As global climate change results in increasingly extreme temperatures, behavioral thermoregulation is one avenue by which species may adjust. Changes in activity patterns in response to temperature have been observed in a number of mammals, but have rarely been investigated in humid forested habitats. We examined the relationship between activity patterns and microclimate temperatures for white-lipped peccaries (Tayassu pecari), a mid-sized forest-dwelling ungulate and ecosystem engineer. Our objective was to determine whether an inverse relationship exists between temperature and activity. Our study areas were in two distinct Brazilian biomes, the Cerrado and the Pantanal, in the state of Mato Grosso do Sul, Brazil. From July 2013 to November 2016, we monitored 26 white-lipped peccaries fitted with GPS collars that included 2-axes accelerometers and temperature sensors. We used mixed-effect logistic regression models to relate temperature to the probability of peccaries being active vs. inactive.
Results/Conclusions
White-lipped peccaries were primarily diurnal and displayed peaks of activity at around 9 am and 6 pm. Total time spent active did not vary seasonally. White-lipped peccaries were significantly less likely to be active as temperatures increased, with the probability of activity falling to < 11% in both biomes once temperatures reached 40 ºC. Hourly temperature patterns from the collars did not fully conform to hourly patterns from external temperature sensors, suggesting peccaries may behaviorally adjust to locate optimal microclimates. Our findings indicate that white-lipped peccaries are likely to be adversely impacted by rising temperatures, through being forced to reduce foraging time. White-lipped peccaries in Southwestern Brazil, already under stress due to habitat fragmentation, are likely to be especially vulnerable to climate change.