Phagodrilus johnsoni

Although fever is a crucial response that helps organisms combat infections, it has a rather high cost in terms of energy expenditure. For this reason, through a process called “regulated hypothermia,” mammals and birds sometimes lower their temperature instead of raising it when conditions are unfavorable for the production of a fever, postponing the fight against <a href="https://www.earth.com/news/pigs-are-highly-resistant-to-sars-cov-2-infection/">infection</a> until energy is once more abundant. A new study led by the <a href="https://www.international.unesp.br/">São Paulo State University</a> (UNESP) in Brazil has described how regulated hypothermia can help chicks tolerate infection and save energy.



In a previous <a href="https://physoc.onlinelibrary.wiley.com/doi/10.1113/JP281385">study</a>, the UNESP scientists have already shown that regulated hypothermia – a process initially described in mammals – also existed in birds. This suggests that the strategy may have been inherited from a distant ancestor common to both mammals and birds, or that it developed independently in the two groups. In the present study, scientists shed more light on how this process functions in broiler chicks.



“This time we infected broiler chicks with a large dose of a lipopolysaccharide from the cell walls of a bacteria to simulate infection without actually causing disease. We then measured how they coped with infection in four different scenarios: when they were warm and well-fed, cold and well-fed, warm and hungry, or cold and hungry,” said&nbsp;study lead author Lara do Amaral Silva, a postdoctoral fellow at the <a href="https://www.uncg.edu/">University of North Carolina at Greensboro</a>.



While a fever appeared in the warm and well-fed chicks about three hours after they were infected, the body temperature of cold and hungry chicks fell 2°C in the first hour after infection and then rose gradually. However, even six hours after the infection, their temperature was still 0.5°C lower than normal. For the other two groups of chicks, the results lay between these two extremes.



“When the cold fasting chicks were infected, they directed more blood to the skin and panted to let more heat leave their bodies. They were clearly keeping themselves cool, very probably in order to save energy while prioritizing maintenance of vital functions over fighting the infection,” said study senior author&nbsp;Kênia Cardoso Bícego, an expert in Comparative Physiology at UNESP.



In order to clarify whether the cold and hungry chicks were still able to raise their metabolic rates and produce fever, the scientists injected them with a drug that increases metabolism, which would theoretically provide them with enough energy to raise their temperatures. However, the chicks continued to actively seek to lose heat, showing that inhibition of fever was regulated by their organism instead of being a failure of their immune systems.



“The results underscore the conclusion that a drop in temperature during severe infection isn’t a collapse of the organism, as has been argued. On the contrary, it’s an energy-saving response, given that raising the body’s temperature requires a great deal of energy. In addition, lowering body temperature was prioritized when the chicks had to cope with other challenges, such as cold and hunger,” Professor Bícego concluded.



The study is published in the <a href="http://dx.doi.org/10.1242/jeb.243115">Journal of Experimental Biology</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

Regulated hypothermia helps chicks overcome infection

Although fever is a crucial response that helps organisms combat...

A new study led by the <a href="https://www.ucdavis.edu/">University of California, Davis</a> has found that the brains of Egyptian fruit bats (Rousettus aegyptiacus) are highly specialized for echolocation and flight, with motor areas of the cerebral cortex that are involved in sonar production and wing control. While previous theories of motor cortex organization have assumed that muscles are represented individually in the motor cortex, this study has found clear evidence that cortical <a href="https://www.earth.com/news/headbutting-animals-can-suffer-from-traumatic-brain-injuries/">brain</a> areas represent common synergies of muscles across diverse body regions rather than individual muscles.



Egyptian fruit bats are unusual among bats because they use their tongue rather than larynx to echolocate. Thus, they have precise motor control of their tongues and are able to aim sonar beams in various directions by manipulating their tongues within their mouths, without needing to move their heads.&nbsp;



By using electrodes to stimulate different areas of the motor cortex in anesthetized bats, the scientists discovered that their motor cortex has an unusually large area representing tongue movements, with over 40 percent of the sensory and motor cortex producing tongue movements – far more than in other species, such as rodents or primates.&nbsp;



Through similar methods, the researchers have also investigated how these bats’ brains organize their flight. Since a bat’s wing is composed of membranes spreading across its forelimbs, hindlimbs, and tail, moving any of these body parts can affect wing shape and consequently change the path of flight.&nbsp;



The scientists found that, while very few areas of the bats’ motor cortex represented forelimb movement alone, most of the cortex represented synergistic movements that involved both forelimbs and hindlimbs. These findings reflect the fact that when bats fly, the power for wing movement comes from shoulder muscles, while the fine adjustments that are necessary for flying emerge from complex coordinated movements of both shoulder and hindlimb muscles.&nbsp;



However, some areas of the cortex did seem to produce movements of the hindlimb muscles alone. These brain regions are likely involved in bats’ locomotor behaviors, such as “walking” around in trees by gripping branches with their hindlimbs.



