flows would make their conclusions more universal.



The researchers believe their work will serve as an important guide for airfoil design and noise control in the future.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Owl wings inspire noise reduction in wind turbines and aircraft

The turning blades on wind turbines and drones make a...

Many birds learn their songs in the same way that humans learn a language or dialect –from their parents and neighbors, through mimicry. According to most biologists, this is an uncertain and error-prone method, often resulting in slow but unmistakable changes in the nature of <a href="https://www.earth.com/news/humpback-whale-songs-are-used-to-locate-not-attract-other-whales/">songs</a> over the years.



However, new research led by the <a href="https://www.berkeley.edu/">University of California, Berkeley</a> has found that some isolated populations of double-collared East African sunbirds have been singing the same songs - passed down to each new generation - for up to a million years.&nbsp;



The amazingly static nature of their songs may be due to the birds’ unchanging environment. The birds have inhabited so-called sky islands on East African mountaintops since ancient times.



"If you isolate humans, their dialects quite often change; you can tell after a while where somebody comes from. And song has been interpreted in that same way," said study senior author Rauri Bowie, a professor of Integrative Biology at UC Berkeley. "What our paper shows is that it's not necessarily the case for birds. Even in traits that should be very labile, such as song or plumage, you can have long periods of stasis."



According to Professor Bowie and his colleagues, the idea that birdsong changes very often likely arose from studies of Northern Hemisphere birds, which have repeatedly encountered environmental changes, such as glaciers coming and going over the last thousands of years. These changing environmental conditions can cause significant modifications in plumage, song, and mating strategies.



However, since mountaintop environments in the tropics, particularly in East Africa (such as Mount Kenya or Kilimanjaro) have witnessed very little geological change over the millennia, the birds living there faced no evolutionary pressure to change their plumage or songs.



"We are showing, using a really nice setup where we could look at song evolution using naturally isolated populations, that [in East African sunbirds] you don't see this gradual change through cultural or genetic drift at all," Bowie said. "You see these sharp bursts of change in a trait such a birdsong and lots and lots of evidence for stasis, even when that trait should be very plastic. To me, that was a really fascinating result."



The study is published in the journal <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2021.2062">Proceedings of the Royal Society B</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

The song of the East African sunbird may be a million years old

Many birds learn their songs in the same way that...

The Atlantic Forest of Brazil, Argentina and Paraguay is quite threatened, so it’s no surprise that lowland tapirs in this <a href="https://www.earth.com/news/deforestation-exposes-coastal-cities-to-more-deadly-storms/">forest</a> are severely endangered as well. Although tapirs are adaptable and found in a wide variety of habitats across South America, they are still declining in numbers across their range. Lowland tapirs are now found in only 1.78 percent of their original range in the Atlantic Forest.&nbsp;



A new study published in the journal <a href="https://neotropical.pensoft.net/">Neotropical Biology and Conservation</a> warns of the dire need for conservation actions to protect lowland tapirs of the Atlantic Forest. The research was headed up by Dr. Kevin Flesher of Biodiversity Study Center, Michelin Ecological Reserve and Dr. Patrícia Medici of the <a href="https://tapirconservation.org.br/">Lowland Tapir Conservation Initiative</a>.



"Of the 48 tapir populations identified during the study, between 31.3% and 68.8% are demographically unviable (low number of individuals), and between 70.8% and 93.8% of the populations are genetically unviable (low gene flow). Only 3-14 populations are still viable in the long run when both criteria are considered. The evidence suggests that with the appropriate conservation actions, the lowland tapir could be broadly distributed throughout the Atlantic Forest," explained Dr. Flesher.&nbsp;



"Tapirs have low reproductive potential, including a long reproductive cycle with the birth of just one young after a gestation period of 13-14 months and intervals of up to three years between births. Our populational simulations clearly show how, in the case of small populations, even the loss of a single individual per year can result in rapid extinction of an entire local population," added Dr. Medici.&nbsp;



Dr. Flesher spent 15 years visiting 93 reserves in the Atlantic Forest, conducting interviews and analyzing 217 data sets to create a conservation plan for tapirs in the area. Unfortunately, tapirs in the states of São Paulo and Paraná in Brazil - where the largest number of populations remain - are isolated from each other.



"As far as our knowledge goes, there is no evidence of movement of tapirs between these populations," said Dr. Medici.&nbsp;



The fragmented populations aren’t connecting with each other, not because of great distances but the threat from cars involved. "The central problem is the multiple threats they face while crossing the habitat," said Dr. Flesher.&nbsp;



Highways and attendant motor traffic are a huge obstacle and threat to disbursing tapirs. "For example, the heavy traffic on highway BR-101 (which cuts the Brazilian Atlantic Forest from North to South) is a death trap to wildlife. Tapirs often die when attempting to cross it," explained Dr. Medici.&nbsp;



Highway traffic is a significant cause of death for tapirs in six out of eight reservations where highways cross tapir populations. However, the situation seems to call for a small amount of optimism. "Despite these continuing challenges for tapir conservation, most populations appear to be stable or increasing and the conservation outlook for the species is better than several decades ago, when the first efforts to protect the species began," said Dr. Flesher.



---By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lowland tapirs in the Atlantic Forest are at risk of extinction

The Atlantic Forest of Brazil, Argentina and Paraguay is quite...

Accidentally trapping marine animals such as sharks, seabirds, turtles, or sea mammals in fishing gear is one of the biggest barriers for making fisheries more sustainable. While <a href="https://marineprotectedareas.noaa.gov/">marine protected areas</a> are aiming to minimize accidental catch, they often prove to be quite inefficient in protecting marine biodiversity, particularly in the case of marine species that are very mobile and constantly travel between these static areas.&nbsp;



According to new research from the <a href="http://www.washington.edu/">University of Washington</a> (UW), “dynamic ocean management,” or the shifting of ocean closures, can be much more effective against accidental catch.



“We hope this study will add to the growing movement away from permanently closed areas to encourage more dynamic ocean management,” said study senior author&nbsp;Ray Hilborn, a professor at the UW <a href="https://fish.uw.edu/">School of Aquatic and Fishery Sciences</a>. “Also, by showing the relative ineffectiveness of static areas, we hope it will make conservation advocates aware that permanent closed areas are much less effective in reducing accidental catch than changes in fishing methods.”



