The extent to which animals may compensate for rising temperatures through behavioral thermoregulation is an important unknown in predicting responses to climate change. Flexibility in temporal activity in particular may be an important factor in determining species’ vulnerability. In this study, we examine whether the white-lipped peccary, a predominantly diurnal Neotropical mammal, shifts its temporal activity and microclimate selection in response to daily temperature variation in the Pantanal biome of Brazil. From November 2021 to October 2022, we deployed camera traps and microclimate data loggers to record white-lipped peccary activity and air temperature on a fine spatiotemporal scale. We found that the percentage of peccary activity that is nocturnal increased with maximum daily temperature at a rate of 3.7% per 1°C past a threshold of 31.2°C, and increased with maximum daily wet-bulb temperature at a rate of 4.7% per 1°C past a threshold of 24.9°C. The afternoon period (i.e. solar noon to sunset) went from having the highest frequency of peccary activity at the lower end of our observed temperature range to having the lowest frequency of activity at the higher end. We did not find evidence of microclimate selection. Our findings indicate that white-lipped peccaries in the Pantanal demonstrate substantial behavioral flexibility in their response to high temperatures, which may help to buffer them against the impact of rising temperatures caused by climate change.

This dataset includes all data from the microclimate date loggers. Camera trap records can be accessed through Wildlife Insights.

Paired camera traps and microclimate data loggers were deployed within forest patches at Pousada Aguapé with high levels of white-lipped peccary activity, as determined by the presence of tracks and chewed-up palm seeds, as well as detection of peccaries within two weeks of the initial camera placement. This methodology was chosen instead of using randomly selected sites because the objective of the study was to examine environmentally driven shifts in temporal activity and microclimate selection, and so it was necessary to ensure all sites were being regularly frequented by peccaries. The sites chosen were all within closed forest, as previous research conducted at this site and in the surrounding region, in which GPS collars were deployed on white-lipped peccaries, found that peccaries only enter open areas for brief periods in order to cross between forest patches (Jorge et al., 2021). The data loggers recorded air temperature and relative humidity, and were set to take readings every 30 minutes. All loggers were tied to the branches at a height of approximately 0.5 m in heavily shaded locations to ensure that they would not be exposed to direct sunlight. The accuracy of the data loggers used was 0.3 °C for air temperature and 2.25% for relative humidity (LASCAR electronics, 2021). Twenty-five cameras and 22 data loggers (of which two were damaged or lost) were deployed at a total of 40 sites over the course of the study period (Appendix S2). Cameras and loggers were initially placed between November 12, 2021 and December 1, 2021. Data was retrieved and SD cards and batteries were replaced from February 9 to 12, 2022.  Cameras and loggers were checked again and new sites added between June 11 and 28, 2022. Final data retrieval was conducted from October 14 to October 16, 2022. We used Browning Strike Force HD Pro X camera traps (Browning, 2022) and LASCAR EasyLog EL-USB-2 data-loggers (LASCAR electronics, 2021).