Wednesday, October 15, 2025

The largest primate in the Americas could lose up to 61% of its climatically suitable habitat by 2090

Study predicts that the two species of muriquis will be restricted mainly to coastal regions of the Atlantic Forest, leaving populations in the interior seriously at risk.

Fundação de Amparo à Pesquisa do Estado de São Paulo

The northern muriqui (Brachyteles hypoxanthus) and the southern muriqui (B. arachnoides) are the two species of the largest genus of primates in the Americas. A study published in the Journal for Nature Conservation with support from FAPESP estimates that their habitat will be reduced by 44% and 61%, respectively, by 2090. In São Paulo, Brazil, the northern muriqui is expected to lose its entire climatically suitable area by the end of the century.

These figures only account for the effect of climate change on the species by the end of the century. They do not consider other factors that threaten primates and their habitats, such as deforestation, forest fragmentation, and hunting. Both muriquis are endemic to the Atlantic Forest and are classified as “critically endangered” by the International Union for Conservation of Nature (IUCN) (read more at agencia.fapesp.br/53161).

“Climate change alone won’t lead to the extinction of muriquis, according to our projections. But about half of the current climatically favorable area for them could disappear, which is quite worrying considering that there are other factors putting pressure on these species,” says Tiago Vasconcelos, the author of the study and a researcher in the Graduate Program in Biosciences at the Bauru campus of São Paulo State University (UNESP).

The work is part of a project supported by FAPESP under the Research Program on Global Climate Change (RPGCC).

The projections are made using specialized software based on data such as the current distribution of muriquis and climate information that is important for their physiological requirements. Current climate data are thus used to characterize the species’ preferences, which are then projected into different future climate change scenarios for the coming decades, such as changes in rainfall, warmer months, and drier days.

Challenge in the interior

Previous studies by other researchers had already indicated that climatically suitable areas for the two species of muriqui would be lost by the end of the century. However, Vasconcelos points to the extent of the damage in the short and medium term, specifically by the years 2030, 2050, 2070, and 2090.

“Other authors had already suggested a reduction in areas suitable for both species by 2050 and 2090, but we were able to point out the gradual loss that will occur throughout the century,” explains the researcher, who is currently a substitute professor in the Department of Biology and Zootechnics at the Faculty of Engineering (FEIS) at the Ilha Solteira campus of UNESP.

For example, in 2023, an article pointed out that areas expected to be lost by the southern muriqui would be in semi-deciduous forests (which lose part of their leaves during the dry season) in the interior of the states of Paraná and São Paulo. Vasconcelos reached similar conclusions in his current study, but adds that these areas will shrink even further, continuously, over the coming decades until the end of the century. There will also be a shift in the species’ range towards the northeast.

“This shift won’t occur with an increase in suitable areas, as is predicted to happen with some animal groups. On the contrary. With the significant loss of areas in the west of their current range, the remaining populations are likely to be restricted to the eastern part,” he explains.

Vasconcelos’s work indicates that the northern muriqui has experienced similar patterns of loss of climatically suitable areas over the decades, with an accelerated reduction expected between 2070 and 2090. Most of this species’ losses are expected to occur inland in the eastern and southern parts of Minas Gerais state, as well as central and western portions of Rio de Janeiro state. By 2090, São Paulo is expected to lose all climatically suitable areas for the species. By that year, only two large climatically suitable areas will remain for the northern muriqui. One will cover the northern population in the state of Bahia and northeastern Minas Gerais. The other will be in the state of Espírito Santo, with a smaller area in northern Rio de Janeiro.

The large climatically suitable areas that will concentrate most of the population by the end of the century are along the coast and associated with ombrophilous forests, a type of coastal or riparian vegetation that occurs in areas with high rainfall.

“Climate change is likely to pose particularly difficult challenges for populations of both species in inland areas associated with semi-deciduous forests.”

Solutions

The researcher emphasizes that the predictions only consider climate change, which could mask an even greater risk when considering synergistic threats, such as continuous habitat loss and forest fragmentation. Combined with the reduction of climatically suitable areas, this trend could lead to the isolation of muriqui populations and disrupt gene flow, which could affect the maintenance of viable populations. This could further reduce the species’ range. Local extinctions have already been documented in degraded areas of semi-deciduous forests.

Therefore, the author concludes the study by recommending a focus on conservation efforts for these populations and warning of the need for a better understanding of how they will respond to climate change in the coming decades.

In the medium and long term, the study emphasizes the importance of focusing efforts on protecting the two species of muriqui in coastal rainforests and identifying the best locations for ecological corridors to connect currently isolated populations.

“This would give the species the opportunity to maintain gene flow and persist as healthy populations in this century,” he concludes.