Professor Hilborn and his colleagues investigated 15 fisheries around the world, and modelled what would happen both to targeted fish and accidental catches (or “bycatch”) if 30 percent of the fishing grounds were permanently closed, compared with dynamic management. They found that restricting fishing by 30 percent would only diminish bycatch by 16 percent, in contrast to using dynamic closures, which could reduce accidental catch by a staggering 57 percent.



“We found we can significantly reduce bycatch without decreasing the catch of target species by closing small fishing areas that can move year to year,” said study lead author&nbsp;Maite Pons, who completed this article as a UW postdoctoral fellow. “This dynamic approach is increasingly valuable as climate change drives species and fisheries into new habitats, altering these interactions.”



However, the authors acknowledge that, in some cases, static protected areas may remain the best choice. If the main purpose is to protect a critical habitat, a biodiversity hotspot, or a critical feature, static closures might remain most effective and easier to implement. Thus, all conservation goals should be broadly considered before determining which types of ocean protections are best in a specific situation.



&nbsp;---



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Dynamic ocean closures offer protection from accidental catch

Accidentally trapping marine animals such as sharks, seabirds, turtles, or...

Go to any natural history museum, watch any dinosaur movie, and undoubtedly the big bad will be a <a href="https://www.earth.com/news/flesh-eating-theropods-were-extremely-fast/">theropod</a>. This terrifying, exceptionally toothy group includes Tyrannosaurus, Velociraptor, Allosaurus, and many others. Paleontologists are finally unraveling how the murderous jaws of these predatory dinosaurs evolved.



A new study, published in the journal <a href="https://www.cell.com/current-biology/home">Current Biology</a> looked at the lower jaws of over 40 theropod dinosaur species. While the most well-known theropods are big and toothy, they also came in many shapes and sizes. Some were small, and some were, in fact, toothless.&nbsp;



By running the different jaws through computer modeling to test their strength, the researchers found that over the course of their evolution, theropod jaws grew progressively stronger. The predatory dinosaurs expanded the rear, or posterior, portion of their jaws (sideways or laterally), and the mechanical strength increased over the course of their over 100-million year history.&nbsp;



“Although theropod dinosaurs are always depicted as fearsome predators in popular culture, they are in fact very diverse in terms of diets. It is interesting to observe the jaws becoming structurally stronger over time, in both carnivores and herbivores. This gives them the capacity to exploit a wider range of food items," explained study lead author Dr. Fion Waisum Ma of the <a href="https://www.birmingham.ac.uk/index.aspx">University of Birmingham</a>.



"Theropod dinosaurs underwent extreme dietary changes during their evolutionary history of 165 million years. They started off as carnivores, later on evolved into more specialized carnivores, omnivores and herbivores. Studying how their feeding mechanics changed is key to understanding the dietary transitions in other vertebrate animals too.”



While it makes sense that the hypercarnivorous meat-eaters would increase their lower-jaw strength, the herbivorous lineages also developed stronger jaws.&nbsp;



“It is fascinating to see how theropod dinosaurs had evolved different strategies to increase jaw stability depending on their diet," said study co-author Dr. Stephan Lautenschlager. "This was achieved through bone remodeling – a mechanism where bone is deposited in regions of the jaw that experience high stresses during feeding.”&nbsp;



This evolutionary pattern is reflected in the ontogeny, or growth, of the individual animals. For example, juvenile tyrannosaurs possessed proportionally slimmer and downturned jaws compared to adult individuals.&nbsp;



“The similarity between jaw strengthening through growth and through time suggests that developmental patterns in juvenile dinosaurs ultimately affected the evolution of the whole group," concluded Dr. Lautenschlager&nbsp; "This likely facilitated the jaw evolution of theropod dinosaurs and their overall success for over 150 million years.”



---



By <a href="http://mailto:rugerpaleo@gmail.com">Alex Ruger</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Jaws of predatory dinosaurs grew stronger as they evolved

Go to any natural history museum, watch any dinosaur movie,...

We live in a diverse world with different ecosystems and <a href="https://www.earth.com/news/shrinking-habitats-alien-species-threaten-native-trout/">habitats</a>. For centuries, scientists have been studying how flora and fauna interact within these natural communities. Some animals are creatures of habit who frequently eat in the same spots, travel on the same roads, and raise their young in the same places. The term "site fidelity" is used by ecologists to characterize the behavior of animals who are fixed in their routines and tend to return to a previously occupied location. 



The habit of many animals, from fish to birds to mammals and insects, to return to regularly frequented areas. Site fidelity is everywhere in nature, whether it's salmon returning to their native streams to breed or birds returning year after year to the same nest site.



According to a new study, while this "consistent" behavior may be beneficial when environmental conditions aren't changing rapidly, the benefits may not be realized in the ever-changing world dominated by humans. The research was focused on a literature review led by the <a href="http://www.uwyo.edu/">University of Wyoming</a>.



When animals get familiar with a location, site fidelity can help them figure out where to obtain good food or safe havens from predators, as well as how to get to and from these resources quickly. On the other hand, the research team discovered a new trend in the scientific literature.



“Animals that have strong site fidelity are having a tough time adjusting to the novel landscapes that are showing up around them as a result of humans,” said study co-lead author Professor Jerod Merkle.



The researchers pointed out that animals with strong site fidelity may not survive or reproduce as well as animals with more flexible behaviors when faced with human disturbances or climate change. When a population consists of a large number of site loyalists, a population decrease might occur due to the changes in the environment.



For instance, there are numerous mule deer winter ranges in Wyoming. With the addition of large natural gas fields, mule deer can make slight range adjustments to avoid infrastructure, but they stick to the same general area rather than abandoning it completely. The continued use of those damaged places may have detrimental implications. In one long-term study, researchers discovered a 40% drop in the mule deer population following large-scale energy development in their winter area.



Climate change also plays a major role in the adverse impacts on site-fidel animals. Under normal climate circumstances, site fidelity is a winning strategy for female northern elephant seals in the Pacific Ocean. In average years, site-faithful seals are better able to acquire food and gain fat compared to their more flexible cousins. But when aberrant climate events - such as extreme El Nios - induce major changes in the ocean ecology, behaviorally flexible seals win out. Female seals with strong site fidelity are unable to gain as much vital fat as they require to reproduce.