Study senior author Leah Krubitzer is a neuroscientist at UC Davis studying the brain organization of a wide variety of mammals, including rodents, primates, opossums, and tree shrews. According to Krubitzer, comparing the brains of various animals could shed more light on the structure and functioning of the human brain too. “When we can look across species, it becomes a really powerful approach for making extrapolations to the human condition,” she concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1016/j.cub.2022.04.094">Current Biology</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

Bats’ brains are highly specialized for flight

A new study led by the University of California, Davis...

Anyone who’s heard of the problems in the Everglades probably knows that released <a href="https://www.earth.com/news/praying-mantises-are-becoming-more-popular-as-pets/">pets</a> can become invasive. Non-native plants and animals often outcompete native wildlife and harm ecosystems. Unfortunately, releasing a pet into the wild can mean hurting other wild creatures.&nbsp;



Unsurprisingly, fish are one of the most commonly released pets. In fact, released pets make up one third of aquatic invasive species. Goldfish have been domesticated for thousands of years and are extremely popular. These fish have established non-native populations all over the planet.&nbsp;



Now, a study published in the journal <a href="https://neobiota.pensoft.net/">NeoBiota</a> looks at goldfish and another pet fish, the white cloud mountain minnow in Northern Ireland. The researchers developed new techniques for assessing the potential risks and impacts of invasive pet species.&nbsp;



Goldfish, in particular, appeared to be dangerous to the native ecology of Ireland. Goldfish ate more food than either the white cloud mountain minnow or native Irish fishes. Goldfish were also brave, a trait thought to promote invasive behavior.&nbsp;



“Our research suggests that goldfish pose a triple threat. Not only are they readily available, but they combine insatiable appetites with bold behavior," explained study lead author Dr. James Dickey from Queen’s University Belfast.



"While northern European climates are often a barrier to non-native species surviving in the wild, goldfish are known to be tolerant to such conditions, and could pose a real threat to native biodiversity in rivers and lakes, eating up the resources that other species depend on.”



The scientists hope that they not only show that goldfish are potentially dangerous to ecology, but also help others assess risks of goldfish and other pets in other locations in the world.&nbsp;



“Our research highlights that goldfish are high risk, but we hope that the methods developed here can be used to assess others in the pet trade across Ireland and further afield," said Dr. Dickey.



"Readily available species are most likely to be released, so limiting the availability of potentially impactful ones, alongside better education of pet owners, is a solution to preventing damaging invaders establishing in the future.”



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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

Releasing goldfish is a threat to native wildlife

Anyone who’s heard of the problems in the Everglades probably...

<a href="https://www.earth.com/news/showing-signs-of-stress-could-make-you-more-likeable/">Stress</a> is a widespread phenomenon among humans, usually occurring when we feel threatened or overwhelmed. Humans often communicate to others that they are stressed through their behavior or physiological changes. Thus, stress can also convey information, and even be useful in certain situations. 



However, since stress can be easily transmitted from one person to another, it frequently leads to dangerous situations, such as mass panics. Now, a research team led by the <a href="https://www.uni-konstanz.de/en/">University of Konstanz</a> has found that the transmission of stress can also be observed across various animal species.&nbsp;



“It has been repeatedly shown that stress can be transmitted from one human to another,” said study lead author Hanja Brandl, a behavioral ecologist at the Center for the Advanced Study of Collective Behavior at the University of Konstanz. “Often a similarly strong physiological response is triggered, even though you have never experienced the stress yourself.”



As most animals spend at least parts of their lives associating socially with their conspecifics, stress is also transmitted among them. “Other animals in the group can be just as stressed as the friend who experienced something bad. Stress is evolutionarily deeply rooted and the process is similar in all vertebrates,” Dr. Brandl explained.



According to the researchers, wild animals are primarily stressed by naturally occurring threats, such as predators. However, human influences can also raise animals’ level of stress. “Increasing changes in the habitat or noise and light pollution also have an impact, as these massively affect the environment of the animals,” said Dr. Brandl.&nbsp;



While animals are usually flexible and can adapt to changing circumstances, when both natural and anthropogenic stressful factors accumulate, stress is exacerbated and is often transmitted through animal collectives, becoming unhealthy for both individual animals and the groups in which they live. “At some point, the stress response – the adaptations that otherwise help animals better escape stressors like predators – no longer gives them a survival advantage.”&nbsp;&nbsp;



Clarifying how the underlying mechanisms of stress work at both the individual and collective level can help scientists find better ways to protect animals. Moreover, understanding the evolutionary roots of stress responses could also shed more light on how humans experience such phenomena, and open ways for mitigating the negative impact stress often has on health.



