The behavioral response of the crab-eating fox to olfactory enrichment

Abstract

The effect of olfactory stimuli as a means of environmental enrichment is underexplored in canids. The crab-eating fox is the most abundant wild canid in zoos, but few studies have addressed the reaction of this species to olfactory cues. This study sought to investigate the reaction to olfactory stimuli in crab-eating fox with the aim of increasing their well-being. Four potentially attractive olfactory stimuli (meat, cheese, rat urine, and egg) were presented outside the enclosures in five-minute sessions. The reactions of the crab-eating foxes were filmed and analyzed using the focal animal method. All behaviors were recorded pre (Basal), during (Exp), and post (Pos) stimulus. Behavioral responses were classified as positive (P +), negative (N-), and other (Ot). The average times recorded for each category of behavior in each phase were analyzed. Olfactory stimuli significantly increased P + responses by up to 18.2 times (p < 0.001) during Exp, concomitant with a 2.3-fold increase in N- responses (p < 0.03). The category of Ot behaviors declined from the Basal (p < 001) for the Exp and remained low in the Pos (p < 001) in relation to the Basal. Only the category of P + behaviors remained increased (p < 0.001) in relation to the Basal, while the category of N- behaviors returned to baseline values (p > 0.05) after the withdrawal of the stimulus. Olfactory enrichment, as investigated in other species of mammals, was effective and led to a sustained increase in well-being, but the exposure time must be balanced so as not to elicit negative behaviors. The method used is innovative, low cost, and flexible. This is the first published study of olfactory enrichment for crab-eating foxes.