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

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 response of Ctenomys talarum (Thomas 1898) to predator cues. We found that individuals exposed to cat odors and immobilization entered less often and stayed 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 tuco-tucos (naturally parasitized, deparasitized or inoculated with Eimeria sp.). We did not find differences among the groups as regards 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.

Personality underground: evidence of behavioral types in the solitary subterranean rodent Ctenomys talarum

Background Animal personalities have been studied in a wide variety of taxa, but among rodents, available studies are relatively scarce and have focused mainly on social species. In this study, we evaluated the existence of personality in the solitary subterranean rodent Ctenomys talarum. Specifically, we aimed to test individual differences in behavior that are stable over time and context in males of C. talarum captured in the wild. Methods Our experimental design included two series of three behavioral tests each, carried out with a 35 day time interval. Each series included an Open Field test, a Social Encounter test, and an Open Field test with a predator stimulus. Results Of the total recorded behaviors, 55.55% showed temporal consistency. Principal component analysis of consistent behaviors grouped them into four dimensions that explain inter individual behavioral variability, in order of importance: activity, socioaversion, boldness and exploration. Therefore, our results suggest that the concept of animal personality is applicable to C. talarum and the dimensions found are in accordance with the ecological and behavioral characteristics of this species.

Preferential use of one paw during feeding in the subterranean rodent Ctenomys talarum

This is a Short Note without an abstract.