Climate change has biggest impact on smallest primates, says CU Boulder professor – Boulder Daily Camera

A southern lesser galago clings to a tree at night at the Lajuma Research Center in South Africa. (Téo Novel-Jandet/University of Colorado Boulder)

A team of researchers, led by primatologist Michelle Sauther of the University of Colorado at Boulder, found that the consequences of climate change are disproportionately affecting the smallest primates after two different species’ busy breeding families.

The team’s research took them on 75 night walks through the Lajuma Research Center in South Africa’s Soutpansberg Mountains from July 2017 to June 2018. On these trips, the team, which also included researchers from the University of Pretoria and the University of Venda in South Africa. and the University of Burgundy in France, looked for two different types of primates: the southern lesser galago and the greater thick-tailed galago, also known as the bushbaby.

These primates are remarkably similar on paper: they are both classified as small, nocturnal mammals and live almost their entire lives in trees. They both hunt for insects at night and lick gum from the acacia trees. One of the only ways they differ is their body size: Greater galagos are the size of large cats, while lesser galagos are as small as squirrels and weigh less than a soda can.

“It’s like you’re comparing a gorilla and a monkey,” said Sauther, a professor in the Department of Anthropology at CU Boulder. “We’re talking about those kinds of differences.”

The team decided to study these two similar primates to explore an overlooked question in conservation: does body size affect how an animal adapts to extreme temperatures?

During their walks, the team discovered that the lesser galagos were out and about in the forest much more often than the greater galagos, braving extreme temperatures in a forest where annual temperatures can range from nearly zero degrees in the winter to 100 degrees Fahrenheit. in summer. . The lesser galagos also came out later in the evening and were found in all weather conditions.

Greater galagos, on the other hand, tended to wait out the harsh weather conditions and temperatures, and were more active earlier in the evening.

This relaxed attitude can be explained by the larger body size and slower metabolism of galagos, according to the study.

A smaller body mass requires more constant energy, meaning that lesser galagos needed to forage regardless of the time of night, temperature, or weather to gather enough food to get them through the next day. According to the study, the greater body mass of the greater galago may act as a buffer between active periods that allows them to be more selective when searching for food.

“What we found is that during very cold or very high temperatures, the smaller species just kept going… They can’t sit back like the larger species and choose and say, ‘Well, I’m going to go out, but it’s going to be during this period of time.’ time,’” Sauther said.

According to the study, the small size of lesser galagos and their need to feed even in the most extreme conditions disproportionately expose them to the effects of climate change.

“When you think about small primates or just small mammals, we tend to think that all small mammals are the same, but that’s not the case. “There is a huge variation in terms of body mass,” Sauther said. “So if you’re really small, rather than really big, climate change will affect you in a very different way.”

These findings arise as a result of a deliberate choice to focus on understudied primates. Because both species are nocturnal, it requires much more effort for humans to search for them and track their habits. The researchers used thermal imaging and documented the frequency of their encounters with each species.

“If you ever go out and walk at night, it seems strange to you. “There are reasons why people are afraid of the dark,” Sauther said. “So if you’re going to study these guys, orientation at night is difficult because, again, we’re so tied to the activity during the day.”

Sauther said studying overlooked primates like these galagos is important because uncovering vulnerabilities is an important part of conservation efforts.

“I have always studied underdog primates. “I don’t study chimpanzees or gorillas, I study them,” Sauther said. “It was really important to study these nocturnal primates because they are very understudied, and how are we going to know their conservation status if we don’t go out and study them, and see where they are?”

Now that the team’s data is available, the next steps are to partner with local researchers and see what can be done to help conserve these species, given new knowledge about their relationships to climate change.

“We are really interested in working with South African universities and have started to develop partnerships with them. And the main reason is to pass on (our knowledge)0 and collaborate with local researchers, and also to help facilitate teaching the next generation of scientists in South Africa,” Sauther said. “We hope to also have an intellectual exchange in terms of our students and their students working together on many of these projects to develop this more global approach.”

Read the study at link.springer.com/article/10.1007/s10764-024-00427-5