VARIAÇÃO SAZONAL DA TEMPERATURA CORPÓREA NO LAGARTO TEIÚ, Tupinambis merianae (SQUAMATA, LACERTILIA, TEIIDAE)
2005; Linguagem: Inglês
ISSN
2639-6459
Autores Tópico(s)Species Distribution and Climate Change
ResumoIn order to obtain a profile of the seasonal and daily variation of the body temperature (Tc) of the tegu lizard, Tupinambis merianae, TidBit electronic data loggers (temperature probes) were surgically implanted in eight adult individuals. The lizards were kept in outdoor pens and monitored over a one year period. Tegu s body temperature showed seasonal and daily variations, which were related to the changes in the temperatures of the microhabitats (sun, shade, and burrow) and, possibly, to changes in heating and cooling rates. The daily average Tc followed a circadian rhythm characterized by lowest temperatures occurring at dawn, then temperature rapidly increases from soon after sunrise until noon, Tc is then maintained in high levels until late afternoon (~16h) when the lizards stop activity, retreat to the burrow, and let body temperature to drop. The mean Tc experienced by the tegus during activity at the warm season (August/December) was 33.6 C ± 1,4 C. During the active season, the heating rate of the lizards during the morning was five times greater than the cooling rate experienced during the night. As a result, tegus seems to be able to maintain their Tc above the temperature of the burrow and of the shade along the night time. With declining air temperatures towards the end of autumn, tegus enter their burrows, goes into dormancy, and the circadian rhythm in Tc become less prominent. During this season, Tc followed passively the variation of the burrow s temperature.
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