Genomes of the earliest Europeans

Ancient genomes shed new light on the earliest Europeans and their relationships with Neandertals

MAX-PLANCK-GESELLSCHAFT

Research News

 

IMAGE: THE NICHE 1 SECTOR (LEFT) AND THE MAIN SECTOR (RIGHT) DURING THE EXCAVATIONS OF BACHO KIRO CAVE, BULGARIA, IN 2016. THE CEMENT AREA IN THE FOREGROUND WAS PREVIOUSLY EXCAVATED IN... view more 

CREDIT: MPI-EVA/ NIKOLAY ZAHERIEV

An international research team has sequenced the genomes of the oldest securely dated modern humans in Europe who lived around 45,000 years ago in Bacho Kiro Cave, Bulgaria. By comparing their genomes to the genomes of people who lived later in Europe and in Asia the researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, show that this early human group in Europe contributed genes to later people, particularly present-day East Asians. The researchers also identified large stretches of Neandertal DNA in the genomes of the Bacho Kiro Cave people, showing that they had Neandertal ancestors about five to seven generations back in their family histories. This suggests that mixture with Neandertals was the rule rather than the exception when the first modern humans arrived in Europe.

Last year, a research team led by researchers from the National Institute of Archaeology with Museum at the Bulgarian Academy of Sciences and the Max Planck Institute for Evolutionary Anthropology, Germany, reported the discovery of modern human remains found in direct association with the Initial Upper Palaeolithic stone tools at the site of Bacho Kiro Cave in Bulgaria. The oldest individuals found in the cave were directly radiocarbon dated to between 43,000 and 46,000 years ago. They are thus the earliest known dispersal of modern humans across the mid-latitudes of Eurasia.

Mateja Hajdinjak and colleagues have now sequenced the genomes of five individuals found at the Bacho Kiro Cave. Four individuals are between 43,000 to 46,000-years-old and were found together with stone tools belonging to the Initial Upper Palaeolithic, the earliest culture associated with modern humans in Eurasia. An additional individual found in the cave is around 35,000-years-old and found with stone tools of a later type. It was previously thought that bearers of the Initial Upper Palaeolithic died out without contributing genetically to modern humans arriving later. However, the researchers now show that the oldest Bacho Kiro Cave individuals, or groups closely related to them, contributed genes to present-day people. Surprisingly, this contribution is found particularly in East Asia and the Americas rather than in Europe where the Bacho Kiro Cave people lived. These genetic links to Asia mirror the links seen between the Initial Upper Palaeolithic stone tools and personal ornaments found in Bacho Kiro Cave and tools and ancient jewelry found across Eurasia to Mongolia.

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Second lower molar of a modern human found in Bacho Kiro Cave in the Main sector associated with the Initial Upper Palaeolithic stone tools. Genome-wide data from this individual indicates that he had a Neandertal ancestor less than six generations before he lived. Another human fragment from the same individual was found in the Layer I in the Niche 1 area of the cave.

CREDIT

MPI-EVA/ Rosen Spasov

Genetic differences between individuals

Importantly, the later 35,000-year-old individual found in Bacho Kiro Cave belonged to a group that was genetically distinct from the earlier inhabitants of the cave. This shows that the earliest history of modern humans in Europe may have been tumultuous and involved population replacements.

The earliest people at Bacho Kiro Cave lived at a time when Neandertals were still around. The researchers therefore scanned their genomes for fragments of Neandertal DNA. "We found that the Bacho Kiro Cave individuals had higher levels of Neandertal ancestry than nearly all other early humans, with the exception of a 40,000-year-old individual from Romania. Crucially, most of this Neandertal DNA comes in extremely long stretches. This shows that these individuals had Neandertal ancestors some five to seven generations back in their family trees" says Mateja Hajdinjak.

Although only a handful of genomes from modern humans who lived at the same time in Eurasia as some of the last Neandertals have been recovered, nearly all of them have recent Neandertal ancestors. "The results suggest that the first modern humans that arrived in Eurasia mixed frequently with Neandertals. They may even have become absorbed into resident Neandertal populations. Only later on did larger modern human groups arrive and replace the Neandertals" says Svante Pääbo, who coordinated the genetic research.

