Tropical islands without rats have healthier coral reefs
An international team of scientists led by Lancaster University is reporting that rats must be eliminated on many tropical islands in an effort to protect coral reefs. Invasive rats are killing off seabirds in large numbers, and the researchers have identified previously undetermined consequences for the coral reefs that surround and protect the islands.
While it has been documented that invasive predators such as rats have annihilated seabird populations across most tropical islands, the impact that this was having on coral reefs was not known prior to this study.
The team investigated the health of tropical ecosystems in the northern reefs of the Chagos Archipelago.
“Seabirds are crucial to these kinds of islands because they are able to fly to highly productive areas of open ocean to feed,” said study lead author Professor Nick Graham.
“They then return to their island homes where they roost and breed, depositing guano – or bird droppings – on the soil. This guano is rich in the nutrients, nitrogen and phosphorus. Until now, we didn’t know to what extent this made a difference to adjacent coral reefs.”
Located in the central region of the Indian Ocean, the Chagos islands were ideal for this study because some of the islands are infested with black rats, while others are completely free of rats. The researchers compared the ecosystems surrounding six islands with rats and six rat-free islands.
The study revealed severe ecological damage caused by the rats that extended beyond the islands and into the sea. The experts found that islands without rats had substantially more seabirds as well as nitrogen in the soil. In the ocean, the increased nitrogen benefited macroalgae, filter-feeding sponges, turf algae, and fish on the adjacent coral reefs.
Fish were found to be about 50 percent more abundant in the waters adjacent to rat-free islands. In addition, the consumption of algae and dead coral, a replenishing process known as grazing, was over three times higher in the sea adjacent to islands that were free of rats.
“The results of this study are clear. Rat eradication should be a high conservation priority on oceanic islands,” said Professor Graham.
“Getting rid of the rats would be likely to benefit terrestrial ecosystems and enhance coral reef productivity and functioning by restoring seabird derived nutrient subsidies from large areas of ocean. It could tip the balance for the future survival of these reefs and their ecosystems.”
The study is published in the journal Nature.
Two new species of fuzzy yellow bats identified in Kenya
The relatively small country of Kenya has 110 species of bats, many of which have additional subspecies. While studying the evolutionary history of yellow house bats, or Scotophilus, researchers have discovered two previously unknown species.
Study lead author Terry Demos is a Postdoctoral Fellow at Chicago’s Field Museum.
“They’re cute. They look a lot like the bats you see in Chicago but they’re this great yellow color,” said Demos. Yellow bats vary in size and other characteristics, but they are generally small with soft fur.
Yellow bats often take up residence in the cracks and corners of homes in Kenya. “These are bats that live with people – they don’t call them house bats for nothing,” said study co-author Bruce Patterson.
Even though they can fly, bats prefer to stay in a specific region and do not fly too far to find a home. This contributes to the large amount of diversity that is found in bats across Africa.
The team used advanced genetic analysis techniques to distinguish between different species of yellow bats. By comparing all of the DNA sequences, the researchers were able to develop a chart that shows relationships between the species.
The chart, which resembled a family tree, predicted at least two new species of bats.
“These new species are unknown to science,” said Demos. “There was no reason to expect that we’d find two new species there.”
“It’s cool because it says there’s a chapter of evolution that no one’s stumbled across before,” added Patterson.
In Kenya and other regions across Africa, there are many other species yet to be discovered.
“Africa is understudied, and its biodiversity is underestimated, and it’s critical because there are threats to its biodiversity,” said Demos.
In particular, understanding more about bats can help conservation and local farming efforts, according to Demos. This research provides a framework that can be used to explore bat species in other regions.
“No interesting biological questions are ever fully answered, and progress towards answering them invariably opens up a variety of others,” said Demos.
The study is published in the journal Frontiers in Ecology and Evolution.
African fish uses electrical signals to navigate murky waters
The elephant-nose fish – scientific name Gnathonemus petersii – uses electrical signals to navigate through the water and find food, which is a particularly useful skill given that it lives in murky African rivers. Since us humans don’t use electricity to find our way in the world, this system can be a bit of a mystery to scientists. But researchers at Columbia University have just found a very cool quirk in this fish’s electric navigation system.
