Body temperature patterns in black-tailed prairie dogs in the field

Abstract

Body temperatures (T_b) of black-tailed prairie dogs (Cynomys ludovicianus) were monitored in the field for 1 year. A daily T_b rhythm was evident during all months that animals were monitored. Diurnal high T_b was always greater than nocturnal low T_b. An annual T_b pattern was evident with summer T_b > winter T_b. The maximum range in T_b over the year was 5.8 °C, between August diurnal T_b (39.3 °C) and January nocturnal T_b (33.5 °C). The greatest difference between average high and low T_b in 1 month occurred in January (2.8 °C). Torpor was never observed. The lowest recorded T_b in any individual animal was 31.0 °C during nighttime hours in January. Males exhibited higher T_b than females at all hours during the prebreeding period in January, while females showed greater T_b than males during the breeding period in February for 15 of 24 h. Significant differences in T_b were not observed between males and females at other times of the year. The daily and annual T_b patterns observed result in energy and water savings.