About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

Journal

Journal for Nature Conservation

DOI

10.1016/j.jnc.2025.127019

Article Title

Predicted losses over the 21st century in climatically suitable areas of threatened Muriquis (Primates, Brachyteles) in the Brazilian Atlantic Forest hotspot

African wildlife poop sheds light on what shapes the gut ecosystem

North Carolina State University

Nature calls for this gembok — image:
A study of elephants, giraffes and other wildlife in Namibia’s Etosha National Park underscores the ways in which the environment, biological sex, and anatomical distinctions can drive variation in the gut microbiomes across plant-eating species. Because the gut microbiome plays a critical role in animal health, the work can be used to inform conservation efforts. This photo shows a gembok in Etosha.
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Credit: James C. Beasley

A study of elephants, giraffes and other wildlife in Namibia’s Etosha National Park underscores the ways in which the environment, biological sex, and anatomical distinctions can drive variation in the gut microbiomes across plant-eating species. Because the gut microbiome plays a critical role in animal health, the work can be used to inform conservation efforts.

“This study is valuable because Etosha gave us the opportunity to sample such a large number of species under different environmental conditions,” says Erin McKenney, co-author of a paper on the work and an assistant professor of applied ecology at North Carolina State University. “That gives us meaningful insight into the role the environment plays in shaping the gut microbiome of herbivores.

“Unfortunately, this study may also be important for a second reason,” McKenney says. “Etosha is experiencing devastating wildfires affecting a huge section of the park. Because our samples were taken before the wildfires, these findings could inform recovery efforts by helping us understand how species’ microbiomes are adjusting to changes in diet that stem from the fire’s impact on the landscape.”

For this study, the researchers divided Etosha into three zones, depending on the amount of rainfall each zone received. The diversity and abundance of plant species varied from zone to zone, due to the precipitation differences, but nine of the 11 herbivore species were found in all three zones. The researchers were able to collect fresh feces samples from species ranging from African elephants (Loxodonta africana) and Angolan giraffes (Giraffa camelopardalis angolensis) to wildebeests, two species of zebra and a variety of antelope species.

The research team used DNA extraction and sequencing to identify what kinds of bacteria were present in the feces, which gave them information about the types and abundance of bacteria present in the gut microbiome of each animal.

“We ended up with 312 fecal samples across the 11 species, which gave us a wealth of microbiome data, and our analysis gave us a deeper understanding of the variables that can influence these microbial ecosystems,” says Rylee Jensen, first author of the paper and a recent master’s graduate from Northern Michigan University.

“One of the most interesting findings was that there were five types of bacteria that served as environmental indicators,” Jensen says. “Specifically, the relative abundance of these five microbes varied in a predictable way from zone to zone. All of these microbes are known for either breaking down lipids, breaking fiber down into nutrients animals can digest, or both. This is interesting because these environmental indicators could be key for helping us monitor environmental changes and how animal species are adapting to those changes.”

“Also, one of these environmental indicators is an entire phylum of bacteria that has previously been identified in the gut microbiome of camels,” McKenney says. “Camels are herbivores, but they are not closely related to any of the species we surveyed in this study, so to find that phylum here suggests it is a particularly robust indicator of environmental conditions in places where water is at a premium.”

The researchers also found a range of microbial differences that could be attributed to biological sex and gut morphology differences across species. However, there were some interesting findings involving the elephants.

“Elephants had two types of ‘core’ microbes – meaning these microbes were found in more than half of elephant samples – that were uncommon in the other species,” Jensen says. “This is likely due to the fact that elephants eat a wider variety of plant materials than the other species. This stood out because we found 22 types of core bacteria overall, and 20 of those types of bacteria were core bacteria for multiple species – but elephants hosted the only two types of core bacteria that were not common in other species. This highlights the role that feeding behavior and environment play on shaping the gut microbiome.”

“We’re excited about this work, in part, because we were able to collect high-quality samples from species in a region that had not previously been sampled for gut microbiome studies, and we got very fine resolution data,” says Diana Lafferty, co-author of the paper and an associate professor of biology at Northern Michigan.

“This is a level of detail and data quality that is often only achieved under captive or clinical conditions,” McKenney says.

“And we’ve essentially established a baseline that can be used to help us understand any changes we see in these species in this region,” Lafferty says. “That’s particularly important given the critical role that many of these species play in these ecosystems and the critical role gut microbiomes play in animal health.”

The paper, “Interspecific variation in gut microbiome diversity across the Etosha National Park herbivore community,” appears in the journal PLOS One. The paper was co-authored by Claudine Cloete, chief conservation scientist at Etosha Ecological Institute; James Beasley, the Terrell Distinguished Professor of Wildlife Management at the University of Georgia; and Madeline Melton, a Ph.D. student at UGA.

A study of elephants, giraffes and other wildlife in Namibia’s Etosha National Park underscores the ways in which the environment, biological sex, and anatomical distinctions can drive variation in the gut microbiomes across plant-eating species. Because the gut microbiome plays a critical role in animal health, the work can be used to inform conservation efforts. This photo shows an elephant and zebra in Etosha.

Credit

James C. Beasley