RAPID: Primate stress and survival during a strong El Nino event

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

Some studies have shown that high levels of stress hormones in animals are linked to lower reproductive success and survival ("fitness"). Other studies have found that higher stress hormone levels may be beneficial. In wild animal populations it is often hard to measure fitness and correct for other factors that affect hormone levels. This RAPID project will support immediate collection of stress and survival data for several capuchin monkey groups in Costa Rica. These monkeys are currently experiencing the environmental effects of a strong El Niño climate pattern. The opportunity to study a well-monitored monkey population during a stress event (El Niño) that affects all individuals is rare. The project will provide new data on how an individual's past and present hormone levels relate to their fitness. The researchers support graduate training of individuals from underrepresented groups in the STEM sciences. The project also includes science outreach activities in Costa Rica and the United States, and primate conservation efforts. This project will test the cort-fitness hypothesis, which suggests that higher glucocorticoid hormone levels will be associated with reduced fitness. Currently, a very strong El Niño event is causing unprecedented mortality among a habituated, well-known population of white-faced capuchin monkeys (Cebus capucinus) at Lomas Barbudal in Costa Rica. This event presents the opportunity to test whether elevated glucocorticoids increase or decrease survival in wild capuchin monkeys subjected to a catastrophic stressor that affects all individuals. Longitudinal behavioral and fitness data and fecal measures of glucocorticoids will allow for an individual-level approach, correction for several other variables known to affect glucocorticoids in wild primates, consideration of past and present hormone levels for the same individual and in comparison with others, and assessment of infant mortality and maternal hormone levels.