“Despite each of us working on very different species from one another, our group came together because we all recognized that there was a clear connection between strong site fidelity and species declines," said study co-lead author Briana Abrahms, an assistant professor at the University of Washington.



"We all thought it was important to call attention to this connection for other researchers and wildlife managers. Recognizing the types of species or behaviors that may suffer most from human-induced environmental change can help develop conservation priorities and actions."



While the analysis paints a bleak picture of the future for animals with high site fidelity, they also offer hope. The experts noted that occasionally, an animal will try something new and succeed. While such instances are uncommon, those "innovators" can be critical to a company's long-term survival in a changing environment.



"While these species appear to be stuck in their ways, many of them also have some unique but subtle ways of dealing with change,” said study co-author Jonathan Armstrong, an assistant professor at Oregon State University. “We just have to be patient and make sure populations don’t crash before such innovators come along,” Armstrong added.



The researchers offer a number of recommendations for researchers and practitioners towards the end of their paper. To begin, long-term monitoring is essential for determining how individuals and populations react to change. Second, they argue that biologists should not always expect animals to use and discover the optimal habitats. This is especially crucial when it comes to restoring new habitat regions, which may not work well for species with high site fidelity because they may not be able to "discover" these regenerated habitats.



As a result, the study authors propose that, rather than off-site mitigation, the conservation of species with high site fidelity should focus on the protection and restoration of highly frequented locations.



The study is published in the journal <a href="https://www.esa.org/frontiers-in-ecology-and-the-environment/">Frontiers in Ecology and the Environment</a>.



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By <a href="http://mailto:ashikha92@gmail.com">Ashikha Raoof</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Animals with strong site fidelity face an uncertain future

We live in a diverse world with different ecosystems and...

Osteoarthritis (OA) affects 45 percent of all cats, and over 90 percent of those older than 12. The condition is caused by the breakdown of cartilage cushion surrounding the joints, which makes the bones rub against each other, leading to chronic <a href="https://www.earth.com/news/why-does-our-breathing-rate-increase-when-we-feel-pain/">pain</a> and decreased joint movement.&nbsp;&nbsp;



The traditional medical treatments for cat arthritis consist of animal-specific nonsteroidal anti-inflammatory drugs (NSAID), similar to ibuprofen. These drugs can only be used safely for a short period of time, and cannot be given to cats suffering from kidney disease (which is another very common cat affliction).



However, a new drug manufactured by the company <a href="https://www.zoetis.com/index.aspx">Zoetis</a> has now been approved by the <a href="https://www.fda.gov/">U.S. Food and Drug Administration</a> (FDA). Solensia is a cat-specific monoclonal antibody that is injected by the veterinary under the skin once a month, and appears to be highly effective in diminishing the pains caused by OA and thus improving the animals’ mobility and overall quality of life. In two clinical trials, 77 percent of cat owners saw significant improvements in their pets after treatment with Solensia, compared to 67 percent in the placebo groups.



“Feline (arthritis) pain is typically undertreated because of a lack of effective solutions that are safe to use long-term, along with how difficult it can be for cat owners to administer oral medicines,” said Mike McFarland, chief medical officer at Zoetis. “The approval of Solensia is a significant step forward.”



“This is absolutely groundbreaking,” added Dr. Duncan Lascelles, a professor of Translational Pain Research and Surgery at the North Carolina State College of Veterinary Medicine. “I have been in pain research for 30 years and this is the most exciting development that has happened.”



“To be able to be mobile is so desperately important to the quality of life. Cats are described as needing 3D spaces. They need to move on the ground but they also need to be able to get to elevation.”&nbsp;



“Finally, for the first time ever in the U.S., there’s a highly efficacious treatment to manage joint pain in cats. And therefore extend their life, extend their happiness, and extend that beautiful relationship between cats and their owners,” Dr. Lascelles concluded. &nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Revolutionary treatment greatly extends the lives and happiness of cats

Osteoarthritis (OA) affects 45 percent of all cats, and over...

New research led by a team of biologists from the <a href="https://www.utah.edu/">University of Utah</a> has found that California mice eat <a href="https://www.earth.com/news/how-predators-have-outsmarted-monarch-butterflies/">monarch butterflies</a> that fall to the ground. This is despite the fact that these butterflies possess a potent “chemical armor” from eating milkweed with toxic cardenolides. The milkweed toxins build up in their bodies and make monarchs unpalatable to most (but not all) predators.



Scientists have long observed that in Central Mexico, the place with the largest winter aggregations of monarchs, the black-eared mouse (Peromyscus melanotis) eats up to 40 of these butterflies each night. More recently, researchers found that the western harvest mouse (Reithrodontomys megalotis) also consume grounded monarchs at the Pismo State Beach Monarch Butterfly Grove in California.



To study mice-monarch interactions, the researchers first trapped rodents in the grove in February 2020 and screened their feces for monarch DNA, which they found in one sample. The scientists intended to return the next year, but unfortunately, after years of gradual decline, the monarch population finally crashed.



"At a site where 100,000 butterflies used to roost, in 2020 there where were fewer than 200 monarchs. So, we had to change tactics," said study lead author Sara Weinstein, a postdoctoral researcher at the University of Utah. "We tested whether rodents would feed on the butterflies using captive-reared monarchs."



Weinstein and her colleagues found that rodents that were offered monarchs ate them, usually favoring high-calorie parts with fewer toxins such as the abdomen or thorax. "Many rodent species are likely to have some resistance to cardenolides in monarchs, due to genetic changes at the site where these toxins bind," explained Dr. Weinstein.&nbsp;



"The Pismo Grove is one of hundreds of western monarch aggregation sites, and it seems likely that, at least in the past, rodents throughout the western monarch range may have supplemented their winter diets with monarchs. If you can handle the cardenolides in a monarch, their bodies are full of fat and offer a pretty good meal."



The massive decline of monarch populations is only one example of an ongoing “insect <a href="https://www.earth.com/news/the-sixth-mass-extinction-is-currently-in-progress/">apocalypse</a>.” According to Dr. Weinstein, about 40 percent of invertebrate species are currently threatened and over 70 percent of flying insect biomass may already be gone. “This is devastating on its own and is also going to have enormous impacts on the other organisms that feed on insects," Dr. Weinstein said.



