Factors affecting the thermal behavior of the sand lizard Liolaemus wiegmannii in natural and modified grasslands of temperate coastal dunes from Argentina

BLOCK CAROLINA; STELLATELLI OSCAR; GARCÍA GERMÁN OSCAR; LAURA VEGA; ISACCH JUAN PABLO

JOURNAL OF THERMAL BIOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2013 vol. 38 p. 560 - 568

0306-4565

The present study describes and compares the thermal behavior of individuals of Liolaemus wiegmannii, in habiting patches of natural grasslandand modified patches with exotic trees of Acacia longifolia, by analyzing the factors affecting its behavior. Thermal behavior of L. wiegmannii was assessed by radiotracking 22 adult individuals in a coastal dune area from Argentina. In order to account for individual responses we analyzed the factors affecting thermal behavior using Generalized Linear Mixed Models. Thermal behavior of L. wiegmannii was mainly affected by the time of day and the substrate temperature. The individuals basking on baresand in the morning shifted to filtered sunlight during midday and to the shade of clump and erect stems and herbs during the afternoon. The individuas buried in sand when the substrate temperature was low and the wind speed was high. The use of sub-shrubsand shrubs could not be explained so lely by thermal factors. In natural L. wiegmannii regulated its body temperature by shuttling between microhabitats that provided them with different levels of exposure to sunlight during the day.However,in modified patches individuals varied in the choice of plants use dasshaded places to mitigate high microenvironmental temperature sand they were also more exposed to full shaded site sand less towarm sand to bask,which could have negative consequences for its thermalbiology.