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Red deer have personality and it is related to their dominance behavior

UNIVERSITY OF TURKU

Research News

 

IMAGE: TWO MALE RED DEERS FIGHTING view more 

CREDIT: UNIVERSITY OF TURKU

An international team of researchers has studied individual differences in the behaviour of red deer. They found that several observed behaviours form a personality component, which they labelled "Confidence/Aggressiveness".

As is commonly known, individual people behave consistently different from each other and these kinds of consistent differences in behaviour are called personality. Studies on species other than humans, from insects to elephants, have found that personalities are widespread in nature.

The team consists of researchers from the Czech University of Life Sciences Prague, the University of South Bohemia, Czech Republic, the University of Vienna, Austria, and the University of Turku, Finland and is led by Bruno Esattore from the Department of Ethology at the Institute of Animal Science in Prague. The team of researchers studied personality of red deer with a newly developed questionnaire, as well as observed their behaviours.

The researchers identified a single personality component related to Confidence/Aggressiveness. Interestingly, some of the behaviours making up this component were linked with dominance behaviour in red deer. The study has just been published in Behavioural Processes.

- Many personality studies have focused on primates, rodents, birds, field crickets or fish. Despite of their well-studied biology and increasing popularity in the farming sector, the personality structure of one of Europe's most iconic mammals, the red deer, has until now been unknown, says the lead author of the study Bruno Esattore.

The personality data were collected by using a novel questionnaire for which experienced observers rated 15 behaviours on a scale from 1 to 5, with 1 meaning the deer shows this behaviour "Almost never" and 5 meaning "Most of the time".

- We think it is extremely interesting that inter-individual differences which have been so far overlooked or even regarded as distracting are those that eventually make the difference when trying to identify the personality of these animals, states Doctoral Candidate Laura Saggiomo from the Faculty of Forestry and Wood Sciences of the Czech University of Life Sciences Prague.

- These findings are exciting, but of course, they are not the final picture of how personality manifests in red deer, says Postdoctoral Researcher Vedrana Šlipogor from the Department of Zoology of the University of South Bohemia in Budweiss, Czech Republic.

The team put lots of care into the making of the questionnaire, however, for a majority of the 15 behaviours the observers did not agree very well on their ratings of the deer.

- This was an unexpected result and shows that we have to be careful with our behavioural descriptions and to consider observer perceptions when using questionnaire ratings of animal behaviour for scientific studies, Šlipogor further states.

The team then linked these findings with observations of the dominance interactions of the male deer in their bachelor groups.

- We found no relationship between deer's dominance and personality, but dominance was related to some of the rated behaviours, showing our personality questionnaire captured some biologically meaningful variation, says Bruno Esattore.

Studies on animals kept in zoos or different facilities or farms have shown that knowing the individual characteristics or personalities of animals can help to implement the best strategy in guaranteeing their welfare.

- Personality has not been largely considered in welfare management decisions, but lately it is receiving more and more attention. We believe that studies like ours can help to add to the improvement of animal management and welfare, concludes Martin Seltmann from the Department of Biology at the University of Turku.

Genome sequencing reveals a new species of bumblebee

UPPSALA UNIVERSITY

Research News

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IMAGE: THE NEWLY DISCOVERED BOMBUS INCOGNITUS LOOKS IDENTICAL TO ANOTHER SPECIES, BOMBUS SYLVICOLA. IT IS IMPOSSIBLE TO SAY WHICH ONE OF THE TWO IS SEEN IN THIS PHOTO. view more 

CREDIT: JENNIFER GEIB

While studying genetic diversity in bumblebees in the Rocky Mountains, USA, researchers from Uppsala University discovered a new species. They named it Bombus incognitus and present their findings in the journal Molecular Biology and Evolution.

