SAUROPHAGY AND CANNIBALISM IN TWO SPECIES OF LIZARDS IN SAN JUAN, ARGENTINA

GRACIELA BLANCO; JUAN CARLOS ACOSTA; ANA VICTORICA; GABRIEL CASTILLO; RODRIGO NIEVA; LIA PIAGGIO

Congreso; CUYO BIOLOGY SOCIETY; 2010

Saurophagy and cannibalism have been reported in lizards, eitherby chance discoveries or through behavioral studies. Although cannibalismhas been studied extensively in vertebrates, it is unclearto what extent it would be beneficial in reptiles. However, thereare studies that consider cannibalism one of the main causes ofhatchling mortality. Cnemidophorus longicauda and Homonotaunderwoodi inhabit the Monte desert (San Juan). During a diet studyof both species (samples collected by pitfall traps), two cases ofintraspecific predation were recorded in C. longicauda: adult males,snout vent long (SVL): (58 and 62mm) registered juvenile prey(SVL: 17-18mm). On the other hand, a female (SVL: 48mm) andtwo adult males (SVL: 47.5 and 47mm) H. underwoodi presentedin their diet Liolaemus darwinii juvenile individuals. This latterfinding is the first record of interspecific predation among geckonidlizards in Argentina. Reports of cannibalism in teiids from SouthAmerica are rare, and limited to intraspecific predation cases registeredin Callopistes palluma from Chile. We consider cannibalismas an atypical activity, possibly caused by overcrowding stress,or simply by accidental or opportunistic feeding.