Will primates become extinct? 7 experts explain the looming threat

Research suggests 66 percent of primate species are vulnerable, endangered, or critically endangered and 85 percent of primate species are in decline.

In many ways, humans are largely to blame. While deforestation and hunting threaten specific wild primates, a rapidly changing climate threatens nearly 40 percent of all primate species.

A recent study published in the journal Conservation Physiology contributes to a concept edging dangerously close to becoming a reality: the extinction of non-human primates.

This specific study focuses on how female bushbabies respond to a changing environment. While they may look more like wide-eyed chinchillas than gorillas, these animals are nocturnal primates.

“Although this species is quite resilient, all species will have their limitations and with the progression of climate change and the shrinking of their natural habitat, this will definitely be to their detriment,” lead author Channen Long, a researcher at the University of Pretoria, tells Inverse.

What’s new — The October 2021 study focuses on the hormonal response of female thick-tailed greater galagos (Otolemur crassicaudatus) — a type of bushbaby — to their quickly changing environment.

The study focuses on a species of bushbaby which lives in South Africa’s Soutpansberg Mountains. While these animals are not at high risk of extinction at the moment, they do face threats from humans such as fallen power lines and automobiles. Furthermore, these new findings suggest they may not be able to adapt as well to future climate change as scientists would hope.

After collecting fecal samples from the primates and measuring hormone levels, the researchers discovered female bushbabies are experiencing more stress than males in response to seasonal changes — especially around the time when they nurse their young.

As a result of ongoing seasonal weather changes due to climate change, bushbabies “will need to adjust their physiological capabilities to withstand hotter and drier summers,” Long says.

“The change in weather will start affecting food availability which will have a serious impact on reproductive success and, inevitably, affect their own survival.”

Are primates becoming extinct?

In light of this new report, Inverse spoke with six other primatologists about:

• The scope of the primate extinction threat
• The factors driving extinction
• The influence of climate crisis and whether primates can adapt
• How humans can protect our closest living relatives

Here these experts describe in their own words their prediction for primates. These interviews have been lightly edited for brevity.

Michelle L. Sauther, co-author of the bushbaby study and co-director of the Nocturnal Primate Biology Project and the Beza Mahafaly Lemur Biology Project

In terms of primary drivers of primate extinction, some of the major factors are all tied to human behavior and stressors.

So for example, in Madagascar, where I have worked on lemurs for decades, lemur habitat destruction for farming combines with droughts and other weather-related factors that negatively impact lemur populations, reducing food resources and making it difficult for females to produce nutritional milk for their infants and to find adequate weaning food for their babies.

In terms of adapting to a warming climate, there is published research that the bushbaby we studied, Otolemur crassicaudatus, does poorly at very high temperatures as this overwhelms their ability to effectively thermoregulate. So in addition to affecting food resources, global warming will challenge primates’ ability to adequately maintain their body temperatures.

“Primate extinction is tied especially to human poverty.”

Most primates have adapted to a particular climate type and live in the tropics where climate has been predictable. These types of habitats are especially vulnerable to changes in both climate as well as human-induced changes, such as clear-cutting forests. Major changes in the tropical geographical regions will have especially negative consequences on the highest number of species and will be most dramatically felt.

Primate extinction is tied especially to human poverty. When local people living in primate habitats cannot have decent water, food, and a stable economy this will put pressure on them to carry out desperate acts to feed their children. They have to be part of the solution and not always seen as “bad agents.”

As highlighted recently at the Glasgow meetings, Western nations have created many of the negative issues regarding climate change in poorer countries. This also includes creating pressure on poorer countries that have primates to develop economically unsound strategies that include destroying their own forests and other habitats that primates depend on.

Paul A. Garber and Alejandro Estrada, primate conservation researchers and co-authors on a 2017 article on primate extinction.

Much has changed over the past 4 to 5 years, and none of the changes benefit primate population persistence. Deforestation of tropical rainforest continues, as large agribusiness companies and governments continue to convert natural habitats to monocultures and fragmented and polluted landscapes for products that are consumed by people in a smaller number of rich nations.

In addition, Indigenous Peoples, who have used their homelands sustainably for millennia, are being forced off these lands by colonists, governments, the creation of roads and other infrastructure, and legal and illegal mining. Climate change also is contributing to the primate extinction crisis.