"Western monarchs and other western butterflies need conservation attention and part of that awareness-raising is illuminating the many ways these animals are interconnected to other insects, birds, mammals, as well as our human communities. This study helps us appreciate more deeply how fewer butterflies means less food for other native animals," added Emma Pelton, a senior conservation biologist at the <a href="https://www.xerces.org/">Xerces Society for Invertebrate Conservation</a>.&nbsp;



The study is published in the journal <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.3607">Ecology</a>.



---



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

California mice can feed on poisonous monarch butterflies

New research led by a team of biologists from the...

In a new study from the <a href="https://www.uc.edu/">University of Cincinnati</a>, researchers have discovered that a type of brightly colored jumping spider is <a href="https://www.earth.com/news/dinosaurs-may-have-had-pops-of-color-like-modern-ducks/">color</a> blind. The study was focused on Saitis barbipes, a common jumping spider found in Europe and North Africa. 



The males of this species have a furry red crown and legs. They are known for performing elaborate courtship dances.



“We assumed they were using color for communication. But we didn’t know if their visual system even allowed them to see those colors,” said study co-first author David Outomuro.



Using microspectrophotometry to examine jumping spiders collected in Slovenia, the team found no evidence of a red photoreceptor. The experts also looked for colored filters that might shift green sensitivity to red, but found that there were none.



The researchers ultimately determined that, most likely, bright red colors appear no different than black markings to these jumping spiders.



"To quantify and visualize whether females may nevertheless be capable of discriminating red from black color patches, we take multispectral images of males and calculate photoreceptor excitations and color contrasts between color patches," explained the study authors&nbsp;&nbsp;



"Red patches would be, at best, barely discriminable from black, and not discriminable from a low-luminance green."



“It’s a bit of a head-scratcher, what’s going on here,” said study co-author Professor Nathan Morehouse. “We haven’t solved the mystery of what the red is doing.”&nbsp;



Even though animals use color in all sorts of ways, including camouflage, it’s not always apparent what bright colors might signify, according to Professor Morehouse. “We spent a lot of time talking about it as a group. What else could it be? I feel there’s an interesting story behind the mystery."



Study senior author Cynthia Tedore, a research associate at the University of Hamburg, said the results of the research were surprising.



“Males have bold red and black coloration on their forward-facing body surfaces which they display during their courtship dances; whereas, females lack red coloration altogether. This initially suggested to us that the red color must play some role in mate attraction," said Tedore.



“Instead, we found that red and black are perceived equivalently, or nearly so, by these spiders and that if red is perceived as different from black, it is perceived as a dark ‘spider green’ rather than red."



The researchers believe that the spider’s red and black colors may possibly improve defensive camouflage.



“For predators with red vision, at natural viewing distances, the spider's red and black color patches should blur together to become an intermediate orangish-brownish color, which would help the spider blend in with its leaf litter habitat better than all-black coloration would,” said Tedore.



The experts noted that there are many colorful jumping spiders that see red perfectly well. There are also many dull-colored spiders that have great color vision.



The study is published in the journal <a href="https://www.springer.com/journal/114">The Science of Nature</a>.



---



By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Scientists find a colorful jumping spider that is color blind

In a new study from the University of Cincinnati, researchers...

A new study from <a href="https://www.anu.edu.au/">Australian National University</a> (ANU) creates a stark choice: step up conservation efforts or lose the regent honeyeater, a beautiful <a href="https://www.earth.com/news/songbirds-and-humans-use-similar-speech-patterns/">songbird</a>, within 20 years. The new study reveals that even the current intensive conservation efforts aren’t enough.



“The regent honeyeater population has been decimated by the loss of over 90 per cent of their preferred woodland habitats,” said study lead author Professor Rob Heinsohn.



"Less than 80 years ago, it was one of the most commonly encountered species, ranging from Adelaide to Rockhampton. Now it is on track to follow the dodo into extinction.”



There are currently less than 300 regent honeyeaters left, making it one of Australia’s rarest birds. Habitat destruction forces the remaining honeyeaters to compete with larger birds for less habitat.



In 2015 the ANU researchers began an intensive research project focused on gaining greater understanding of the regent honeyeater’s decline. After years of field work, the scientists discovered that the decline in nest success was due to predation by other bird species and possums.&nbsp;



In the new research, the scientists used their hard won field data to create a population model that predicts the bird’s future population.&nbsp;



“Our models show that current conservation efforts have provided essential life support for the regent honeyeaters, but do not go far enough," said study co-author Dr. Ross Crates. “We were able to isolate the three key conservation priorities necessary to secure the birds’ future."&nbsp;



The first conservation priority the research lays out is a doubling of nest success rates in both wild and zoo bred animals, facilitated by protecting the nests from predators.&nbsp;



Next captive breeding efforts releasing birds into the Blue Mountains must increase and remain steady for twenty years in addition to nest protection.&nbsp;



Lastly, the research emphasizes that the regent honeyeater can only survive into the future if more habitat is preserved and restored.&nbsp;



“Without more habitat, reintroductions and nest protection efforts will be futile, because the flock sizes will never reach the critical mass needed for the birds to breed safely without our protection," said Professor Heinsohn.&nbsp;&nbsp;



"Our study provides both hope and a dire warning - we can save these birds, but it will take a lot of effort and resources over a long time to pull it off.”&nbsp;



The study is published in the journal <a href="https://www.journals.elsevier.com/biological-conservation">Biological Conservation</a>.



---



By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

How can we save the regent honeyeater from extinction?

A new study from Australian National University (ANU) creates a...

According to current scientific knowledge, the history of life on Earth was marked until now by five mass <a href="https://www.earth.com/news/volcanic-fertilization-led-to-severe-mass-extinction-event/">extinctions</a>, which were caused by natural phenomena and resulted in great global losses of biodiversity. In a new study, a group of biologists from <a href="https://manoa.hawaii.edu/">University of Hawai‘i at Mānoa</a> and the <a href="https://www.mnhn.fr/en">National Museum of Natural History</a> in Paris, France, argue that we are currently experiencing a Sixth Mass Extinction which, in contrast to the previous ones, is caused entirely by human activities.



By extrapolating from estimates obtained through the analysis of snail and slug populations, the scientists have shown that, since 1500, the Earth could have lost between 7.5 percent and 13 percent of the approximately two million of known species, thus between 150,000 to 260,000 species.



