Habitat use by the South‐American rattlesnake (Crotalus durissus) in south‐eastern Brazil

Abstract

Habitat use affects food intake, reproductive fitness and body temperature control in reptiles. Habitat use depends on both the characteristics of the animal and the environmental heterogeneity. In this study we investigated habitat use in a population of the South‐American rattlesnake, Crotalus durissus, in a cerrado (the Brazilian savanna) remnant, in south‐eastern Brazil. In general, snakes appeared to be thermal generalists. However, they showed substrate temperature preferences in the rainy season, when they selected colder substrates during the day and warmer substrates at night. Individuals were predominantly active on the surface and more frequently found under bushes. Furthermore, in general, the principal component analysis results indicate that rattlesnakes are generalists regarding the microhabitat variables examined in this study. These habitat characteristics, associated with a low thermal selectivity, indicate that rattlesnakes are able to colonize deforested areas where shade occurrence and vegetation cover are similar to those in the cerrado.

Keywords:

• Crotalus durissus
• habitat use
• radio‐telemetry
• ecology

Acknowledgements

We are grateful to Otávio A.V. Marques; Paulo Hartmann, Ricardo J. Sawaya and Selma M. Almeida‐Santos for critically reading earlier versions of the manuscript. The study was conduced with field assistance of several biologists, especially Victor Vetorazzo. Denise Zancheta permitted the access to the Ecological Station of Itirapina. We also thank FAPESP (proc. n. 00/12339‐2, 01/13341‐3, 06/58011‐4) and CNPq (proc. n. 470621/2003‐6) for financial support.