Perhaps the most startling statistic is that in 2017, when we published our paper, 55 percent of primate species were listed as vulnerable, endangered, or critically endangered, and 75 percent had declining populations.

“Primates are like the canary in the coal mine.”

Today, approximately 66 percent of primate species are listed as vulnerable, endangered, or critically endangered and 85 percent of species have declining populations.

We should care because primates are our closest biological relatives. They play a fundamental role in the belief systems and cosmology of many religions, and they contribute to ecological processes in forest ecosystems such as pollination, seed dispersal, and predator-prey relationships that promote carbon sequestration. Primates are an important renewable food resource for many Indigenous and rural Peoples.

Primates are like the canary in the coal mine. If we continue to destroy and degrade natural ecosystems, and those ecosystems become unsuitable for non-human primates, then not long after, those same habitats will become unsuitable for human primates.

Catherine Hobaiter, a researcher in St. Andrews’ School of Psychology & Neuroscience who studies wild chimpanzees’ social behavior

It is not only possible but, sadly, very likely that some species will be functionally extinct due to habitat loss and other threats.

In my case, I work with great apes — mostly chimpanzees. I don't think that they will be extinct as a species in the near future, although with the current rate of decline, it is a serious worry in the medium term. But I am sure that we will lose populations and communities of chimpanzees.

I study ape minds — what makes them, them. Chimpanzees, like many primates, are individuals — each with their own history and local culture. Population size is not the only thing that matters — when you lose a community of chimpanzees, you lose their local culture, something that can never be replaced even if other individuals are protected.

What harms them harms us. Take one example: The current pandemic is almost certainly the result of a disease that was endemic in a wild species jumping to humans — those jumps occur more frequently as we interact with more wild species by taking over previously wild spaces.

Sadly, the economic pressures created by the pandemic mean that many communities fall back on natural resources — for example game hunting in forests. The conditions from this pandemic make the next one more likely.

Michael Huffman, associate professor at Kyoto University’s Primate Research Institute

The extinction of any species should be of grave concern for everyone. I have not directly witnessed the extinction of a local population that I was studying, but of the species I have studied, several of them currently live in habitats where pressure from human encroachment is great.

Increased interactions with humans bring greater stress into their daily lives. The animals are forced to change their behavior and food resources as a result of habitat loss, often at the risk of contracting human diseases, or passing their diseases onto the humans now sharing that environment.

“Primates don't need us, we need them.”

On the other hand, some species like macaques in Asia, often live in close proximity to humans. They tend to be better off, but with an increase in human-primate conflict over mutually depended upon resources, primates lose out if human livelihoods are threatened.

However, the effects of climate change can impact the lives of primates, even where human interference is less severe. Some primates can adapt fairly well to climate change in the short term, but others are more vulnerable if they have a very specialized diet and particular lifestyle needs. We do not know about the impact this will have over the long term yet. Over time, some species may be stressed to a point of no return. We just don't know enough yet in some cases to say how devastating those impacts might be.

Primates play important roles in ecosystem management. Primates don't need us, we need them.

There is always hope if we act smartly, carefully, and quickly in ways to curb climate change in the long run and reduce habitat destruction in the short term.

Rahel K. Brügger, a researcher at the University of Zurich who studies the evolution of human traits in primates

I am definitively concerned about the possible and likely extinction of many primates in the near future.

First of all, the loss of primate species means a loss of biodiversity and this means a disruption to the ecosystems that primates are a part of. Primates are parts of food webs as prey and predators, and many primates function as pollinators — this means they are a really important part of ecosystem structure and function.

This is already a big concern, but for me as a researcher and anthropologist interested in the evolution of human traits, primates are also a really important model species that can help to shed light on human behavior and cognition, cooperation, or language. Not being able to learn more about these amazing animals and their behavior is a great loss.

To stop the extinction of primates, global and local policies and laws need to prioritize conservation efforts. But this does not mean that my personal choices as a consumer — prioritizing plant-based food, thinking about how and where we travel to, avoiding palm oil, choosing to support NGOs with conservation efforts — do not have any impact at all.

As researchers, we also have the additional role of continuously educating our immediate social environment about issues, such as the illegal pet trade and raising awareness of the negative impacts of posting [and reposting] pictures and videos with primates as pets or wild primates in general.