“Drastically increased rates of species extinctions and declining abundances of many animal and plant populations are well documented, yet some deny that these phenomena amount to mass extinction,” said&nbsp;study lead author Robert Cowie, a research professor of Biosciences at the University of Hawai’i.



“This denial is based on a biased view of the crisis which focuses on mammals and birds and ignores invertebrates, which of course constitute the great majority of biodiversity. Including invertebrates was key to confirming that we are indeed witnessing the onset of the Sixth Mass Extinction in Earth’s history.”



According to Professor Cowie and his colleagues, the situation is not the same everywhere on Earth. Although increasingly more marine species are threatened, the crisis affecting the seas and oceans is not so severe as that impacting the land. Moreover, on land, island species are more affected than continental ones, and a much larger number of terrestrial animals are endangered in comparison to plants.



Unfortunately, this ongoing extinction is denied by most of the people, including key political actors and policy-makers, and while conservation initiatives have been successful for certain charismatic animals, they cannot target all endangered species and reverse the overall thread of extinction.



“Despite the rhetoric about the gravity of the crisis, and although remedial solutions exist and are brought to the attention of decision-makers, it is clear that political will is lacking,” said Professor Cowie. “Denying the crisis, accepting it without reacting, or even encouraging it constitutes an abrogation of humanity’s common responsibility and paves the way for Earth to continue on its sad trajectory towards a Sixth Mass Extinction.”



The study is published in the journal <a href="https://onlinelibrary.wiley.com/doi/10.1111/brv.12816">Biological Reviews</a>.&nbsp;&nbsp;&nbsp;



---



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

The Sixth Mass Extinction is currently in progress

According to current scientific knowledge, the history of life on...

When wild creatures gather at watering holes, they also bring along their parasites, according to a new study from <a href="https://www.ucsb.edu/">UC Santa Barbara</a>. The experts report that cattle and elephants have the highest increased risk of exposure to the <a href="https://www.earth.com/news/if-primates-go-extinct-so-will-their-parasites/">parasites</a>.&nbsp;



"We think about watering holes as being iconic centers of these majestic animals, but they are also hotspots for the parasites that infect these animals," said study co-author Georgia Titcomb.&nbsp;



The researchers set out to investigate how watering holes may influence the distribution of the parasites across savannas in central Kenya.&nbsp;



The study revealed that parasite density is much higher around water sources compared to the surrounding landscape. The exposure risk varied among animal species, and the results suggest that cattle and elephants have by far the greatest risk. In fact, potential parasite exposure for cattle was 143 times higher, and 67 times higher for elephants.&nbsp;



Titcomb said she expected watering holes to aggregate parasites, leading to higher exposure for hosts. "But we didn't expect quite the degree of variation among different wildlife species. The animals that were most strongly affected, and that really followed our expectations, were ones that are quite water dependent: elephants and cattle."



The researchers also surveyed 17 watering holes and 17 dry locations at the Mpala Research Centre, in central Kenya, as well as three wet and dry sites at Ol Pejeta Conservancy. The team found that in the driest areas and time periods, parasite density around water sources was more than 150 times higher than that of locations without water.



"If a cattle herder wants to reduce the chances that their cattle are exposed to parasites, they may want to avoid grazing their animals within 150 meters of water," said Titcomb.&nbsp;



Next, she hopes to investigate how parasite infections in cattle might affect wildlife. "Because cattle are so numerous, their infection patterns have really strong potential to affect less numerous wildlife in the area."



The study is published in the journal <a href="https://www.nature.com/ncomms/">Nature Communications</a>.



---



By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

When animals flock to watering holes, so do their parasites

When wild creatures gather at watering holes, they also bring...

Many animal species exhibit behaviors that are linked to moon phases. A new study led by <a href="https://www.lsu.edu/">Louisiana State University</a> (LSU) and the <a href="https://www.ufl.edu/">University of Florida</a> is one of the first to investigate the connections between lunar phases and shark attacks. The findings suggest that more shark attacks occur during fuller phases of the moon.



The researchers analyzed a global shark attack record (<a href="https://www.floridamuseum.ufl.edu/shark-attacks/">The International Shark Attack File</a>) collected during over half a century (from 1960 to 2015) and discovered an unmistakable correlation between a large number of these attacks and periods with higher lunar illumination. However, it is not yet clear what the precise cause of this phenomenon is.&nbsp;



“It’s not a matter of more light at night for sharks to see. Most shark attacks occur in the daylight. However, the moon can exert other forces on Earth and its oceans in ways that are much more subtle—for example, the gravitation pull that we see affect the tides,” explained study co-author Steve Midway, an associate professor of Fisheries Ecology and Statistics at LSU.



According to Professor Midway and his colleagues, it is still too early to claim that lunar illumination is a causative factor for shark attacks. Since the relationship between moon phases and shark attacks may not be causal, scientists are not necessarily claiming that there are any immediate risk management benefits arising from these findings. Yet, the study contributes to a better understanding of shark behavior, which could help risk management in the future.



“Ultimately, moon phase and lunar illumination will not likely be a strong predictor that alone can forecast risk of shark attack. Local environmental variables are expected to continue to be more practical information for assessing risk.”&nbsp;



“However, the results here strongly support the idea that moon phase does play a role in overall risk of shark attack, and if future studies are able to consider local and regional environmental conditions along with lunar illumination, both understating shark attacks and forecasting risk may improve,” the authors concluded.



The study is published in the journal <a href="https://www.frontiersin.org/articles/10.3389/fmars.2021.745221/full">Frontiers in Marine Science</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Shark attacks linked to phases of the Moon

Many animal species exhibit behaviors that are linked to moon...