Bumblebees are vital for agriculture and the natural world due to their role in plant pollination. There are more than 250 species of bumblebee, and they are found mainly in northern temperate regions of the planet. Alarmingly, many species are declining due to the effects of climate change, and those with alpine and arctic habitats are particularly threatened. However, the full diversity of bumblebee species in these environments is still unknown.

Matthew Webster's research group at Uppsala University, together with colleagues in the USA, studied genetic diversity in bumblebees in the Rocky Mountains, Colorado by collecting hundreds of samples and sequencing their genomes. Surprisingly, the data revealed the presence of a new species, which was indistinguishable in appearance to the species Bombus sylvicola, but clearly distinct at the genetic level. The authors named this species Bombus incognitus.

By comparing the genomes of Bombus sylvicola and Bombus incognitus, the team were able to learn about how this new species formed. They found signals consistent with gene flow between the species during their evolution. They also identified parts of chromosomes that are incompatible between species, which act as genetic barriers to gene flow and were likely important in causing the species to separate.

These results indicate that the number of bumblebee species in arctic and alpine environments may be larger than previously thought. It is possible that mountainous terrain is conducive to speciation. Cold-adapted populations could become isolated at high altitudes during periods of warming in their evolutionary history, leading to the formation of new species. It is also possible that additional genome sequencing of bumblebees will reveal even more cryptic species that have so far gone undetected.

CAPTION

The newly discovered Bombus incognitus looks identical to another species, Bombus sylvicola. It is impossible to say which one of the two is seen in this photo.

CREDIT

Jennifer Geib

CAPTION

The newly discovered Bombus incognitus looks identical to another species, Bombus sylvicola. It is impossible to say which one of the two is seen in this photo.

CREDIT

Jennifer Geib

 

Scientists discover two new species of ancient, burrowing mammal ancestors

120-million-year-old animals evolved "scratch-digging" traits independently

AMERICAN MUSEUM OF NATURAL HISTORY

Research News

 

IMAGE: THIS PORTRAIT SHOWS THE TRITYLODONTID FOSSIOMANUS SINENSIS (UPPER RIGHT) AND THE EUTRICONODONTAN JUECONODON CHENI IN BURROWS; BOTH LIVED THE EARLY CRETACEOUS JEHOL BIOTA (ABOUT 120 MILLION YEARS AGO), NORTHEASTERN CHINA,... view more 

CREDIT: © CHUANG ZHAO

Paleontologists have discovered two new species of mammal-like, burrowing animals that lived about 120 million years ago in what is now northeastern China. The new species, described today in the journal Nature, are distantly related but independently evolved traits to support their digging lifestyle. They represent the first "scratch-diggers" discovered in this ecosystem.

"There are many hypotheses about why animals dig into the soil and live underground," said lead author Jin Meng, a curator in the American Museum of Natural History's Division of Paleontology. "For protection against predators, to maintain a temperature that's relatively constant--not too hot in the summer and not too cold in the winter--or to find food sources like insects and plant roots. These two fossils are a very unusual, deep-time example of animals that are not closely related and yet both evolved the highly specialized characteristics of a digger."

The fossil mammaliamorph species--predecessors to mammals--were discovered in the Jehol Biota, which represents the Early Cretaceous epoch, about 145 to 100 million years ago. One is a mammal-like reptile called a tritylodontid and is the first of its kind to be identified in this biota. About a foot in length, it was given the name Fossiomanus sinensis (Fossio, "digging" and manus "hand;" sinensis, "from China"). The other is named Jueconodon cheni (Jue, "digging"--Chinese pinyin--and conodon "cuspate tooth"; cheni for Y. Chen, who collected the fossil). It is a eutriconodontan, a distant cousin of modern placental mammals and marsupials, which were common in the habitat. It is about 7 inches long.

Mammals that are adapted to burrowing have specialized traits for digging. The researchers found some of these hallmark features--including shorter limbs, strong forelimbs with robust hands, and a short tail--in both Fossiomanus and Jueconodon. In particular, these characteristics point to a type of digging behavior known as "scratch digging," accomplished mainly by the claws of the forelimbs.

