Poaching affects the behavior of endangered capuchin monkeys in Brazil’s biosphere reserves

Publicado em 21 junho 2021

Studies conducted in the Una Biosphere Reserve in Bahia, Brazil, show that the risk of predation has a significant impact on the behavior of golden-bellied capuchas in habitats with high hunting pressure. Sapajus xanthosternos They may even avoid areas that are rich in plant biomass and invertebrates, which are their main food sources.

Articles reporting the results of the study American Journal of Primatology..

“Many theories in the field of primatology assume that the pressure to find food is more important than the predatory pressure. In this study, where is the predatory pressure of una than where it is most abundant in food? We were able to show that it is more important in determining. Animals spend less time because they feel they are at high risk of predation in food-rich areas. Another very important. The point is that this risk is Natural predator Even by human predators, poachers. Because of the pressure of hunting, they spend less time in the places where the most food is available, “said Patricia Isar, the last author of the article. Isar is a professor of experimental psychology at the University of Sao Paulo Institute of Psychology (IP). -USP).

This study was part of a PhD research project by Priscila Suscke, the first author of this article. According to researchers, una includes three major types of vegetation: mature forests, secondary forests, and agroforestry systems called Kabruka, where cocoa trees introduced in place of understory vegetation thrive in the shade. Includes “habitat mosaic” primeval forest.

“Although food does not affect the use of the area, in these different forest landscape environments of the Una Biosphere Reserve, each environment provides different amounts of food and each poses a different level of risk. I will. [in terms of predation and poaching]”Analysis of the factors that influence the use of these three environments in monkeys has shown that the group has avoided areas with the highest food supply due to the risks involved,” Sasuke said.

This study was supported by FAPESP through the Sao Paulo Research Foundation-PhD. Suscke was awarded a scholarship and Izar was awarded a regular research grant. “All my research on primates over the last two decades has been basically funded by FAPESP, but with the support of other institutions,” Izar said.

To collect field data, Isar and three trained observers observed a group of 32-37 capuchin monkeys. They followed the group at the same time and began collecting data only when the accuracy of the agreement between the observers reached 85%. The training period was about 3 months. All observations were recorded using a GPS unit, so all reported outbreaks were georeferenced.

“When estimating the area that animals actually use for survival, we took into account all geographic reference points, including foraging and sleeping areas, as they were smaller than the area of ​​the protection unit.” Geographer Andrea Pressott explained. Professor of Geography and Earth Sciences at Salisbury University in the United States.

Researchers observed foraging behavior using fruits left in aluminum trays fixed to the ground and traps in the form of shallow holes that invertebrates could not fall and climb. ..

Non-feeding behaviors such as rest, travel, interaction with other monkeys, and surveillance were recorded every 15 minutes for each individual. To reflect risk perceptions, researchers focused on geo-referenced alert calls and alert behavior in each habitat. The animal’s response to the alert was the basis for analyzing the perceived predation risk and its effect on behavior.

“This study uses data collected on foraging behavior, predator response, and environmental interactions to be an objective measure of what is called absolute predation risk based on its environment, food supply, and density. We also cross-referenced with the number of predators in the area. “

Horror landscape

Presotto used field data to map five spatial predation risk variables. Hunting pressure, pressure from terrestrial or aerial predators, vigilance, silence, each associated with three forest environments. This so-called “landscape of fear” approach consists of visual models that help explain how fear can alter the use of areas by animals as they seek to reduce their vulnerability to predation. It has been.

“The intensity of each variable was calculated in GIS [geographic information system] Use the kernel density method to estimate the number of occurrences in a particular region. For example, whenever an aerial predator attack was observed, points were recorded using a GPS unit. The model told us where such an event happened most, “says Pressott.

Maps and statistical models created by Presotto to display predation risk variables confirmed the group’s first hypothesis. “Evidence of human hunting was the most abundant in Kaburka, but was also found in the transition zone between mature forests and secondary forests and the Kaburka region. In addition, monkeys are more frequent in Kaburka than the other two landscapes. The risk from terrestrial predators was highest in secondary forests, and was highest in caburka and mature and secondary forest areas from aerial predators, especially in transition zones. Monkeys were caburka and wide secondary. I was more vigilant in the forest area, “said Mount Pressot. Geographic reference database for topics.

Suscke says the reaction depends on the type of predator. “The important thing is the perception of predation risk, that is, how the prey perceives where in the landscape the risk of predation is low or high,” she said. “A refined analysis showed that different predators had different effects on prey perception and behavior, and we were able to create separate indicators for aerial predators, terrestrial predators, and poachers. We were able to demonstrate the importance of hunting. Determined the pattern of use of these monkeys in the area, and above all, the risk of hunting adversely affected the use of the area. “

Researchers are also studying capuchin monkeys in two locations: Fazenda Boavista (Piaui) and Carlos Botello State Park (Sao Paulo). “Because of comparative studies, monkeys in the Una Biosphere Reserve have shown a higher perception of predation risk for more frequent alarm behaviors such as silence and freezing, which appear to be hunting-specific. “Izar,” recalled that Omakizaru was naturally very noisy. “Our article points out yet another adverse effect of anthropic pressure on animal behavior.”

Monkeys are not pets

In the case of Suscke, this article also gives an idea of ​​public policy. “Poaching has a huge negative impact. Conservation units have been created over the years and this is a commendable policy, but our findings show the importance of proper monitoring to manage them properly. I’m showing, “she said. “Given the existence of entertaining hunting and poaching, it is also important to educate the general public because they opportunistically seek food and systematically buy and sell animals. Monkeys are pets. It is not uncommon to see them kept as. In such cases, poachers usually catch their mothers. Yellow-breasted captin is an endangered species and solves the problem. It is difficult to do and must be subject to stricter policies. “

Isar emphasizes that the list of wildlife that can be legally sold as pets recently published by the Brazilian National Environmental Council (CONAMA) is a threat to primates. “The pressure on them is so strong in Brazil that the Brazilian Primate Society has launched a campaign titled” Monkeys are not pets “. We know that legalization of commercial breeding of wildlife will lead to increased illegal trafficking of animals captured in their natural habitats, as commercial breeding animals are much more expensive. ” She said.

Researchers observe examples of cannibalism in wild white-faced capuchin monkeys

For more information:
Priscila Suscke et al, the role of hunting in the horrifying landscape of Sapajusxanthosternos in the Atlantic Forest of Brazil American Journal of Primatology (2021). DOI: 10.1002 / ajp.23243

Quote: Poaching is a biological reserve in Brazil acquired on June 21, 2021 from https: // (2021) Affects the behavior of endangered oysters (June 21)

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