In the journal Neuron, the scientists have published evidence that the elephant-nose fish’s ability to “see” an “electrical image” of its surroundings requires it to filter out the fish’s own electrical interference.
This fish has two specialized systems to help it sense its surroundings. The passive system is responsible for the tiny electric signatures of everything that lives in its habitat, while an active system voluntarily emits quick pulses of electricity. These electrical pulses are used to both communicate with other fish and allow the individual to sense its environment by producing an electrical image.
“The fish’s own electrical pulses cause large neural responses that interfere with the passive system,” says Nathanial Sawtell, a neuroscientist at Columbia University. “Our work shows how changes in neural connections produce negative images to cancel out this interference.”
Earlier studies have postulated that this fish is able to generate these negative images, but this study presents the first evidence of this theory and the functional importance of this trait.
“We needed to determine whether being able to predict its own electrical signals would help the fish better detect environmental cues,” says Sawtell. “So using both neural recordings and behavioral experiments, we showed that these predictions known as negative images actually do help the fish sense external signals related to hunting prey.”
By exposing the fish to a drug that interfered with the formation of negative images, the researchers found that they essentially blinded the fish to external electrical signals.
“An important part of this work has been the integration of experimental and theoretical approaches to understanding neural circuits,” explains Sawtell. “From here, we’re trying to take the lessons we’ve learned from the electric fish and apply them to related systems, including the mammalian cerebellum and auditory system.”
How to tell if a horse is happy? Listen to the snorts
If you spend a lot of time around domesticated animals, you might begin to notice certain behavioral signals they give depending on their mood. When happy, a dog may wag its tail or a cat will begin to purr – those signals are obvious. But what about horses? How does a horse get across to us humans that it’s in a good mood?
Anecdotal reports have pointed towards the prevalence of horses producing “snorts” – that is, expelling air through their nostrils – when they are in positive situations.
Given this knowledge, Mathilde Stomp of the Université de Rennes, France, and her colleagues wanted to see if they could determine this experimentally. They evaluated snort production by 48 horses that live in either restricted conditions (riding school horses that spent a lot of time in individual stalls) or naturalistic conditions (stable groups of horses always in pasture).
The researchers published their results in PLOS ONE, reporting that snort production was associated with positive situations and a horse’s positive internal state – which is indicated by their ears positioned forward or sideways. Riding school horses produced twice as many snorts in pasture compared to when they were in their stalls. Furthermore, horses that were always in pasture had significantly higher snort production than riding school horses in comparable contexts.
“These results provide a potential important tool as snorts appear as a possible reliable indicator of positive emotions which could help identify situations appreciated by horses,” says Stomp.
Our ability to assess positive emotions in animals is an important step in improving animal welfare. Simply put, if a horse is frequently snorting, it’s likely that it has a positive internal state and is happy with its current situation. Indicators such as this can help owners and breeders better suit a horse’s living situation to what makes the animal the most content.
Salamanders may be surprisingly resistant to climate change
The Appalachian Mountains are a global hotspot for salamanders, and ten percent of the world’s salamander species reside in the Southern Appalachian region.
But climate change could make the region inhospitable for salamanders by 2080, leading to an increased risk of extinction for the amphibians and decreasing the rich biodiversity of the area.
However, a new study found that salamander resilience and adaptability, also known as plasticity, has been underestimated by previous research.
The study was conducted by researchers from Clemson University and published in the journal Science Advances.
Salamanders have a great ability to adapt to their environment which led Eric Riddell and Michael Sears, the study’s lead authors, to conclude that salamander plasticity will reduce potential extinction risk up to 72 percent.
Unlike previous studies, the researchers took into account salamander plasticity and how salamanders respond and adapt to stressful temperatures.
“This is one of the first papers that has exclusively looked at plasticity in this sense,” said Sears. “We’re telling you that our new predictions are nowhere near as dire as earlier predictions. In this part of the world, this is a particularly big deal. We can now say more accurately what might occur if climatic conditions continue to deteriorate.”
