Seasonal physiological responses in the greater thick-tailed galago (Otolemur crassicaudatus)

Abstract

Primate populations over the globe are facing declines as a result of several factors including climate change. It has become imperative to gain further insight into how primate species respond to these changes in weather to ensure appropriate conservation approaches. For this study, I chose to monitor the physiological changes of a population of greater thick-tailed galagos (O. crassicaudatus) residing in a highly seasonal, temperate environment. Research of this strepsirrhine species has been lacking for over two decades and the scientific community is unaware how they respond to seasonal weather changes. In this study, we assessed their glucocorticoid and thyroid hormone levels to monitor their hormonal responses, gut microflora, and metabolite profiles associated with changes in temperature and food availability. We successfully validated the immunoassays necessary to measure hormone metabolites in this species. The results revealed an increase in hormone levels during the summer season which may be caused by an increase in energy expenditure as food availability and temperatures increase. Furthermore, lactating females during this time require additional energy and nutrition to sustain themselves and their offspring. The results of the metabolite analyses indicate these concentrations were affected by changes in diet. However, it appears the dominant microflora and metabolic pathways adapt to seasonal fluctuations of nutrient intake to ensure the body receives the essential amino acids needed for ATP generation. Overall, this project has given further information into the mechanisms undertaken by this species during times of low food availability and will assist in future primate conservation.