"This is the first convincing evidence for fossorial life in those two groups," Meng said. "It also is the first case of scratch diggers we know about in the Jehol Biota, which was home to a great diversity of life, from dinosaurs to insects to plants."

The animals also share another unusual feature: an elongated vertebral column. Typically, mammals have 26 vertebrae from the neck to the hip. However, Fossiomanus had 38 vertebrae--a staggering 12 more than the common state--while Jueconodon had 28. To try to determine how these animals got their elongated trunks, the paleontologists turned to recent studies in developmental biology, finding that the variation could be attributed to gene mutations that determine the number and shape of the vertebrae in the beginning of the animals' embryotic development. Variation in vertebrae number can be found in modern mammals as well, including in elephants, manatees, and hyraxes.

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Reconstruction of Fossiomanus senensis and Jueconodon cheni

CREDIT

ZHAO Chuang

Other authors on the study include Fangyuan Mao from the Chinese Academy of Sciences and the American Museum of Natural History, Chi Zhang from the Chinese Academy of Sceinces, and Cunyu Liu from the Beipiao Pterosaur Museum of China.

This study was supported in part by the National Natural Science Foundation of China, grant no.s 41688103 and 42072002; the Chinese Academy of Sciences Strategic Priority Research Program, Youth Innovation Promotion Association, and 100 Young Talents Program; and the Kalbfleisch Fellowship of the American Museum of Natural History's Richard Gilder Graduate School.

Study DOI: 10.1038/s41586-021-03433-2

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Holotype specimens of Fossiomanus senensis and Jueconodon cheni

CREDIT

MAO Fangyuan

ABOUT THE AMERICAN MUSEUM OF NATURAL HISTORY (AMNH)

The American Museum of Natural History, founded in 1869 and currently celebrating its 150th anniversary, is one of the world's preeminent scientific, educational, and cultural institutions. The Museum encompasses more than 40 permanent exhibition halls, including those in the Rose Center for Earth and Space, as well as galleries for temporary exhibitions. The Museum's approximately 200 scientists draw on a world-class research collection of more than 34 million artifacts and specimens, some of which are billions of years old, and on one of the largest natural history libraries in the world. Through its Richard Gilder Graduate School, the Museum grants the Ph.D. degree in Comparative Biology and the Master of Arts in Teaching (MAT) degree, the only such free-standing, degree-granting programs at any museum in the United States. The Museum's website, digital videos, and apps for mobile devices bring its collections, exhibitions, and educational programs to millions around the world. Visit amnh.org for more information.

 

Why lists of worldwide bird species disagree

Data gaps and species similarities may lead to undercounting biodiversity

UNIVERSITY OF UTAH

Research News

 

IMAGE: A CHAMÍ ANTPITTA, WHICH WAS RECENTLY SPLIT AS A DISTINCT SPECIES FROM THE RUFOUS ANTPITTA. view more 

CREDIT: ÇA?AN ?EKERCIO?LU

How many species of birds are there in the world? It depends on whose count you go by. The number could be as low as 10,000 or as high as 18,000. It's tough to standardize lists of species because the concept of a "species" itself is a little bit fuzzy.

That matters because conserving biodiversity requires knowing what diversity exists in the first place. So biologists, led by University of Utah doctoral candidate Monte Neate-Clegg of the School of Biological Sciences, set out to compare four main lists of bird species worldwide to find out how the lists differ--and why. They found that although the lists agree on most birds, disagreements in some regions of the world could mean that some species are missed by conservation ecologists.

"Species are more than just a name," Neate-Clegg says. "They are functional units in complex ecosystems that need to be preserved. We need to recognize true diversity in order to conserve it."

The results are published in Global Ecology and Biogeography.

On the origin of species

The definition of a species isn't clear-cut. Some scientists define populations as different species if they're reproductively isolated from each other and unable to interbreed. Others use physical features to delineate species, while yet others use genetics. Using the genetic definition produces many more species, but regardless of the method, gray areas persist.

