Stress load along a gradient of human disturbance in two sympatric lemur species

• Applicants: Professor Dr. Peter M. Kappeler; Dr. Cornelia Kraus
• Subject Area: Animal Physiology and Biochemistry ; Anatomy and Physiology
• Term: from 2014 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 256175664

Because the HPA axis responds in the same way to social, physiological and ecological challenges, stress hormone levels are often used as an integrative indicator of health, whereby especially long-term (chronic) stress is associated with negative health outcomes. Within an on-going project on the conservation physiology of two closely-related lemur species, the fat-tailed dwarf lemur (Cheirogaleus medius), and the grey mouse lemur (Microcebus murinus), we here focus on the pivotal role of stress in mediating the sensitivity of these species to anthropogenic change. Hair provides a unique matrix for assessing long-term stress, because it integrates HPA activity over several weeks to months. Using hair cortisol levels, we will evaluate the hypothesis that the slow-living specialist C. medius is more sensitive to anthropogenic change than the fast-living generalist M. murinus by comparing stress loads along a gradient of human disturbance. To interpret our findings and to thus assess individual and population health more robustly, we will then evaluate the relationship between stress levels and two more indicators of health, body condition and parasite loads. Finally, we will test whether increased stress loads are indeed associated with decreased survival probabilities and quantify this relationship for the two study species. Combining sensitivity estimates with its demographic consequences in predictive population models provides a sound basis for conservation decisions.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Clemens Kirschbaum