BODY-TEMPERATURE, THERMAL TOLERANCE AND INFLUENCE OF TEMPERATURE ON SPRINT SPEED AND FOOD ASSIMILATION IN ADULT GRASS LIZARDS, TAKYDROMUS-SEPTENTRIONALIS

1. We studied in field and laboratory experiments several aspects of t he thermal biology of adult lacertid lizards (Takydromus septentrional is). 2. The selected body temperature and the critical thermal maximum averaged 30.0 and 42.3 degrees C, respectively; the critical thermal minimum of males and females averaged 3.9 and 5.9 degrees C, respectiv ely. 3. The lizards in May exhibited lower and more variable active bo dy temperatures than did the lizards in July, because of lower and mor e variable air and substrate temperatures in May. 4. The sprint speed generally increased with body temperature within the range of 17 to 32 degrees C and decreased at temperatures >32 degrees C. 5. Within the range of 26 to 36 degrees C, body temperature influenced food assimila tion primarily by affecting the food passage time, whereas it only sli ghtly affected the daily food consumption, the apparent digestive coef ficient and the assimilation efficiency. The food passage time decreas ed with increasing body temperature. Copyright (C) 1996.