"Species are fuzzy because speciation as a process is fuzzy," Neate-Clegg says. "It's a gradual process so it's very difficult to draw a line and say 'this is two species' vs. 'this is one species.'"

Also, he says, physical features and genetic signatures don't always diverge on the same timescale. "For example," he says, "two bird populations may diverge in song and appearance before genetic divergence; conversely, identical populations on different islands may be separated genetically by millions of years."

Comparing the lists

At this point in the story, it's time to introduce four lists, each of which purports to include all the bird species in the world. They are:

• The Howard and Moore Checklist of the Birds of the World
• The eBird/Clements Checklist of Birds of the World
• The BirdLife International Checklist of the Birds of the World
• The International Ornithological Community (IOC) World Bird List

"Being active field ornithologists who are always trying to ID bird species means that one is always faced with the issue of some species being on one list but not the other," says Çağan Şekercioğlu, associate professor in the School of Biological Sciences. "So our field experience very much primed us to think about this question and inspired us to write this paper."

The lists have different strengths depending on their application. The BirdLife International list, for example, integrates with the IUCN Red List, which reports on species' conservation status. The IOC list is updated by experts twice a year, Şekercioğlu says. The list is open access with comparisons to other major lists, and changes are documented transparently.

"But as a birdwatcher, I use eBird all the time, which uses the Clements checklist, and that dataset is very powerful in its own right," Neate-Clegg says. "So there is no single best option."

One example of the disagreement between lists might be the common bird Colaptes auratus. The eBird list calls it the northern flicker, a woodpecker. But the BirdLife International list delineates the eastern population as the yellow-shafted flicker and the western population as the red-shafted flicker.

In 2020, Neate-Clegg and his colleagues read a study that compared the raptor species on each list, finding that only 68% of species were consistent among all four lists.

"We thought it would be interesting to investigate taxonomic agreement for all 11,000 bird species," Neate-Clegg says. "More importantly, we wanted to try and work out what species characteristics led to more or less taxonomic confusion."

They began by collecting the most recent version of each list (the IOC checklist is updated biannually, the researchers write, and the Clements and BirdLife lists annually, while Howard and Moore has not been updated since 2014) and trimming them down to exclude subspecies and any extinct species. Using a few other data processing rules, they assigned a single name to every possible species across all four lists. Then the comparisons began.

Where the lists agree and disagree

The researchers found that the four lists agreed on the vast majority of bird species--89.5%. For the remaining 10.5%, then, they started to look for patterns that might explain the disagreement. Some of it was likely geographical. Birds from the well-studied Northern Hemisphere were more likely to find agreement than birds from the relatively understudied Southeast Asia and the Southern Ocean.

Some of it was habitat-based. Agreement was higher for large, migratory species in relatively open habitats.

"I think the most surprising result was that agreement was not lower for highly forest-dependent species," Neate-Clegg says. "We expected these denizens of the rainforest floor to be the most cryptic and hard to study, with more uncertainty on their taxonomic relationships. Yet we found it was actually species of intermediate forest dependency that had lower taxonomic agreement. We believe that these species move about just enough to diverge, but not so much that their gene pools are constantly mixing."

And part of the issue with species classification on isolated islands, such as those in Southeast Asia and the Southern Ocean, was a phenomenon called "cryptic diversification." Although islands can foster species diversification because of their isolation, sometimes two populations on different islands can appear very similar, even though their genes suggest that they've been isolated from each other for millions of years. So, depending on the definition, two populations could count as two species or as only one.

"In addition," Neate-Clegg says, "it's very hard to test the traditional biological species concept on island fauna because we cannot know whether two populations can interbreed to produce fertile young if they are geographically isolated."

Why it matters

So what if some people disagree on species designations? Conservation actions are usually on the species level, Neate-Clegg says.

"If a population on one island goes extinct, people may care less if it's 'just a subspecies,'" he says. "And yet that island is potentially losing a functionally unique population. If it was recognized as a full species it might not have been lost."