Eyes are important. They help <a href="https://www.earth.com/news/some-plants-wont-survive-the-loss-of-seed-dispersing-animals/">animals</a> find food and avoid becoming a meal themselves. Eyes also help animals scope out potential mates and watch out for rivals.&nbsp;



Looking into the eyes of a fossil can thus tell you a lot about how the creature once lived. Was the animal nocturnal or diurnal? An active hunter or shy and retiring? Unfortunately, however, eyes are rare fossils and scientists don’t often get an opportunity to look at them.&nbsp;



A research team spent years examining the eyes of a 95-million-year-old fossil crab,&nbsp;Callichimaera perplexa, found in the Colombian Andes. The crab was first described in 2019 by Harvard postdoctoral fellow Javier Luque. The fossil had preserved unusual elements of both the outer eye and internal structures.&nbsp;



In a new study led by Luque and scientists at Yale University, it is suggested that Callichomaera perplexa was a rare, active swimming predator. Much of this conclusion comes from examination of the eyes, which are quite large for those of an adult crab.&nbsp;



To make sure that they were in fact looking at an adult crab rather than an immature stage where eyes appear larger, Yale PhD candidate Kelsey Jenkins examined more than 1,000 crab specimens, both living and extinct. The research involved looking at crabs at different stages of development to finally determine that indeed, Callichomaera perplexa was an adult with exceptionally large eyes.&nbsp;&nbsp;&nbsp;



“Having such big and unprotected eyes implies that they were exposed at all times, plus eyes that big impose a huge investment of energy and resources to maintain them. Thus, this animal must have relied considerably on vision,” said Luque.



&nbsp;“If something has eyes this big, they're definitely very highly visual. This is in stark contrast to crabs with tiny, vestigial eyes where they may only be 1 to 3% of the animal's body size,” said Jenkins.



Further research showed that the crab had high visual acuity, comparable to other predators such as dragonflies and mantis shrimp. Its vision was adapted to high light environments, meaning the animal was probably most actively hunting during the day.&nbsp;



“Even though it’s the cutest, smallest crab, the big eyes of Callichimaera and its overall body form with unusually large oar-like legs indicate that it might have been a fierce, swimming predator, rather than a bottom-crawler as most crabs are,” said Luque.



Image Credit: Masato Hattori



---



By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Secrets of a big-eyed crab fossil revealed

Eyes are important. They help animals find food and avoid...

In the past, when climates changed, forests became distributed more to the north or to the south of their previous locations. This is not to say that the trees, themselves, moved. Rather, the ranges of the tree species changed. For example, fossil plant and pollen records show that the ranges of tree species shifted northward at a rate of 50km per century as the climate warmed after the retreat of the North American ice cap.&nbsp;



Tree range migration is facilitated by the movement of seeds. When the climate changes, trees begin to form more seeds; these get spread around by dispersal agents and may germinate in areas that are more favorable for growth. Although wind and water may carry some seeds, the vast majority of trees depend on animals to disperse them to new areas. But now, many of these seed-dispersing animals are themselves threatened, as climate changes and habitats are lost.



In&nbsp;<a href="http://www.science.org/doi/10.1126/science.abk3510?adobe_mc=MCMID%3D84587913426847399401258317155412422308%7CMCORGID%3D242B6472541199F70A4C98A6%2540AdobeOrg%7CTS%3D1641994662">a study</a>&nbsp;featured on the cover of this week’s issue of&nbsp;<a href="https://www.science.org/">Science</a>, U.S. and Danish researchers consider how the loss of species of birds and animals will impact the ability of plants to adapt to human-induced climate change in future. While animals can often fly, walk, run or swim to more suitable areas, trees cannot escape the heat. Tree species that need to move their offspring away from warmer temperatures will only be able to do so via the activities of seed-dispersal agents, such as mammals and birds.&nbsp;



“Some plants live hundreds of years, and their only chance to move is during the short period when they're a seed moving across the landscape,” said <a href="https://www.rice.edu/">Rice University</a> ecologist&nbsp;<a href="https://www.evanfricke.com/">Evan Fricke</a>, the study's first author. “If there are no animals available to eat their fruits or carry away their nuts, animal-dispersed plants aren’t moving very far."



In collaboration with researchers from the University of Maryland, Iowa State University and Aarhus University, the Rice team used machine learning and data from thousands of field studies to map the contributions of seed-dispersing birds and mammals worldwide. They compared maps of seed dispersal today with maps showing what dispersal would look like if there were no human-caused extinctions or species range restrictions.



The experts also used data synthesized from field studies around the world to train a machine-learning model for seed dispersal, and then used the trained model to estimate the loss of climate-tracking dispersal caused by animal declines.



Fricke explained that developing estimates of seed-dispersal losses due to animal and bird extinctions or changes in their ranges required two significant technical advances: “First, we needed a way to predict seed-dispersal interactions occurring between plants and animals at any location around the world."



For this, they used data on species interactions from over 400 field studies that detailed how many seeds are dispersed by particular species of birds and mammals, how far they are dispersed and how well those seeds germinate. Based on this data, the researchers could predict interactions between plants and seed dispersers.



“Second, we needed to model how each plant-animal interaction actually affected seed dispersal,” said Fricke. “For example, when an animal eats a fruit, it might destroy the seeds or it might disperse them a few meters away or several kilometers away.”



The results of the study showed that many seed-dispersing mammals and birds have already been lost, particularly in temperate regions across North America, Europe, South America and Australia. In addition, if currently endangered species go extinct, tropical regions in South America, Africa and Southeast Asia would be severely affected.&nbsp;&nbsp;



“We found regions where climate-tracking seed dispersal declined by 95%, even though they’d lost only a few percent of their mammal and bird species,” said Fricke.&nbsp;



The findings showed that the ability of animal-dispersed plants to keep pace with climate change has been reduced by 60% due to the loss of mammals and birds that help such plants adapt to environmental change.&nbsp;



“In addition to the wake-up call that declines in animal species have vastly limited the ability of plants to adapt to climate change, this study beautifully demonstrates the power of complex analyses applied to huge, publicly available data,” said Doug Levey, program director of the National Science Foundation’s (NSF) Directorate for Biological Sciences, which partially funded the work.



Fricke explained that the study is the first to quantify the scale of the seed-dispersal problem globally and to identify the regions most affected. He emphasized that declines in the populations of seed dispersers highlight an important intersection between the climate and biodiversity crises impacting natural environments today.



