Thermal biology of the tortoise Chelonoidis chilensis: determining the activity pattern and estimating selected and critical maximum temperaturas

BUTELER CANDELA; LABAQUE, M.C,; GERARDO C. LEYNAUD

Herpetological Conservation and Biology

Herpetological Conservation and Biology (United States)

Año: 2022 vol. 17 p. 111 - 121

1931-7603

Ectothermic animals depend on environmental temperature to regulate their body temperature. Chelonoidis chilensis is a common Chaco tortoise widespread in South America; however, its populations are threatened mainly because of the pet trade. We described the activity pattern of C. chilensis relative to the environmental temperature under semi-controlled conditions in a Zoo enclosure and estimated thermal parameters under controlled laboratory conditions: selected temperature (TSel) and critical maximum temperature (CTMax) among sex and size indicators. In the enclosure, 81 % of the observations were from inactive tortoises and 19 % from active tortoises. Tortoises were active over a wide thermal range (12.0-38.0 ºC) and TSel was 34.4 ± 0.3 °C (mean ± S.E.) with no significant differences among size or between sexes. Heavier tortoises spent more time at the lowest temperature than did lighter ones (Chi square test; p