Manejo alimentar de Crotalus durissus em cativeiro

Abstract

The Viperidae family comprises a monophyletic group of more than 329 snake species widespread around the world. One of its genera is Crotalus, the rattlesnakes. The species Crotalus durissus adopt the ambush strategy to hunt their prey, that is, the snake remains coiled and in an active posture at the hunting site and strikes only when passing a possible prey. An apropriate feeding management for snakes in captivity should consider factors such as the size of the food and the control of environmental variables, as they directly influence the acceptance or refusal of food by the snake. According to public policies, snakes kept in facilities of institutions of teaching or scientific research must be fed by rodents previously euthanized. The Serpentarium of the Butantan Institute is considered a semi-extensive captivity where the animals are exposed to conditions that resemble their natural habitat.Until 2016, the animals were fed with live rodents in the serpentarium. From 2017 until current days, euthanized rodents are offered in the bioterium, an intensive captivity where the animals remain individualized in plastic boxes, and the temperature and humidity are controlled according to the animal's needs. The objective of this work was to verify if the change in the feeding management of the rattlesnakes had an influence on the acceptance or rejection of food by the snakes. For this, we analyzed the routine feeding records of 11 animals within a period of two years before and after the change of management. We recorded the number of times food was offered, accepted and rejected for each snake in each type of treatment. There was no significant difference between the two food routines tested. However, the mean value of food acceptance was higher when the rodent was offered euthanized, and the mean value of food rejection was higher when the rodent was offered alive. Thus, we discussed that the small increase in acceptance and the small decrease in the rejection of food by snakes may have occurred due to the combination of factors such as greater control of environmental variables and reduced stress. This study shows that there is no significant difference in the acceptance and rejection of food by the snake comparing two treatments of food management. However, even with asmall sample number, there is still a tendency to better use when the prey is offered euthanized in intensive captivity.