“Biodiversity of seed-dispersing animals is key for the climate resilience of plants, which includes their ability to continue storing carbon and feeding people,” he said, adding that restoration of ecosystem connections in natural habitats could counteract some declines in seed dispersal, but not all of them. People also rely, both economically and ecologically, on seed-dispersing birds and mammals to ensure the supply of important resources.&nbsp;



“Large mammals and birds are particularly important as long-distance seed dispersers and have been widely lost from natural ecosystems,” said Svenning, the study’s senior author. “The research highlights the need to restore faunas to ensure effective dispersal in the face of rapid climate change.”&nbsp;



“When we lose mammals and birds from ecosystems, we don’t just lose species. Extinction and habitat loss damage complex ecological networks," said Fricke. "This study shows animal declines can disrupt ecological networks in ways that threaten the climate resilience of entire ecosystems that people rely upon.”



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Some plants won't survive the loss of seed-dispersing animals

In the past, when climates changed, forests became distributed more...

Bald eagle populations have steadily increased in recent decades, after the use of DDT was banned in 1972. However, according to a new study led by <a href="https://www.cornell.edu/">Cornell University</a>, this rebound is currently weakened by the threat of lead <a href="https://www.earth.com/news/poisonous-frogs-warmer-temperatures/">poisoning</a> from gunshot ammunition.&nbsp;



Despite increasing numbers of bald eagles, lead poisoning from eating dead carcasses or parts contaminated by lead ammunition has reduced eagle population growth by 4 to 6 percent annually in the Northeast United States.



“Even though the population seems like it’s recovered, some perturbation could come along that could cause eagles to decline again,” said study senior author Krysten Schuler, an assistant professor in the <a href="https://www.vet.cornell.edu/departments/public-ecosystem-health">Department of Public and Ecosystem Health</a> at Cornell University.



Besides being potentially threatened by habitat loss, climate change, or the West Nile virus and other viral or bacterial outbreaks, bald eagles are increasingly affected by current hunting practices. Many hunters “field dress” game they shot with lead ammunition, leaving contaminated organs where the animal was killed. Bald eagles are scavenging such carcasses, often consuming bullet fragments that later on cause lead poisoning.



Although bald eagle numbers nearly <a href="https://news.cornell.edu/stories/2021/03/bald-eagle-count-quadruples-thanks-part-ebird-data-boost">quadrupled</a> in the lower 48 states between 2009 and 2021, reaching about 316,000, the current findings on the dangers of lead poisoning raise alarms among scientists and conservationists.



“Hopefully, this report will add information that compels hunters, as conservationists, to think about their ammunition choices,” said Professor Schuler. In her view, a better alternative would be the use of copper-based ammunition.



Bald eagles are not the only species endangered by these hunting practices. Trail cameras have repeatedly shown that owls, crows, bears, foxes, coyotes, or <a href="https://www.earth.com/news/fisher-populations-will-struggle-to-survive-increasing-wildfires/">fishers </a>also scavenge the remains left by hunters.



“We haven’t collected data on these other species in the same way that we pay attention to eagles," said Professor Schuler. "We’re putting eagles out there as a poster species for this issue, but they’re not the only ones being impacted."



The study is published in the <a href="https://dx.doi.org/10.1002/jwmg.22177">Journal of Wildlife Management</a>.&nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Bald eagles are threatened by poisoning from lead ammunition

Bald eagle populations have steadily increased in recent decades, after...

The world's largest fish breeding area has been discovered in the Antarctic Weddell Sea. Using an advanced underwater camera system, a team of scientists led by the <a href="https://www.awi.de/en/">Alfred Wegener Institute</a> found what is estimated to be 60 million icefish nests near the Filchner Ice Shelf.&nbsp;



The colony represents a fish biomass of more than 60,000 tons, or over 135 million pounds. According to the study authors, their findings provide support for the establishment of a Marine Protected Area in the Atlantic sector of the Southern Ocean.&nbsp;



The researchers towed a camera system and photographed the massive breeding site. The photographs suggest that the icefish nests cover about 240 square kilometers, which is roughly the size of the island of Malta.&nbsp;



"The idea that such a huge breeding area of icefish in the Weddell Sea was previously undiscovered is totally fascinating," said study lead author Autun Purser, a deep-sea biologist at the AWI Helmholtz Centre for Polar and Marine Research.



Since the early 1980s, AWI scientists have been exploring the Weddell Sea with Polarstern, a German research icebreaker. Prior to this study, the team had only detected small clusters of nests.



The observations were made using the Ocean Floor Observation and Bathymetry System (OFOBS), a camera sledge built to survey the ocean floor in extreme conditions.&nbsp;



"After the spectacular discovery of the many fish nests, we thought about a strategy on board to find out how large the breeding area was - there was literally no end in sight. The nests are three quarters of a metre in diameter - so they are much larger than the structures and creatures, some of which are only centimeters in size, that we normally detect with the OFOBS system," said Purser.&nbsp;



"So, we were able to increase the height above ground to about three metres and the towing speed to a maximum of three knots, thus multiplying the area investigated. We covered an area of 45,600 square metres and counted an incredible 16,160 fish nests on the photo and video footage."



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/Low-Res_20210216_FishnestsWeddellSea_PS124_AWI_OFOBS_Team_003.jpg.png" alt="" class="wp-image-1900975"/><figcaption>Image Credit: AWI OFOBS Team</figcaption></figure>



Based on the images, the round fish nests were about 15 centimeters deep and 75 centimeters in diameter, and were clearly distinguishable from the muddy seafloor.



The team found several types of nests, including active nests that contained an average of 1,700 eggs. About 75 percent of the time, these active nests were guarded by an adult icefish. Overall, about 100,000 nests were captured on film, and many of them were unused.&nbsp;



Further research is needed, but the experts speculate that the colony is an important source of food for predators such as Weddell seals.



“A great many Weddell seals spend much of their time in close proximity to the fish nests,” said Purser. “We know this from historical tracking data and fresh tracking data from our cruise. The nests are exactly where the warmer water is upwelling. These facts may be coincidence, and more work is needed, but the recorded seal data show seals do indeed dive to the depths of the fish nests, so may well be dining on these fish."



The study is published in the journal <a href="https://www.cell.com/current-biology/home">Current Biology</a>.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Scientists have found the world's largest fish breeding site

The world's largest fish breeding area has been discovered in...