The study is published in the journal <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2021.2158#d1e853">Proceedings of the Royal Society B</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

Stress gives animals a survival advantage, but only to a point

Stress is a widespread phenomenon among humans, usually occurring when...

The <a href="https://www.cabi.org/products-and-services/one-health-resources-cabi/one-health-journal-cabi/">CABI One Health</a> journal has published a commentary calling on government and experts to “recognize the importance of animal welfare for sustainable development, and to aspire to harm animals less and benefit them more as part of sustainable development governance.”



This commentary comes ahead of the UN Stockholm+50 Conference on June 2-3, 2022. The conference will include a number of environmental proposals and suggestions to address <a href="https://www.earth.com/news/climate-change-threatens-the-health-of-billions-of-people/">climate change</a>.&nbsp;



The commentary calls attention to the fact that animal welfare has not been considered since the UN Conference on the Human Environment began 50 years ago. To be clear, the 2030 Agenda for Sustainable Development may include protecting species as a whole, but ideas on how to protect the welfare of those animals were not considered. The commentators are perplexed as to why animal welfare has not been a part of the discussion.



“Human, animal, and environmental health are linked,” explained Jeff Sebo of New York University, a lead author of the commentary. “Governments need to take steps to include animals in sustainable development governance for the sake of human and non-human animals alike.”



To see an example of the link between the environment, humans, and non-human animals, look no further than the industrial animal agriculture complex.



The commentary authors noted that animal agriculture requires more land and water and produces more pollution and waste than plant-based foods. And, of course, the industry is the leading cause of climate change.



We can also consider the current outbreaks of bird flu which have led to the deaths of millions of birds and can be attributed to overcrowding and the overuse of antibiotics.&nbsp;



Cleo Verkuijl of the Stockholm Environment Institute mentions an even more omnipresent disease caused by a lack of attentiveness to animal welfare. “COVID-19 reminds us that industries like industrial animal agriculture and the wildlife trade not only harm and kill many animals per year but also contribute to global health and environmental threats that imperil us all.”&nbsp;



Over 180 experts have endorsed the commentary as of May 23, 2022. But, its authors encourage more experts and governments to acknowledge the “intrinsic value of animals and consider their interests when making policy decisions that affect them.”&nbsp;



Professor Maria José Hötzel of the Federal University of Santa Catarina emphasizes that “governments cannot afford to wait another 50 years to take this issue seriously.”&nbsp;



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By <a href="mailto:nire518@gmail.com">Erin Moody </a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Animal welfare is essential to sustainable development

The CABI One Health journal has published a commentary calling...

Divers who visit ocean coral <a href="https://www.earth.com/news/without-action-coral-reefs-could-disappear-in-the-next-three-decades/">reefs</a> can hear the sounds of the reef organisms as they go about their daily business of feeding, communicating and moving about. The underwater sounds are reminiscent of static on a poorly-tuned radio, or the tantalizing hiss of eggs and bacon frying in the pan. In fact, when it is teeming with life, a coral reef is one of the noisiest places in the ocean, say scientists.



The characteristic sounds come from many sources, including the rasp of urchin and starfish teeth as they graze against the hard surfaces, shrimps that stun their prey with loud bubbles produced by their pincers, and fish that pluck off bits of coral. Added to these are the distant sounds of dolphins and whales communicating, and the zinging of tiny bubbles of oxygen as they zoom towards the sea surface. In fact, the more complex the soundscape, the more healthy the reef.&nbsp;



For researchers, sound recordings of these underwater activities could be an effective and economical way to assess the health of vulnerable reefs, since reefs that degrade tend to become quieter and less diverse in their acoustic characteristics. This type of monitoring offers a long-term and nonintrusive way to assess the state of reefs around the world, which are threatened by the effects of fishing, pollution and climate change.&nbsp;



At the upcoming 182nd Meeting of the <a href="https://acousticalsociety.org/">Acoustical Society of America</a>, Lauren Freeman of the U.S. Naval Undersea Warfare Center Newport, will present the results of her experiments using passive acoustic monitoring to evaluate the health of coral reefs. Her presentation, "Coral Reef and Temperate Coastal Soundscape Features Evident in Directional and Omnidirectional Passive Acoustic Time Series," will take place on May 25th.



Freeman and her team used an acoustic array to monitor reefs off the coast of Hawaii, with the premise that degraded coral reefs become unsuitable for marine organisms and, as they abandon the communities, the soundscapes become less rich and diverse. In degraded communities, there tend to be fewer fish calls and a greater preponderance of high frequency noise from algae photosynthesizing and releasing bubbles of oxygen, which ring out as they rise through the water.