Neate-Clegg hopes the study points ornithologists towards the groups of species that merit additional attention.

"We also want conservation biologists to recognize that cryptic diversity may be overlooked," he adds, "and that we should consider units of conservation above and below the species level."

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Find the full study here.

Ant responses to social isolation resemble those of humans

Social isolation results in changes of behavior and activity of immune and stress genes

JOHANNES GUTENBERG UNIVERSITAET MAINZ

Research News

 

IMAGE: AN ANT OF THE SPECIES TEMNOTHORAX NYLANDERI view more 

CREDIT: PHOTO/©: SUSANNE FOITZIK, JGU

Ants react to social isolation in a similar way as do humans and other social mammals. A study by an Israeli-German research team has revealed alterations to the social and hygienic behavior of ants that had been isolated from their group. The research team was particularly surprised by the fact that immune and stress genes were downregulated in the brains of the isolated ants. "This makes the immune system less efficient, a phenomenon that is also apparent in socially isolating humans - notably at present during the COVID-19 crisis," said Professor Susanne Foitzik, who headed up the study at Johannes Gutenberg University Mainz (JGU). The study on a species of ant native to Germany has recently been published in Molecular Ecology.

Effects of isolation in social insects little studied so far

Humans and other social mammals experience isolation from their group as stressful, having a negative impact on their general well-being and physical health. "Isolated people become lonely, depressed, and anxious, develop addictions more easily, and suffer from a weakened immune system and impaired overall health," added Professor Inon Scharf, lead author of the article and cooperation partner of the Mainz research group at Tel Aviv University in Israel. While the effects of isolation have been extensively studied in social mammals such as humans and mice, less is known about how social insects respond in comparable situations - even though they live in highly evolved social systems. Ants, for instance, live their entire lives as members of the same colony and are dependent on their colony mates. The worker ants relinquish their own reproductive potential and devote themselves to feeding the larvae, cleaning and defending the nest, and searching for food, while the queen does little more than just lay eggs.

The research team looked at the consequences of social isolation in the case of ants of the species Temnothorax nylanderi. These ants inhabit cavities in acorns and sticks on the ground in European forests, forming colonies of a few dozen workers. Young workers engaged in brood care were taken singly from 14 colonies and kept in isolation for varying lengths of time, from one hour to a maximum of 28 days. The study was conducted between January and March 2019 and highlighted three particular aspects in which changes were observed. After the end of their isolation, the workers were less interested in their adult colony mates, but the length of time they spent in brood contact increased; they also spent less time grooming themselves. "This reduction in hygienic behavior may make the ants more susceptible to parasites, but it is also a feature typical of social deprivation in other social organisms," explained Professor Susanne Foitzik.

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Drawing of a Temnothorax nylanderi worker ant

CREDIT

ill./©: Inon Scharf, Tel Aviv University

Stress due to isolation adversely affects the immune system

While the study revealed significant changes in the behaviors of the isolated insects, its findings with regard to gene activity were even more striking: Many genes related to immune system function and stress response were downregulated. In other words, these genes were less active. "This finding is consistent with studies on other social animals that demonstrated a weakening of the immune system after isolation," said Professor Inon Scharf.

The discovery by the team of biologists led by Professor Susanne Foitzik is the first of its kind, combining behavioral and genetic analyses on the effects of isolation in social insects. "Our study shows that ants are as affected by isolation as social mammals are and suggests a general link between social well-being, stress tolerance, and immunocompetence in social animals," concluded Foitzik, summarizing the results of the Israeli-German study. Foitzik is also collaborating with her Israeli partner Professor Inon Scharf and with co-author and group leader Dr. Romain Libbrecht of JGU on a new joint project on the fitness benefits and the molecular basis of spatial learning in ants, funded by the German Research Foundation (DFG).