Newborn dairy calves are most often housed separately from each other after being removed from their mothers. Farmers state that keeping calves separate reduces the risk of <a href="https://www.earth.com/news/fast-food-diets-linked-to-rise-in-autoimmune-diseases/">disease</a> transmission, prevents the calves from suckling on one another, and enables more careful feeding and monitoring of individual calves during the first weeks or months of their lives.&nbsp;



Approximately 75 percent and 60 percent of preweaning dairy calves in the United States and Europe, respectively, are housed individually, despite the growing criticisms of this practice in terms of its impacts on calf behavior, welfare and health. The alternative of raising young calves in social groups has, however, received increasing support from scientific quarters and from the concerned public.&nbsp;



A new study published this week in <a href="https://www.jdscommun.org/">JDS Communications</a>, the journal of the American Dairy Science Association, quantifies the motivation of socially naive calves to seek companionship with another calf, when they have the choice.&nbsp;



“Past behavioral studies have indicated that lack of social interaction can negatively affect calves’ feed intake, social skills, coping abilities, and cognitive performance,” stated lead investigator Dr. Marina von Keyserlingk. “However, previous studies on social motivation among young cattle have not addressed the first six to eight weeks of life, when individual housing is the most common.”&nbsp;



In the study, 10 male Holstein calves (average age 5.4 days) were separated into pairs, one of each pair being termed the “subject” while the other was the “partner.” Each pair was housed in a facility consisting of a central home pen with adjacent pens to the left and the right. Pens were separated by one-way push-gates made of plexiglass sheets. After the morning feed of milk, the subject was placed in the central pen, the partner was randomly allocated (by coin toss) to one of the side pens, and the other side pen was left empty.



For 15 days, the calves were checked twice daily at the time of milk feeding (approximately 0800 and 1600 h). At that time, the subject would be found in the central pen, or could have pushed his way through the door into a side pen, either the one containing the partner calf, or the one that was empty. The push-gates swung closed after a calf passed through and would not open in the opposite direction. The subject was returned to the central pen at feeding time.



Each time the subject had pushed his way into one of the side pens, the weight of the gate into that side pen would be increased. This meant that gates were relatively light to push open at the start of the study, when calves were learning the system, but they became more difficult to push as the experiment continued. The maximum weight pushed and number of pushes by each subject calf over the 15-day trial were recorded separately for the two side pens.&nbsp;



“Each time the test calf pushed open the gate to access a side pen, he would remain in it until the next milk feeding (approximately 0800 and 1600 h), at which time he was returned to the central home pen,” explained Dr. von Keyserlingk. “After each successful pushing event, additional weight was added to the gate – initially a small amount, then incrementally higher.”&nbsp;



With this design, the researchers were able to quantify the motivation of the young calves to access company in the form of the partner calf. No prior training of the subject calf was necessary, and the calves learned quickly how to open the gates after first coincidentally pushing a gate open as they investigated it.



The researchers found that, of the 10 calves tested, 8 pushed more weight for the pen on the social side, 1 pushed more for the empty side, and 1 pushed the same weight for both sides. Over the 15-day trial, calves pushed gates weighing, on average 1.0 kg more in order to access the social pen. All calves but one opened a gate on the first day of testing, with the remaining calf pushing a gate open for the first time on the third day.&nbsp;



The results indicate that young calves are motivated to seek full social contact, even when they have to work harder to achieve this. They are clearly social animals and derive benefit from contact with other calves.&nbsp;



A recent U.S. survey found that approximately half the participants considered individual housing of calves unacceptable, often mentioning the lack of socialization as a major issue. The results of the current study add to the body of research evidence that highlights the importance of social contact for calves.&nbsp;



The authors also note that the testing method used in this study did not require training, but calves quickly learned to use the gates on their own, suggesting that this task could be readily used to assess spontaneous motivation in other situations as well.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Dairy calves prefer to be housed with a companion

Newborn dairy calves are most often housed separately from each...

A new study published in the journal <a href="https://www.pnas.org/content/119/2/e2023340118">Proceedings of the National Academy of Sciences</a> has found that the mechanisms behind the sense of <a href="https://www.earth.com/news/how-can-a-smell-transport-us-to-another-place/">smell</a> may be far simpler than previously thought. By studying the olfactory sense of locusts, a research team led by the <a href="https://wustl.edu/">Washington University in St. Louis</a> mapped the neuronal underpinnings behind invariant odor recognition.



“The smell of coffee is the same whether it is smelled in a coffee shop or grocery shop (different backgrounds), on a hot day or a cold day (different ambient conditions), after lunch or dinner (different temporal contexts), or using a deep inhalation or normal inhalation (different stimulus dynamics),” explained the study authors.



“This feat of pattern recognition that is still difficult to achieve in artificial chemical sensing systems is performed by most sensory systems for their survival. How is this capability achieved?”



In order to answer this question, the scientists first trained locusts to associate a specific odor with some of their favorite foods, such as blades of grass. After staying without food for a day, the locusts were exposed to a puff of odor (hexanol or isoamyl acetate), then given a blade of grass. After only six such presentations, the locusts learned to open their palps (the sensory appendages close to its mouth) in expectation of food immediately after smelling the “training odorant.”



The researchers then mapped which neurons were activated when the locusts were exposed to the odorant under different environmental conditions, such as in conjunction to other smells, in humid or dry conditions, or when the locusts were fully fed or starving. Even though the locusts opened their palps every time, different patterns of neurons were activated, depending upon each specific context.



"The neural responses were highly variable," said study senior author Baranidharan Raman, a professor of Biomedical Engineering at Washington University. "That seemed to be at odds with what the locusts were doing, behaviorally."



To understand how variable neural responses produced stable behavior, Professor Raman and his colleagues used a machine-learning algorithm that exploited two functional types of neurons: “ON neurons,” which were activated when an odorant was present, and “OFF neurons,” which fired only after the odor presentation had ended.&nbsp;



"You can think of the ON neurons as conveying 'evidence for' an odor being present, and OFF neurons as 'evidence against' that odor being present," explained Professor Raman.&nbsp;



To recognize the presence of an odorant, the scientists simply needed to add evidence for the odorant being present (add the spikes across all ON neurons), and subtract evidence against the odorant being present (add the spikes across all OFF neurons). If the result was above a certain threshold, the machine learning algorithm would reliably predict that the locust smelled the odor and opened its palps.



“We were surprised to find that this simple approach is all that was needed to robustly recognize an odorant,” Professor Raman concluded.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Locusts have a surprisingly simple way of sensing smells

A new study published in the journal Proceedings of the...

species in Cladopathidae