Sears and Riddell searched for salamanders in North Carolina and estimated the amphibian rough biomass in the area.
The exact number of salamanders in the Appalachian is not known, but in just one square mile of forest, its estimated that you could find a combined salamander biomass of 2500 to 5000 pounds.
Because salamanders are mostly nocturnal many people are probably unaware of just the sheer amount of lizard-like amphibians in the area.
Understanding the threats that climate change poses to salamanders and their habitats is important not just because of the risk of biodiversity loss, but also because of the crucial role that salamanders play in the local ecosystem.
Some salamanders are lungless and absorb oxygen through their moist skin.
This is why previous estimates were concerned about the potential risks of climate change as warmer temperatures would increase aridity in the area making it harder for certain salamanders to absorb the oxygen they need.
However, due to how long salamanders have been in the area, Sears and Riddell feel that their resilience has been largely underestimated and that when temperatures inevitably increase, salamanders will adapt.
David Wake, a curator of the Museum of Vertebrate Zoology at the University of California, Berkeley who was not involved in the study, agreed with Sears and Riddell’s theory of salamander plasticity.
“During the past 2 million years, the southern Appalachians have experienced some dramatic incidents of climate change,” said Wake. “So, how did the salamanders handle it? And how will they handle the accelerated climate change that most scientists accept as a near certainty? In short, they are able to adjust their physiology much more than we previously thought, and this perhaps accounts for much of their ability to deal with climate change – not by running away, but by using their abilities to adjust through time.”
When the queen bee dies, how do worker bees choose her successor?
For honey bees, everything revolves around the queen, and for good reason. As the only fertile female in the entire colony, she is the mother of all the bees in the hive.
Worker bees, the sterile females, serve the colony any way they can and male drone bees mate with the queen.
But what happens to a caste system so central to its ruling monarch when the queen unexpectedly dies? How do drones and worker bees choose a new queen?
When a queen does die, it’s up to the worker bees to choose a group of larvae to raise as emergency queens, but researchers from North Carolina State University set out to see if the bees purposely choose larvae from their own subfamilies instead of royal larvae.
It would make sense that the bees would choose a larva from their own gene pool because of the natural preference many species have to protect and promote their own genes.
However, the results, published in the journal PLOS Biology, show that this selfish tendency is not present in honey bees and instead, the bees choose the royal larvae.
The researchers compared DNA from 92 workers and 85 emergency queens from six different colonies. Per colony, the researchers estimated 34 to 77 subfamilies, much more than previous research had found.
The emergency queens hailed from extremely rare subfamilies with very few members according to their DNA.
This led the researchers to conclude that in the event of the sudden death of their queen, the worker bees specifically choose larvae from royal subfamilies over their own close relatives.
However, considering how close-knit bees in a hive are, the researchers are not sure how worker bees are able to distinguish royal larvae from others.
“While many of the specific details and mechanisms are still to be determined,” said James Withrow, a lead author of the study. “At this point, we may safely conclude that, while inclusive fitness for nepotism may favor the individual level during emergency queen rearing, that advantage is profoundly overridden by opposing selective forces acting at multiple levels favoring cooperation and altruism.”
The results show that hive mentality overpowers selfish genetic interests.
“While we already knew that honey bee queens mate with a large number of drones to bring genetic diversity into their colonies, this study suggests that many of a queen’s mates are fathering only a tiny fraction of her total offspring,” said Withrow. “But workers are preferentially selecting members of these cryptic subfamilies for rearing into new queens.”
Image Credit: Joseph Milone
Best habitats for bird conservation consider soil and topography
A new study has revealed that the preferences of birds should be considered for the successful restoration of habitats. While previous projects have been primarily focused on plants to identify the needs of sensitive animals, researchers have found that there is more to an ecosystem than just plants that provide birds with what they need.
Clark Winchell of the U.S. Fish and Wildlife Service teamed up with Paul F. Doherty, Jr. of Colorado State University to explore ways of improving the traditional “single-species -oriented” conservation plan. The study was focused on the coastal sagebrush habitat of the California Gnatcatcher.
