Meeting Abstract
Wild primates face grave conservation challenges, with habitat loss and climate change predicted to cause mass extinctions in the coming decades. We apply knowledge from ecophysiology research to address management efforts in tropical mantled howling monkeys (Alouatta palliata). Body mass data spanning ~40 years shows that animals are heavier in riparian compared to drier upland habitats, and exhibit habitat- and sex-specific seasonal shifts in weight. Precipitation increased over these years, with male, but not female, weights also increasing. Collectively, we infer significant, sex-specific impacts of environmental conditions on howler morphology. Jaw-muscle electromyograms from free-ranging animals demonstrate howlers modulate bite size or other behavioral parameters in response to seasonal or longer-term changes in food material properties. Thermoregulation studies indicate that howlers buffer the direct effects of rising temperatures by using cool nighttime refugia and exploit spatial heterogeneity in their habitat to navigate changing thermal pressures. These lines of evidence cumulatively indicate howlers’ use of physiological and behavioral mechanisms to adjust to temperature and rainfall changes. While habitat loss in the tropics is unlikely to abate, ensuring that forest fragments are suitably large with dynamic structures, as well as high connectivity between fragments, may aid howlers’ survival.
