Investigating the Prevalence of Phytoestrogens In the Diet of Propithecus edwardsi
Savannah S Stark
Committee: Dana Emmert, Jeff Holmes, Langdon Martin
Phytoestrogens are naturally occurring estrogenic compounds produced by plants, and are considered endocrine-disrupting compounds. Understanding the role of phytoestrogens in the diet of primates is important for conservation and primate ecology. Madagascar includes many endemic plant species in families known to contain phytoestrogens, which makes the diet of folivorous and frugivorous lemurs of particular interest. This study conducted continuous focal sampling with Propithecus edwardsi (Milne-Edwards’ sifaka) focusing on diet and feeding behavior. Phytoestrogen-containing plant species were predicted to simulate the potential influence of estrogenic compounds on primate behavior and conservation efforts. Populations at two fragmented forest sites, Sahamalaotra and Talatakely, were observed. Lemurs at the site with greater anthropogenic disturbance, Sahamalaotra, were significantly more likely to feed on the predicted estrogenic plants compared to Talatakely, a site with intermediate anthropogenic disturbance.
From longitudinal phenology plant data, seasonality is supported for the abundance of estrogenic young leaves, despite the variance caused by unpredictable tropical weather. The resulting high possible prevalence of phytoestrogens in the diet of P. edwardsi suggests a need for future research using chemical analysis to confirm and quantify estrogenic compounds in the plant species. In addition, more in-depth research is needed to explore the influences of phytoestrogens on behavior and possible endocrine disruption. The high prevalence of phytoestrogen-producing plants in the diet of P. edwardsi suggests a need to quantify estrogenic compounds in the plant species they consume, as well as to explore the influences of phytoestrogens on lemur behavior and physiology.