Using bird survey data, the team discovered that the probability of colonization by gnatcatchers tripled as the ratio of coastal sagebrush increased from 10 to 40 percent. Another strong predictor of occupancy was the amount of openness in the habitat, and the experts found that 30 to 40 percent openness was ideal.
The most suitable habitat for the birds was also influenced by elevation and soil texture. Winchell and Doherty found that lower elevations and loam or sandy loam soils were most preferred, and that the gnatcatchers preferred southern aspects, shallow slopes, and inland areas.
By using a detailed scale for their analysis, the researchers were able to identify very specific areas that are the most suitable for gnatcatchers. This type of thorough research will better inform conservation efforts and lead to successful restoration projects by providing more accurate guidelines.
“Restoration ecologists are generally not gnatcatcher biologists, and vice versa. Sometimes we tend to place restoration projects where land becomes available after political negotiations,” said Winchell. “We may want to consider what is that parcel of land trying to tell us – what does the land want to be, so to speak – versus assuming we can dictate the final outcome for a location.”
“Considering the entire functionality of the surrounding ecosystem, including the physical components, the biological community, and understanding the dynamism of the ecosystem will lead to improved restoration and wildlife management outcomes and our study is one small step in that direction.”
The research is published in the journal The Condor: Ornithological Applications.
Image Credit: A. Fisher
Lost extinctions: When animals die off before science finds them
Certainly the majority of plants, animals, fungi, etc. that have become extinct died long before people, let alone scientists, got around to describing them.
Dinosaurs, the most famous of extinct animals, died off around 65 million years ago, before humans evolved and certainly before Linnaeus invented his way of scientifically classifying organisms. According to PBS, of all the organisms that ever ran, gasped, ate or simply grew in the soil, 99.9% are now extinct.
Oil spills, global climate change, over hunting, and starved feral cats have done a lot of damage, but not nearly that much. The fact is, like every person you now know; every species alive today will someday be dead. Species, like individuals, have lifespans. Just as we don’t use the argument, ‘they were eventually going to die anyway’ to justify the holocaust or school shootings, the rate of modern extinctions is inexcusable. A vast number of modern extinctions are the fault of humans, too.
Most of us are aware of modern extinctions like that of the Dodo, the Passenger Pigeon and the Thylacine. Most of us are also aware of a handful of the myriad of known threatened and endangered species. Most of us have heard of Jane Goodall’s beloved chimpanzee and vaguely know that dolphins and some fish species aren’t doing so well these days. Less of us understand the size of the extinction event we’re tied up in at this very moment. There are so many more insects, amphibians, small mammals and others less charismatic than the Panda that may soon face extinction.
Also, much like an individual human leaves children behind, species often diverge, leaving new species as ancestral ones become extinct. Like many tragedies, there are many that are now dying, unknown and unrecognized, sometimes directly from human causes.
In his book The Secret Knowledge of Water, Craig Childs talks about small, natural desert pools in California and the invertebrates discovered in them:
“They become genetically isolated over thousands, and then millions of years. In 1992, after nearly all of the temporary vernal pools of California were destroyed by human development, researchers went out to catalog those still intact. Of the sixty-seven species of crustaceans found in the remaining pools, thirty had never been documented anywhere on the planet…A quarter of these newly found species were each found in its own pool among the fifty-eight pools studied, meaning there is not much motion between one pool and the next. What was lost in the hundreds of destroyed pools is unknown.”
Imagine species dying off because of human actions and no one even realizing it until after the fact. Perhaps you or I have stepped on one of the last of an exceedingly rare species of ant or swatted an insect thinking it a mosquito and precipitated extinction. The thought is both depressing and awe inspiring in its suggestion of the number of life forms still inhabiting the planet with us.
The Simandou region of Guinea, West Africa is a land of lush and modest mountains covered in tropical forests. The area is considered one of the world’s most biologically rich but also endangered forest habitats. Among mountains rising as high as 5440 feet above sea level, there are caves. One of these caves contained a rare cockroach, Simandoa conserfariam, or the Simandoa Cave Cockroach. The roach seems unremarkable to most, an animal with a smooth, dark grey body with darker heads and orange-ish legs.
What makes these roaches unique is the fate of their cave home. After scientists collected a few of the cave cockroaches, the cave itself was destroyed by a bauxite mining operation. In a weird twist of fate, the cockroach now lives all over the world, fostered in small cages by pet enthusiasts with irregular love for arthropods. You can even buy a roach nymph online for $6.00 in the US.
I’ve explored caves in search of tiny arthropods as a volunteer for projects involving Northern Arizona University and the Denver Museum of Nature and Science. It’s easy for a spider, a millipede or a cricket living in the dark cracks of limestone to elude a researcher. You can spend a week or a month scouring a cave and still find new animals hiding in the dark. Considering the fate of the Simandoa Cave Cockroach, it’s easy to imagine that many species weren’t lucky enough to be carried into captivity before dying off in their native habitats.
Another cockroach known for its ability to glow, mimicking a poisonous click beetle was discovered in Ecuador. Mongabay reported that the roach, Lucihormetica luckae, may already be extinct. In the case of the glowing cockroach, it vanished after 2010 when a volcano erupted near where it was discovered. The cockroach is (or was) the only known example of a land animal using bioluminescence in mimicry.
In animal taxonomy, vertebrates are more well-known than invertebrates. Partly this is because there are fewer vertebrates and they are generally easier to find, partly we understand vertebrates better because we’re biased towards them. Birds are intensively researched, both professionally and by ‘citizen scientist’ birders fascinated by their feathered neighbors. In an article in cell.com, Alexander Lees and Stuart Pimm paint a picture of some of the birds we may have lost in Brazil’s highly endangered Atlantic Forest and elsewhere in the world:
“The recent update of the IUCN Red List has identified 13 more bird species that went extinct after 1500, but before taxonomists could describe them. All of these were island species. We are still documenting the impacts of European explorers —and the rats and cats that came with them — that began centuries ago. We know about some early extinctions from anecdotal evidence, such as eyewitness accounts and drawings… Northeast Brazil has a similar, albeit less certain example: multiple travellers reported an all-black parrot, but no specimen exists…”
If a species of bird can go extinct with little fanfare, without any scientific knowledge, it doesn’t bode well for other less conspicuous organisms.
Nearly the reverse of an organism that goes extinct without being described scientifically is a so-called ‘Lazarus taxon’. A Lazarus taxon is an organism thought to be extinct, sometimes recently and sometimes found only as a fossil but then later is found to actually be still alive.
The classic example of a Lazarus taxon is the coelacanth. The coelacanth can measure up to six feet in length and 200 pounds in weight. The ocean is a vast place to hide for an animal that is dwarfed next to whales, sharks and giant squid. The coelacanth was thought to have died off in the extinction event that took the dinosaurs 65 million years ago until a fisherman caught one off the coast of Madagascar in 1938. A second specimen of coelacanth was found in Indonesia in 1998.
There are a number of animals that were thought to be legend or extinct but turned out to be alive. Gorillas were once thought by westerners to be a native myth, not a real animal. The Golden Bamboo Lemur was thought to be extinct until it was rediscovered.
The fact is, as much as we think we know about the natural world, we’re largely ignorant of even the basics of what organisms are now alive and which are extinct. According to a paper published in PlosOne, an estimated 86% of land species are undescribed by science and 91% of species in the ocean. That leaves an enormous amount of mystery in the world and an enormous amount of potential to destroy life or leave it as it is.
Newly extinct giant seabird may have roamed around the Pacific
The spectacled cormorant was a large-bodied seabird first discovered on Bering Island in the 18th century. It was believed to have only existed on this one island in the northern Pacific Ocean, before being hunted to extinction after Bering Island was colonized by humans in the early 1800s. But scientists have now made an exciting discovery – no, the species is still extinct – but researchers from Kyoto University have found that this bird also resided in Japan almost 120,000 years ago.
In a study published in The Auk: Ornithological Advances, the research team reports that this species underwent a significant range contraction or shift, and that the specimens found on Bering Island are “relicts” of a species that was once more widespread.
“Before our report, there was no evidence that the cormorant lived outside of Bering Island,” says Junya Watanabe of Kyoto University’s Department of Geology and Mineralogy, and first author of the study.
The research team studied bird fossils recovered from Shiriya, identifying 13 bones of the spectacled cormorant from upper Pleistocene deposits, which formed almost 120,000 years ago.
“It became clear that we were seeing a cormorant species much larger than any of the four native species in present-day Japan,” explains co-author Hiroshige Matsuoka. “At first, we thought this might be a new species, but these fossils matched bones of the spectacled cormorant stored at the Smithsonian Institution.”
It is thought that changes in oceanographic conditions could have been responsible for the disappearance of the species in Japan. Previous paleoclimate studies have found that oceanic productivity near Shiriya decreased significantly in the Last Glacial Maximum, which occurred roughly 20,000 years ago. These changes may have dramatically affected the cormorant population.
“The cormorant was a gigantic animal, its large size thought to have been achieved through adaptation to the island-oriented lifestyle on Bering,” says Watanabe. “But our finding suggests that this might not have been the case; after all, it just resided there as a relict. The biological aspects of these animals deserve much more attention.”
The study of extinction events such as this are necessary for us to better understand how natural disturbances affect species – especially in our changing climate. It’s possible that studying the past may ultimately save our future.
Climate change threatens Caribbean reef fish conservation
More than two decades of conservation efforts to protect the endangered Nassau grouper have proven to be successful, as some populations of the species have strengthened across the Caribbean. However, research from the University of Texas at Austin has revealed that this restorative success may be substantially hindered due to climate change.
A team of marine scientists has found that the breeding habitats of the Nassau grouper are projected to decline by 82 percent during this century if climate change is not mitigated.
Acceptable spawning habitats are critical to the survival of these and other reef fish. Nassau groupers, for example, have a narrow temperature range that they can tolerate while spawning.
The experts also found that suitable habitats for non-spawning fish are projected to decline by 46 percent by 2100.
“The effects of climate change could override some of the successes of conservation efforts at local and regional scales,” said study co-author Brad Erisman. “That is, if Nassau grouper no longer migrate to spawn in a particular region because the water is too warm, then protecting spawning sites in that region will be ineffective.”
“Likewise, if the months when spawning occurs in certain regions shifts in response to climate change, then seasonal protection measures in those regions will need to shift accordingly to ensure that spawning is still protected.”
The reproduction success of the Nassau grouper depends on large breeding events, called spawning aggregations, where hundreds to thousands of fish gather in the same region for a few days to mate. These events make the fish easy targets for commercial fishing, and overfishing is what caused the species to become endangered in the first place.
Many countries like the United States have banned the fishing of Nassau grouper, while other nations such as Cuba and the Dominican Republic have restricted fishing during spawning season.
Study co-author Rebecca G. Asch is an assistant professor of Fisheries Biology at East Carolina University.
“To truly understand how climate will impact fishes, we need to know how it will impact the most vulnerable life history stage, spawning,” said Professor Asch. “If this link in the life cycle is jeopardized, the species as a whole will be in jeopardy.”
Grouper are preyed upon by large predators such as sharks, and the health of the marine ecosystem depends on such important components of the food chain.
“The loss of these important, energy-rich events has negative impacts that span entire food webs and ecosystems,” said Erisman.
According to the scientists, the breeding habitat for the Nassau grouper may only be reduced by 30 percent if major steps are taken to slow climate change.
The study is published in the journal Diversity and Distributions.
Image Credit: Alfredo Barroso
Humans are not the only primates to carefully select friends
Many non-human primates live in social groups that revolve around cooperation and the exchange of services much like humans do. Grooming interactions are particularly important in this type of social system because they can be exchanged for some of the most important services, such as food or support during a fight.
Grooming time is limited, so individuals aim to select the best grooming partner from all available candidates. However, the success of the grooming interaction also depends on the audience. For example, if the partner has a friend in the audience, the friend may try to interfere or the partner may choose to leave the grooming session early – wasting the time and effort of the groomer.
Primatologist Alexander Mielke and his team from the Max Planck Institute for Evolutionary Anthropology have studied the social behavior of chimpanzees and sooty mangabeys at Taï National Park. The researchers wanted to know what is taken into account when these animals select a grooming partner, and also whether a nearby audience has any influence on this decision.
As part of the Taï Chimpanzee Project, the researchers collected data in two chimpanzee communities and one mangabey community, analyzing data that had been previously collected to determine the social relationships and ranks of the individuals.
“Choosing a grooming partner from among ten, fifteen possible candidates – some of them friends, high-ranking, or with babies – is a very difficult task indeed,” explained study first author Alexander Mielke. “And yet individuals from both species, chimpanzee and sooty mangabey, chose their partner flexibly.”
“Both mangabeys and chimpanzees actually preferred grooming mothers with babies, something we did not know was the case in chimpanzees. Both species used grooming for reconciliation, and both species groomed their friends more.”
“Most strikingly, in both species grooming choices depended strongly on the social environment. The animals avoided grooming individuals with close friends nearby, possibly because these friends might interrupt the grooming interaction, or because their potential partner might prefer to go and groom these friends.”
Mielke said that individuals also chose partners who were higher-ranking compared to other potential partners, regardless of their overall rank in the community.
“This shows that both species are flexible when it comes to taking a decision, and that individuals use the information they have about all available partners,” he explained. “Yet they also consider the wider social circumstances, and adapt their choice to maximize their own benefit.”
The findings of the study demonstrate that primates are aware of the ranks and social relationships of possible partners, and they also judge individuals flexibly and simultaneously to choose the best option.
“The fact that we found these results in both mangabeys and chimpanzees might indicate that this impressive cognitive feat is more widespread amongst primates than previously known,” said Mielke.
“Grooming is an important part of primate cooperation and choosing the best partner in a specific situation is a vital skill. As in humans, primate social groups consist of many individuals, each with their own status, own objectives, own history.”
“This study gives further evidence that at least mangabeys and chimpanzees are equipped with the cognitive abilities to navigate and thrive in this complex social world.”
The research is published in the journal Royal Society Open Science.
LED lights could save seabirds from getting stuck in fishing nets
An international team of researchers led by the University of Exeter has found that illuminating fishing nets with inexpensive LED lights could cut injuries and deaths to seabirds and marine animals by more than 85 percent.
The experts demonstrated that green, battery-powered LED lights can drastically reduce the amount of birds getting caught in gillnets, which are placed in fixed positions and designed to capture fish by the gills. The investigation was focused on 114 pairs of gillnets in fishing waters off the coast of Peru.
The study revealed that, compared to the nets that were not illuminated, the nets with LED lights caught 85 percent fewer guanay cormorants – a native diving bird that commonly becomes entangled in nets.
A previous study conducted by the same team found that LED lighting also reduced the number of sea turtles caught in fishing nets by 64 percent.
The researchers believe that the lights provide a cheap and reliable method that will dramatically reduce the capture and death of birds and turtles, while essentially having no effect on the amount of fish caught in the nets.
“We are very encouraged by the results from this study,” said lead author Dr. Jeffrey Mangel. “It shows us that we may be able to find cost-effective ways to reduce bycatch of multiple taxa of protected species, and do so while still making it possible for fishers to earn a livelihood.”
Peru’s gillnet fleet is estimated to set at least 100,000 kilometers of net per year, in which thousands of turtles and seabirds will be unintentionally caught as bycatch.
“It is satisfying to see the work coming from our Exeter Marine PhDs leading to such positive impact in the world,” said study co-author Professor Brendan Godley. “We need to find ways for coastal peoples to fish with the least impact on the rest of the biodiversity in their seas.”
The research is published in the journal Royal Society Open Science.
Image Credit: Andrew F Johnson