“There is a natural competition between corals and macroalgae on all coral reefs. In most cases with a dying or degraded reef, the macroalgae is winning and covers a lot more of the surface,” said Freeman. “On a pristine reef, you would see very little macroalgae, and a lot of herbivorous fish that help eat the macroalgae.”&nbsp;



Freeman and her team compared the results from Hawaii to similar data from Bermuda and New England. Interestingly, Hawaii and Bermuda both showed a characteristic reef evening chorus, where the sound levels increased immediately prior to sunset. The New England reef underwent similar changes near dusk. &nbsp;&nbsp;



“Almost every time I conduct an experiment, we learn more about the complexities and intricacies of ambient biological soundscapes,” said Freeman. “It's so exciting to continue to discover more about ocean ecosystems.”



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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

Healthy coral reefs crackle with the sounds of busy inhabitants

Divers who visit ocean coral reefs can hear the sounds...

For decades, paleontologists have debated whether <a href="https://www.earth.com/news/the-dinosaurs-died-in-the-springtime/">dinosaurs</a> were cold-blooded, like reptiles, or warm-blooded, like mammals or birds. Since cold- and warm-bloodedness are closely related to animals’ metabolic rates – how quickly their metabolism could transform oxygen into energy - clarifying this issue could shed more light on how active dinosaurs were and what their daily life looked like.&nbsp;



A research team that included scientists from the <a href="https://www.fieldmuseum.org/">Field Museum</a> in Chicago has now developed a new method for studying dinosaurs’ metabolic rates by using clues in their bones which indicated how much oxygen they breathed. By using this groundbreaking technique, the experts found that most of the dinosaurs, such as the theropods or sauropods (the so-called ornithischians, or bird-hipped dinosaurs), were warm-blooded, while saurischian (lizard-hipped) species, such as the Triceratops and Stegosaurus, were cold-blooded. 



“This is really exciting for us as paleontologists - the question of whether dinosaurs were warm- or cold-blooded is one of the oldest questions in paleontology, and now we think we have a consensus, that most dinosaurs were warm-blooded,” said study lead author Jasmina Wiemann, a postdoctoral fellow at the <a href="https://www.caltech.edu/">California Institute of Technology</a>.



When animals breathe, side products from this activity react with proteins, sugars, and lipids, leaving behind molecular “waste” which is extremely stable and water-insoluble. This waste is preserved during the fossilization process, leaving behind a reliable record of how much oxygen a dinosaur was breathing in, and thus, its metabolic rate.&nbsp;



The researchers analyzed the femurs of 55 different groups of animals, including dinosaurs and some of their relatives such as the pterosaurs or plesiosaurs, as well as modern birds, mammals, and lizards. By comparing the amount of breathing-related molecular byproducts with the known metabolic rates of the living animals, they found that dinosaurs’ metabolic rates were generally high, suggesting that they were warm- or even hot-blooded. For instance, bird-hipped dinosaurs – including predators such as Tyrannosaurus Rex or Velociraptor, as well as giant, long-necked herbivores such as Brachiosaurus – had extremely high metabolic rates, comparable to those of modern birds, and much higher than mammals. However, most of the lizard-hipped dinosaurs, such as Stegosaurus or Triceratops, had low metabolic rates similar to those of modern reptiles.



These findings could over fundamentally new insights on how various dinosaurs lived. “Dinosaurs with lower metabolic rates would have been, to some extent, dependent on external temperatures,” said Wiemann. “Lizards and turtles sit in the sun and bask, and we may have to consider similar ‘behavioral’ thermoregulation in ornithischians with exceptionally low metabolic rates. Cold-blooded dinosaurs also might have had to migrate to warmer climates during the cold season, and climate may have been a selective factor for where some of these dinosaurs could live.”&nbsp;&nbsp;



On the other hand, hot-blooded creatures were likely more active and needed to eat a lot. “The hot-blooded giant sauropods were herbivores, and it would take a lot of plant matter to feed this metabolic system. They had very efficient digestive systems, and since they were so big, it probably was more of a problem for them to cool down than to heat up.”



“This new study adds a fundamental piece of the puzzle in understanding the evolution of physiology in deep time and complements previous proxies used to investigate these questions,” concluded study co-author Matteo Fabbri, a postdoctoral fellow at the Field Museum. “We can now infer body temperature through isotopes, growth strategies through osteohistology, and metabolic rates through chemical proxies.”



The study is published in the journal <a href="https://dx.doi.org/10.1038/s41586-022-04770-6">Nature</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

Most of the dinosaurs were warm-blooded

For decades, paleontologists have debated whether dinosaurs were cold-blooded, like...

Phagodrilus johnsoni

Taxonomic tree: