Tergipes antarcticus

Many bird species migrate large distances across the globe and this movement is integral to their behavior, survival and <a href="https://www.earth.com/news/humpback-whale-reproduction-is-linked-to-krill-abundance/">reproduction</a>. It is important to understand where they go, and when, so that effective conservation actions can be implemented, but it is not possible to track millions of birds as they travel from and to locations all over the world. Migratory birds rely on a predictable series of seasonally and regionally varying resources and are thus susceptible to the global changes in climate and weather patterns that are becoming more common.&nbsp;



Although the movement patterns of individual birds can be deduced from the recapture or recovery of ringed or tagged birds, these techniques are labor intensive and cannot be applied to large numbers of birds. In addition, the weight and shape of tracking devices make them unsuitable for most birds to carry, and they are often too costly to be used on more than a handful of individuals.&nbsp;



However, the world is full of avid birdwatchers who enjoy monitoring and reporting the presence of migratory birds. For example, citizen scientists contribute more than 200&nbsp;million annual bird sightings through eBird, a project managed by the <a href="https://www.birds.cornell.edu/home/">Cornell Lab of Ornithology</a> and international partners.&nbsp;Datasets such as this provide enormous quantities of data on bird presence on a weekly basis, but do not track individuals birds to the end points of their migrations.&nbsp;



In collaboration with computer scientists at the University of Massachusetts Amherst, the&nbsp;<a href="https://www.birds.cornell.edu/home/">Cornell</a> team has now developed a new predictive model using these two different types of data on the movements of migratory birds. In their paper, published in the journal <a href="https://doi.org/10.1111/2041-210X.14052">Methods in Ecology and Evolution</a>,&nbsp;the scientists state that their model, called&nbsp;<a href="https://birdflow-science.github.io/">BirdFlow</a>, is capable of forecasting accurately where a migratory bird will go next, one of the most difficult tasks in biology.&nbsp;



“Humans have been trying to figure out bird migration for a really long time,” said study senior author Professor <a href="https://people.cs.umass.edu/~sheldon/?_gl=1*1j0ouo2*_ga*NjkzNDk1MDI0LjE2NTc3NDI2Mzg.*_ga_21RLS0L7EB*MTY3MzAxOTYwNi4yMzQuMS4xNjczMDIxNTk4LjAuMC4w&amp;_ga=2.230912479.1333256184.1672755734-693495024.1657742638">Dan Sheldon</a>, who is a passionate amateur birder. “But, it’s incredibly difficult to get precise, real-time information on which birds are where, let alone where, exactly, they are going," noted study last author Miguel Fuentes.



There have been many efforts, both previous and ongoing, to tag and track individual birds and, although data from this approach has produced important insights, it cannot give a complete picture that can be used to predict bird movements.&nbsp;



“It’s really hard to understand how an entire species moves across the continent with tracking approaches, because they tell you the routes that some birds caught in specific locations followed, but not how birds in completely different locations might move," said Professor Sheldon.



The new model combines data from tagged and ringed birds with the millions of sightings made by bird enthusiasts around the world through eBird. This is one of the largest biodiversity-related science projects in existence. The database comprises over one billion global bird observations, provided by hundreds of thousands of users. It facilitates state-of-the-art species distribution modeling through the Lab’s&nbsp;<a href="https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fscience.ebird.org%2Fen%2Fstatus-and-trends&amp;data=05%7C01%7Cdrmiller%40umass.edu%7C61e2977796c44819ab0e08daf963edf5%7C7bd08b0b33954dc194bbd0b2e56a497f%7C0%7C0%7C638096504997203259%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000%7C%7C%7C&amp;sdata=kfJj9kfBa%2FElrpfkC3N3AYBDtLOrS6zB41N6bZIEih8%3D&amp;reserved=0">eBird Status &amp; Trends project</a>.&nbsp;



“eBird data is amazing because it shows where birds of a given species are every week across their entire range, but it doesn’t track individuals, so we need to infer what routes individual birds follow to best explain the species-level patterns," explained Professor Sheldon.



The BirdFlow model draws on eBird’s Status &amp; Trends database and its estimates of relative bird abundance, and then runs that information through a probabilistic machine-learning model. This model is tuned with real-time GPS and satellite tracking data so that it can “learn” to predict where individual birds will move next as they migrate. The model is still being perfected, but should be available to scientists within the year, and will eventually also be accessible to the general public.



The researchers tested BirdFlow on 11 species of North American birds - including the American woodcock, wood thrush and Swainson’s hawk - and found that not only did BirdFlow outperform other models for tracking bird migration, bit it accurately predicted migration flows&nbsp;without&nbsp;the real-time GPS and satellite tracking data, which makes BirdFlow a valuable tool for tracking species that may literally fly under the radar.



The new model allows scientists to monitor bird movements and the ways in which these respond to global changes in climate. In North America alone, an estimated three billion birds have been lost in the last half-century, representing nearly a third of the continent’s avifauna. According to the researchers, the&nbsp;BirdFlow&nbsp;framework has the potential to “boost insights gained from direct tracking studies and serve a number of applied functions in conservation, disease surveillance, aviation and public outreach.”



“Birds today are experiencing rapid environmental change, and many species are declining,” said study co-author&nbsp;<a href="https://bvandoren.com/">Benjamin Van Doren</a>. “Using BirdFlow, we can unite different data sources and paint a more complete picture of bird movements, with exciting applications for guiding conservation action.”



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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



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Machine learning may solve the mystery of bird movements

Many bird species migrate large distances across the globe and...

Since 1970, reports of large carnivore attacks on humans have increased. According to a new study published in <a href="http://dx.doi.org/10.1371/journal.pbio.3001946">PLoS Biology</a>, the frequency and context of these attacks depends on socioeconomic and environmental factors.



Giulia Bombieri of MUSE Science Museum in Italy and Vincenzo Penteriani of the National Museum of Natural Science (CSIC) in Spain collected information on reported attacks by 12 species of carnivores between 1970 and 2019.&nbsp;



Using scientific papers, web pages, and news reports, the experts identified 5,089 reported attacks by large carnivores that resulted in injury, of which 32 percent were fatal. Over the 49 year period, the number of reported attacks increased, particularly in lower-income countries.



"Large carnivores have long fascinated human societies and have profound influences on ecosystems. However, their conservation represents one of the greatest challenges of our time, particularly where attacks on humans occur. Where human recreational and/or livelihood activities overlap with large carnivore ranges, conflicts can become particularly serious," wrote the study authors.&nbsp;



The research showed that a staggering 90 percent of attacks in low-income countries took place while individuals were farming, fishing, or grazing livestock. In high-income countries, attacks were most common during recreational activities, such as hiking, camping, or dog-walking. In high income countries, attacks were also less likely to be fatal.



Wild felids (large cats) and canids (dog-like carnivores) were responsible for more predatory attacks, while bears were more likely to attack when surprised, defending cubs, or in food-related interactions. The most fatal attacks occurred in lower-income countries where tigers and lions are present.&nbsp;



The findings suggest that approaches to reduce large carnivore attacks should be tailored to the socioeconomic context.&nbsp;



“When human recreational and/or livelihood activities overlap with large carnivore ranges, it is crucial to understand how to live with species that can pose threats to humans," said Penteriani.



"Factors triggering large carnivore attacks on humans depend on the combination of local socio-economic and ecological factors, which implies that measures to reduce large carnivore attacks must consider the diverse local ecological and social contexts.”



For example, high-income countries can implement education campaigns about high-risk behaviors and how to avoid dangerous encounters. In lower-income countries, zoning changes should expand protective areas and separate humans and livestock from large carnivore habitats.&nbsp;



However, these preventative measures may be challenging to implement as the global population grows.



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By <a href="mailto:katherinebucko@gmail.com">Katherine Bucko</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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Large carnivore attacks are increasing as human impacts expand

Since 1970, reports of large carnivore attacks on humans have...

The <a href="https://www.earth.com/news/puzzling-fossil-has-the-body-of-a-bird-skull-of-a-dinosaur/">skull</a> of a fish that lived around 319 million years ago has recently been analyzed with by scientists from the University of Michigan and the <a href="https://www.birmingham.ac.uk/index.aspx">University of Birmingham</a>. The analysis turned up something unexpected. Within the fossilized skull, the researchers found a discrete, 3D object that could only be the fish’s brain.&nbsp;



This is unusual because soft tissues, such as brains, usually decay when an animal dies, and are seldom fossilized. It has allowed the researchers a window into the neural anatomy and early evolution of the ray-finned fishes, a major group that contains about 30,000 different species, roughly half of all known vertebrate species.&nbsp;



The ancient fossil skull was collected from the roof of a coal mine in Lancashire, UK, around 100 years ago and first described in 1925. At the time, it was identified as belonging to a new species, Coccocephalus wildi, and was put away in a draw in the Manchester Museum. No other fossilized body parts were recovered from the layer of soapstone where the skull was found.&nbsp;



The researchers were not looking for a brain when they used CT-scanning to visualize the structure of the skull. But the unexpected object detected within the skull displayed several features found in vertebrate brains: it was bilaterally symmetrical, it contained hollow spaces similar in appearance to ventricles, and it had multiple filaments extending toward openings in the braincase, comparable in appearance to cranial nerves.&nbsp;



The analysis of the findings has been published in the journal Nature, and the researchers say their discovery sheds new light on the preservation of soft parts in fossils of backboned animals. Although most of the animal fossils in museum collections were formed from hard body parts such as bones, teeth and shells, the researchers say their work shows soft parts can become fossilized under certain circumstances and can provide valuable information.&nbsp;



“An important conclusion is that these kinds of soft parts can be preserved, and they may be preserved in fossils that we’ve had for a long time – this is a fossil that’s been known for over 100 years," said study senior author Matt Friedman.



The small skull is the only fossil of the extinct species ever to have been found. For this reason, the researchers had to use non-invasive methods to analyze it. They suggest that&nbsp;C. wildi was an early ray-finned fish, roughly the size of a bream (6–8 inches long), that swam in an estuary and probably preyed on small crustaceans, aquatic insects and cephalopods, a group that today includes squid, octopuses and cuttlefish. Ray-finned fishes have backbones and fins supported by bony rods called rays.&nbsp;



The exceptionally preserved brain had another surprise in store for the researchers. Ray-finned fish show an unusual feature in the early formation of their brains. The embryonic neural tube grows through eversion (folding inwards) of the dorsal walls of the forebrain. This results in a forebrain formed in two solid hemispheres that do not enclose a ventricle (cavity filled with cerebrospinal fluid).&nbsp;



This is different from early brain development in all other vertebrates, for example mammals, birds and reptiles. Their embryonic neural tubes grow by evagination (folding outwards) of the lateral walls of the forebrain, which forms two swellings that each enclose a large ventricle. Thus ray-finned fish show a unique pattern of early brain development. But this is not true for C. wildi.&nbsp;



C. wildi is the only example of a ray-finned fish that does not show the brain development typical of its group. Its brain develops in the same way as in other vertebrate groups, making it different from all living ray-finned fishes. The researchers say that C. wildi thus gives an indication of what the original path of brain development could have been, and that the principle neuroanatomical feature of all modern ray-finned fish (namely an everted forebrain) originated somewhere subsequently along the evolutionary pathway of the group.&nbsp;



“This unexpected find of a three-dimensionally preserved vertebrate brain gives us a startling insight into the neural anatomy of ray-finned fish. It tells us a more complicated pattern of brain evolution than suggested by living species alone, allowing us to better define how and when present day bony fishes evolved," explained study senior author Sam Giles.



“Comparisons to living fishes showed that the brain of Coccocephalus is most similar to the brains of sturgeons and paddlefish, which are often called ‘primitive’ fishes because they diverged from all other living ray-finned fishes more than 300 million years ago.”



Thus, the exceptional small fossil gives a window into brain development at a time before the signature feature of ray-finned fish brains evolved, providing an indication of what the primitive brain anatomy could have been in the very early ray-finned fish. Since an everted forebrain is absent in C. wildi, it indicates that this feature evolved during later evolution of the group.&nbsp;



“Not only does this superficially unimpressive and small fossil show us the oldest example of a fossilized vertebrate brain, but it also shows that much of what we thought about brain evolution from living species alone will need reworking," said study lead author Rodrigo Figueroa.



The authors also highlight the importance of searching for fossilized brains within the skulls of other preserved fish and vertebrates. They state that preservation of brain tissue is likely to be more common than previously thought, and that if researchers assume brains will not have fossilized, they run the risk of overlooking potentially valuable information.&nbsp;



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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



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319-million-year-old fish holds clues about brain evolution

The skull of a fish that lived around 319 million...

In a new study led by <a href="https://www.curtin.edu.au/">Curtin University</a>, experts report that <a href="https://www.earth.com/news/fireworks-release-toxic-metals-that-can-harm-human-cells/">fireworks</a> should be replaced with cleaner drone and laser light shows to prevent "highly damaging” impacts. Lead author Professor Bill Bateman noted that fireworks remain globally popular despite the overwhelming evidence that they negatively impact wildlife, domestic animals, and the environment.



“Fireworks create short-term noise and light disturbances that cause distress in domestic animals that may be managed before or after a firework event, but the impacts to wildlife can be on a much larger scale,” said Professor Bateman.



“The annual timing of some large-scale firework events coincides with the migratory or reproductive movements of wildlife, and may therefore have adverse long-term population effects on them. Fireworks also produce significant pulses of highly pollutant materials that also contribute significantly to the chemical pollution of soil, water, and air, which has implications for human as well as animal health.”



To investigate the potential harm caused by firework displays, the researchers reviewed the ecological effects of Diwali festivities in India, Fourth of July celebrations across the United States, and other events in New Zealand and Europe.&nbsp;



The review confirmed that fireworks affect wildlife in the long-term. For example, the experts found that sea lions along the coastline of Chile have changed their breeding season as a result of New Year’s fireworks. In California, July firework displays are associated with a decline of Brandt’s cormorant colonies. Furthermore, Spanish festivals have been linked to lower breeding success among house sparrows.



Professor Bateman said that firework bans at sensitive periods for wildlife migration or mating periods could limit these ecological impacts.



“Other than horses, for which there is some evidence that they can be gradually familiarized with flashes of light, there is very little that can be done to address the disturbing impact of noise from fireworks on animals and wildlife,” said Professor Bateman.



“The future of firework displays may be in the use of safer and greener alternatives such as drones, eco-friendly fireworks or visible-wavelength lasers for light shows."



“There is growing evidence that these community events can be managed in a sustainable way and it’s clear that out-dated firework displays need to be replaced by cleaner options that are not harmful to wildlife and the environment.”



The study authors noted that firework residues also contribute significantly to chemical pollution of soil, water, and air, which has implication for human as well as animal health.&nbsp;



"Modern technological alternatives to traditional fireworks - both ‘eco-friendly’ fireworks, and reusable drone and laser-based light shows - provide safer, ‘greener’ alternatives that also present a sustainable way forward for maintaining cultural traditions without perpetuating their adverse impacts," wrote the researchers.



The study is published in the journal <a href="http://dx.doi.org/10.1071/PC22040">Pacific Conservation Biology</a>.



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



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Fireworks have long lasting impacts on wildlife

In a new study led by Curtin University, experts report...

Honey bees are crucial <a href="https://www.earth.com/news/gardeners-can-make-small-changes-to-benefit-pollinators/">pollinators</a> of flowers, enabling the plants to form seeds and fruit, and reproduce successfully. In addition, around one-third of food eaten in by Americans comes from crop plants that are pollinated by honey bees. The collapse of bee colonies thus poses a threat to food security and is a phenomenon that concerns beekeepers across the U.S. and worldwide.



The sudden disappearance of all the worker bees from a colony, leaving a queen, a few nurse bees and the immature brood, is what characterizes colony collapse. The colony cannot survive without the worker bees, and so it will die off in time. There is currently no all-embracing explanation for why this occurs to certain bee hives and the research that has been conducted usually focuses on the effects of one stressor, such as parasites, or on a combination of stressors in one isolated region or geographical area.&nbsp;



A new study, published in the journal <a href="http://dx.doi.org/10.1038/s41598-023-28374-w">Scientific Reports</a>, has taken the analysis of variables, recognized as potential contributors to colony collapse, to a higher level. The researchers conducted a large-scale, multi-variable analysis using publicly accessible datasets from across the contiguous U.S. In particular, they used weather data for the years 2015–2021, and combined open data on honey bee colony status and stressors, weather data, and land use, in order to understand the relationships between the disappearance of bee colonies and the various stressors.



“Honey bees are vital pollinators for more than 100 species of crops in the United States, and the widespread loss of honey bee colonies is increasingly concerning,” said Luca Insolia, first author of the study, a visiting graduate student in the Department of Statistics at <a href="https://www.psu.edu/">Penn State</a> at the time of the research, and currently a postdoctoral researcher at the University of Geneva in Switzerland.&nbsp;



“Some previous studies have explored several potential stressors related to colony loss in a detailed way but are limited to narrow, regional areas. The one study that we know of at the national level in the United States explored only a single potential stressor. For this study, we integrated many large datasets at different spatial and temporal resolutions and used new, sophisticated statistical methods to assess several potential stressors associated with colony collapse across the U.S.”



One of the main reasons for the lack of previous analyses at the national level is the absence of same-source or same-resolution databases. For example, weather data may be available on a daily scale, but information on colony disappearances may only be collected by apiculture groups on a quarterly basis. Because these data differ in spatio-temporal resolution, the researchers used a method of data up-scaling, rather than averaging the information to the lowest resolution available, which would mean a loss of detail.



“In order to analyze the data all together, we had to come up with a technique to match the resolution of the various data sources,” said Martina Calovi, corresponding author of the study, a postdoctoral researcher in the Department of Ecosystem Science and Management at Penn State at the time of the research, and currently an associate professor of geography at the Norwegian University of Science and Technology.&nbsp;



“We could have just taken an average of all the weather measurements we had within a state, but that boils all the information we have into one number and loses a lot of information, especially about any extreme values. In addition to averaging weather data, we used an ‘upscaling’ technique to summarize the data in several different ways, which allowed us to retain more information, including about the frequency of extreme temperature and precipitation events.”



The researchers used the resulting integrated resolution-matched dataset – which they have made available for use by other researchers – alongside sophisticated statistical modeling techniques that they developed to assess the large number of potential stressors at the same time.



The research team found that several stressors impacted honey bee colony loss at the national level, including the use of pesticides nearby, frequent extreme weather events, and weather instability. Colony loss was also related to the presence of parasitic mites, Varroa destructor, which reproduce in honey bee colonies, weaken the bees, and potentially expose them to viruses. The researchers also found that losses typically occurred between January and March, probably reflecting the harsher conditions endured by bees while overwintering.&nbsp;



“Our results largely reinforce what regional studies have observed and confirm that regional patterns around these stressors are actually more widespread,” said Insolia, a beekeeper himself. “These results also inform actions that beekeepers could take to help circumvent these stressors and protect their colonies, including treatments for the Varroa mites‚ especially in areas of weather instability. Beekeepers could also consider strategies to move their colonies to areas with high food availability or away from nearby pesticides or to provide supplementary food during certain seasons or months with frequent extreme weather events.”



The researchers suggest that having data about beekeeping practices, such as treating colonies for Varroa mites and recording colony losses, at a finer resolution would allow validation of their results as well as a more detailed understanding of factors that act as stressors for honey bees.&nbsp;



“It would be incredibly beneficial to explore beekeeping practices at a finer scale than the state level,” said Calovi. “In many cases, beekeeping associations and other organizations collect this data, but it is not made available to researchers. We hope our study will help motivate more detailed data collection as well as efforts to share that data – including from smaller organizations such as regional beekeeper associations.”



The research team also found a strong relationship between colony loss and a broad category of beekeeping practices noted on a USDA survey as "other," which contained everything from hives being destroyed, to food scarcity for bees, to queen failure. They noted that collecting this data in more detail and breaking up this catch-all type variable into smaller categories would improve their ability to identify links between particular stressors and colony collapses.



“A changing climate and high-profile extreme weather events like Hurricane Ian – which threatened about 15 percent of the nation’s bees that were in its path as well as their food sources – are important reminders that we urgently need to better understand the stressors that are driving honey bee colony collapse and to develop strategies to mitigate them,” said Francesca Chiaromonte, professor of statistics and the holder of the Lloyd and Dorothy Foehr Huck Chair in Statistics for the Life Sciences at Penn State and a senior member of the research team.&nbsp;



“Our results highlight the role of parasitic mites, pesticide exposure, extreme weather events, and overwintering in bee colony collapse,” she concluded. “We hope that they will help inform improved beekeeping practices and direct future data collection efforts that allow us to understand the problem at finer and finer resolutions.”



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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



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What is causing honey bee colony collapse in the U.S.?

Honey bees are crucial pollinators of flowers, enabling the plants...

Rapid climate change is forcing many species to evolve and adapt quickly enough to avoid extinction, particularly those that do not tolerate a large degree of environmental variation, such as species from cooler high-elevation habitats, which often lack the genetic diversity that is crucial for adapting to global warming.



According to a new study led by <a href="https://www.flinders.edu.au/">Flinders University</a> in Australia, <a href="https://www.earth.com/news/hybridization-among-wild-baboons-comes-with-hidden-costs/">hybridization</a> – the process of mixing different species – could potentially help the most vulnerable ones adapt and rapidly exploit novel genetic diversity from species that are already adapted to warmer environments. This concept is similar to how the historic mixing between our ancestors and Neanderthals seems to have improved the fitness of some modern human populations.



To test this hypothesis, the scientists traveled to the Wet Tropics region of northeastern Australia to collect samples of five species of tropical rainbowfish along an elevation gradient. Genetic analysis of the samples revealed both pure and hybrid populations of rainbowfish, and helped the researchers identify genes that enable rainbowfish populations to adapt to climate variation.



More specifically, the populations of cool-adapted upland species that have hybridized with a warm-adapted lowland species showed reduced vulnerability to future warming scenarios. “These mixed populations contain more diversity at genes we think are important for climate adaptation, and are therefore more likely to persist in warmer environments,” explained study lead author Chris Brauer, a research fellow in Landscape Genomics at Flinders University.&nbsp;



These findings highlight the underappreciated conservation value of hybrid populations, suggesting that hybridization may facilitate rapid adaptation to climate change. “Our findings are good news for biodiversity. They indicate that genetic mixing is an important tool for conservation that can contribute to natural evolutionary rescue of species threatened by climate change,” concluded senior author Luciano Beheregaray, a professor of Biodiversity Genomics at Flinders.



The study published in the journal <a href="about:blank">Nature Climate Change</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



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Hybridization reduces vulnerability to climate change

Rapid climate change is forcing many species to evolve and...

There has been much research recently exploring the role of the gut microbiome in the health of humans and other <a href="https://www.earth.com/news/can-we-communicate-with-animals-using-artificial-intelligence/">animals</a>. Indeed, mammalian gut microbes have been shown to affect aspects of development, digestion, physiology, metabolism, immunity, mental health and behavior. In addition, individuals with autism or autistic-like behaviour are known to have altered gut microbe communities. Thus, the relationship between the microbiome and behavior is reciprocal, since social interactions can influence the gut microbiome, which in turn can affect social behavior.



With these connections in mind, researchers from the University of Oxford, U.K., and the University of Boulder, Colorado, set out to investigate the relationship between the gut microbiome and the social behavior of wild rhesus macaque monkeys (Macaca mulatta) on the island of Cayo Santiago, off Puerto Rico. In particular, they wondered whether monkeys with better social networks have healthier gut microbiomes compared to individuals that are less connected.&nbsp;



Macaques have an Asian origin and are found in many countries, including India, Thailand, China, Pakistan, Nepal, Bangladesh, and Vietnam. A group of 409 was introduced onto the 15.2 ha island of Cayo Santiago in 1938, and their behavior and social relationships have been studied there ever since. They live in social groups composed of a few adult males and many adult females and their offspring, and grooming is their primary means of making and maintaining relationships. Grooming interactions are thus a good indicator of social connectedness between individuals.



In this study, published in the journal <a href="http://dx.doi.org/10.3389/fmicb.2022.1032495">Frontiers in Microbiology</a>, 50 uncontaminated fecal samples were collected from a specific group of macaques between 2012 and 2013. The group consisted of 22 males and 16 females between the ages of six and 20 years. Social connectedness between group members was measured in terms of the time each monkey spent grooming or being groomed during this two-year period, as well as his or her number of grooming partners. In this way, the researchers could correlate social connectedness with the gut microbiome composition of the monkeys in the group.&nbsp;



“Macaques are highly social animals and grooming is their main way of making and maintaining relationships, so grooming provides a good indicator of social interactions," explained study co-author Dr. Karli Watson from the Institute of Cognitive Science at CU Boulder.



DNA analysis of gut microbes was conducted by the researchers to find out how microbiome diversity within and between macaques was related to grooming interactions, whilst controlling for the effects of rank, sex, age, season and sampling year. The results showed that gut microbiome composition differed considerably between individuals in the group, as did the extent of social interactions.&nbsp;



Specifically, the amount of grooming an individual received was a significant factor explaining differences in microbiome composition between macaques. Put simply, monkeys that had more friends who groomed them also had more gut microbes associated with healthy functions, and fewer microbes associated with disease.&nbsp;



“Engagement in social interactions was positively related to the abundance of certain gut microbes with beneficial immunological functions, and negatively related to the abundance of potentially pathogenic members of the microbiota,” said co-author Dr. Philip Burnet, a professor in the Department of Psychiatry at the University of Oxford.



For example, genera more abundant in the most sociable monkeys included Faecalibacterium&nbsp;and&nbsp;Prevotella. Conversely, the genus&nbsp;Streptococcus, which in humans can cause diseases such as strep throat and,&nbsp;pneumonia, was most abundant in less sociable monkeys.



Lead author Dr. Katerina Johnson, a research associate at the Department of Experimental Psychology and the Department of Psychiatry of the University of Oxford, said: “Here we show that more sociable monkeys have a higher abundance of beneficial gut bacteria, and a lower abundance of potentially disease-causing bacteria. It is particularly striking that we find a strong positive relationship between the abundance of the gut microbe&nbsp;Faecalibacterium&nbsp;and how sociable the animals are.&nbsp;Faecalibacterium&nbsp;is well known for its potent anti-inflammatory properties and is associated with good health.”



These findings are also consistent with findings in human populations where autism is associated with an altered gut microbial community. Autistic individuals engage in less social contact and it is possible that limited social interactions influence the gut microbiome negatively. However, the converse may also be true, namely that a distinctly altered gut microbiome may affect behavioral traits and, therefore, sociability. In this way, it is possible that the relationship between these two variables is indeed reciprocal.&nbsp;



Although none of the monkeys in the test group was classified as autistic, some were more sociable than others, and took part in more grooming activities. Just as in human society, some individuals show more social behavior while others are more isolated. Grooming in macaques involves hand-to-mouth actions and this undoubtedly affects the microbial community in the gut. Previous research has shown that grooming leads to increased similarity in the gut microbiomes of individual monkeys in social groups.&nbsp;



“The relationship between social behavior and microbial abundances may be the direct result of social transmission of microbes, for example through grooming. It could also be an indirect effect, as monkeys with fewer friends may be more stressed, which then affects the abundance of these microbes. As well as behavior influencing the microbiome, we also know it is a reciprocal relationship, whereby the microbiome can in turn affect the brain and behavior,” said Johnson.



"As our society is increasingly substituting online interactions for real-life ones, these important research findings underline the fact that as primates, we evolved not only in a social world but a microbial one as well," said study co-author Dr. Robin Dunbar, a professor from the Department of Experimental Psychology at the University of Oxford.



The authors conclude: “Our findings advance our understanding of how gut microbial communities may be associated with host behavior and reveal that social relationships may be intertwined with health and immune status&nbsp;via&nbsp;the microbiota.”



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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



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