Interactions of diet and behavior in a death-feigning snake (Heterodon nasicus)

Abstract

Studies of animal behavior in captivity are limited in their ability to explain the
influence of a natural environment on behavioral ecology. Defensive behaviors vary among
individual animals, between sexes and with age, as well as with other less well-known
factors. The toxin-rich diet of many toad-eating snakes might enable or cause their passive
terminal defensive behavior of death-feigning. I videotaped death-feigning behavior in wild
Plains Hog-Nosed Snakes (Heterodon nasicus) subjected to standardized harassment. Using
stable isotopes, I also described the diet of the same individuals subjected to behavioral
analysis (n = 40). Heterodon had broader diets than other snakes at the study site. Both diet
and behavior differed between sexes and age classes. Male H. nasicus death-feigned for
longer than females, but initiated death-feigning later. Female H. nasicus had more
specialized diets than males; adults of both sexes consumed mostly turtle eggs during the
study period, while juveniles fed on Six-lined Racerunners and their eggs. Residual
individual variation in behavior might be attributable to diet or to other factors. Further
research is necessary to elucidate the complex relationship between diet and behavior in
toad-eating snakes.

Date of Award	2011
Original language	American English
Awarding Institution	Eastern Illinois University
Supervisor	Stephen Mullin (Supervisor)