Activity patterns of avian species are clearly influenced by abiotic factors as well as the multiple biotic factors. Some of these abiotic factors, such as the impact of wind speed and direction on neo-tropical migrants, are relatively well understood. Others have not been as well studied. For example, the relationship between temperature and avian activity throughout the breeding season is poorly understood. Previous studies examining this question have only focused on temperature just before sunrise. Furthermore, the relationship between temperature and detectability has varied by species, in both the magnitude of its relationship, and its direction. The present study uses data from point counts conducted for forty-nine summer resident species at Texas Tech University’s Llano River Field Station in Junction, Texas during June-August of 2018. Temperature and wind speed data were taken from a Mesonet station on site. The confounding variables time of day and the time relative to sunrise, and two-way interactions between sunrise and the abiotic factors of interest, temperature and wind speed, were included in the analysis.
Results/Conclusions
Temperature alone was associated with abundance in 11 of 49 species. In three of these, this association was positive and in eight it was negative. Wind speed alone was also associated with abundance in 11 of 49 species. In two of these, this association was positive, and in nine it was negative. When confounding variables were considered, Akaike’s Information Criteria indicated that the best model included temperature for 13 species and wind speed for 19 species. Additionally, significant interactions involving temperature or wind speed, or between the two were part of the best model according to Akaike’s Information Criteria in 13 species. An interaction between temperature and wind speed specifically was present in seven species. This study breaks ground in examining temperature and wind speed together throughout the day, and throughout the season. One important implication of these results is that more frequent heat waves associated with climate change could have an especially large impact on species that exhibited increased abundance throughout the study period, but decreased abundance with higher temperatures.