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Related links:

https://www.blogs.uni-mainz.de/fb10-evolutionary-biology/research-groups/group-foitzik/ - Evolution and Behavioral Ecology of Ants group at the JGU Institute of Organismic and Molecular Evolution

Read more:

https://www.uni-mainz.de/presse/aktuell/10918_ENG_HTML.php - press release "Communication and waterproofing: Melting properties determine the biological functions of the cuticular hydrocarbon layer of ants" (26 Feb. 2020) ;

https://www.uni-mainz.de/presse/aktuell/7703_ENG_HTML.php - press release "Arms race between ant societies: Gene activity in defenders depends on invading slavemaking ants" (28 Feb. 2019) ;

https://www.uni-mainz.de/presse/aktuell/5983_ENG_HTML.php - press release "A study of ants provides information on the evolution of social insects" (10 Sept. 2018) ;

https://www.uni-mainz.de/presse/aktuell/5412_ENG_HTML.php - press release "Brood care gene steers the division of labor among ants" (19 June 2018) ;

https://www.uni-mainz.de/presse/aktuell/2007_ENG_HTML.php - press release "Chemical profile of ants adapts rapidly" (14 Aug. 2017)

One of Africa's rarest primates protected by... speedbumps

WILDLIFE CONSERVATION SOCIETY

Research News

ZANZIBAR CITY (April 7, 2021) - A new study revealed that a drastic reduction of deaths of one of Africa's rarest primates, the Zanzibar red colobus (Piliocolobus kirkeii), followed the installation of four speedbumps along a stretch of road where the species frequently crossed.

Zanzibar red colobus are found only in the Zanzibar archipelago and classified as Endangered by the IUCN Red List. Reliant on Unguja Island's forests for their survival, around half of the species population is found in Jozani-Chwaka Bay National Park.

In the study, published in Oryx - The International Journal of Conservation, primatologists from Bangor University, in collaboration with national park managers from Zanzibar and the Wildlife Conservation Society (WCS), assessed mortality from vehicle collisions - a growing threat faced by primates living in increasingly fragmented habitats crisscrossed by roads.

They found that historic data from the road traversing the national park showed that one colobus was killed on average every 2-3 weeks by traffic. After speedbumps were installed, this was reduced to one every six weeks.

While great progress, this mortality rate is still a significant threat to the species - especially given that natural predation tends to target weaker individuals, yet roadkill is indiscriminate, killing reproductively active adults as well as the very young and old.

Bangor primatologist and Director of the Zanzibar Red Colobus Project, Dr. Alexander Georgiev, and senior author of this study, said: "Cars are not selective in the animals they kill. This means that while natural predators may target the very young and old more often, cars are equally likely to kill reproductively active young adults, who would contribute the most to population growth. And this may be a problem."

Harry Olgun, now a PhD student at the University's School of Natural Sciences, led this study as part of his Masters research on the road ecology of the Zanzibar red colobus. Olgun said: "After the road at Jozani was surfaced but before the speedbumps were installed, a colobus was reported to have been killed every two to three weeks, resulting in perhaps about 12-17 percent annual mortality, according to one estimate. The recent data show that speedbumps have made a huge difference for the safety of the colobus. Adding more speedbumps would help reduce the risk further."

Dr. Tim Davenport, Director of Species Conservation & Science in Africa at WCS, who led the first countrywide census of the Zanzibar red colobus a few years ago and is a coauthor of the study, said: "As tourism grows in Zanzibar and habitat continues to shrink, using science to quantify and solve conservation problems has never been so important. Understanding the impact of vehicles on wildlife within a park, and implementing practical solutions is exactly what we as conservationists should be doing."

WCS (Wildlife Conservation Society)

MISSION: WCS saves wildlife and wild places worldwide through science, conservation action, education, and inspiring people to value nature. To achieve our mission, WCS, based at the Bronx Zoo, harnesses the power of its Global Conservation Program in nearly 60 nations and in all the world's oceans and its five wildlife parks in New York City, visited by 4 million people annually. WCS combines its expertise in the field, zoos, and aquarium to achieve its conservation mission. Visit: newsroom.wcs.org Follow: @WCSNewsroom. For more information: 347-840-1242.