Effects of parasitism on antipredatory responses and defensive behaviors in the subterranean rodent Ctenomys talarum

Abstract

Predation represents an important evolutionary force shaping specific adaptations. Prey organisms present behavioral adaptations that allow them to recognize, avoid, and defend themselves from their predators. In addition to predation, there is a growing consensus about the role of parasitism in the structuring of biological communities. In vertebrates, the effects on hosts include changes in daily activity, feeding, mate selection, reproduction, and modifications in responses to environmental stimuli. These behavioral variations can benefit the parasite (parasitic manipulation), benefit the host, or appear as a side effect of the infection. We evaluated the influence of parasitism on the behavioral and physiological responses of the tuco-tucos of the Talas (Ctenomys talarum Thomas, 1898) to predator cues. We found that individuals exposed to cat odors and immobilization entered less often and spent less time in the transparent arms of elevated maze, exhibiting a preference for protected areas (anxiogenic response). Additionally, we evaluated if the presence of parasites affected antipredatory behaviors in C. talarum (naturally parasitized, deparasitized, or inoculated with Eimeria sp.). We did not find differences among the groups with regards to responses to predator cues. Therefore, while exposure to predator cues triggered a stress response, the manipulation of parasite loads did not modify homeostasis under these experimental conditions.