Térmitas e formigas como recursos perenes para a comunidade de lagartos em um ecossistema de caatinga

Abstract

Seasonally dry tropical forests occur from northwestern Mexico to northern Argentina and southwestern Brazil and are characterized by the presence of a water deficit that is the result of an uneven distribution of precipitation throughout the year, and may have several months of drought in the which one that occurs can reach less than 100 mm. This lack of rainfall in a few months influences plant biomass and the animal abundance and activities, occurring in fluctuations in the supply of food resources to sources of higher trophic levels. This study aimed to find out whether termites and ants are perennial resources for the lizard community present in the Caatinga, a type of seasonally dry tropical forest in Brazil. Lizards were collected between January 2008 and December 2009, through active captures and pitfall traps with directed fences. Food contents were analyzed by extracting the stomachs of 785 lizards. A total of 5830 items were registered, being classified into 35 food categories. Social insects represented 44.7% of the total, with Isoptera and Formicidae being the food categories that were most present in the stomachs of lizards. Social insects represent a perennial resource for lizards throughout the year, being consumed in greater quantities during the dry period, when resources are absent or less available. It was observed that, in addition to food availability, foraging also influences the consumption of social insects, with active foraging lizards increased consumption of social insects type when compared to the sit-and-wait lizards. Regarding the species, not all had a significant variation in consumption, but it was seen that all species had ingestion of social insects in the drought and some did not consume in the rainy season, reinforcing once again the importance of these insects in mitigating the effects of drought for populations at higher trophic levels and that with the increase in the availability of food resources during the rainy season, the consumption of termites and ants by lizards may decrease.