Hormonal and Behavioral Responses to Odor Cues in Zoo-Housed African Painted Dogs (Lycaon pictus)

Abstract

Environmental enrichment can improve the welfare of animals in zoos by eliciting natural behavior and physiological responses. We measured activity and stress physiology in four 3-year-old female African painted dogs (APD; Lycaon pictus) at Lincoln Park Zoo when they were presented with odors from lion, Grant’s gazelle, and cattle feces, to determine if these odors provide environmental enrichment. Each odor was presented for 3 days at 2-week intervals. Behavior was recorded using instantaneous scan-sampling with a 1‐min fixed interval and all-occurrence methods. Feces were collected daily during the odor cue presentations and twice weekly in the time periods before and after the cues. Fecal glucocorticoid metabolite concentrations (FGMs) were measured using a corticosterone enzyme immunoassay. Data were analyzed by social rank (APD-1 and APD-2 are dominant; APD-3 and APD-4 are subordinate), individual, and time period pre-, during- and post-cue. Overall, all the females were more active (P = 0.023) when odors were present than when they were not. When odors were present, APD-4 was the most active (P < 0.001), followed by APD-1 who was more active (P < 0.001) than APD-2 and APD-3. The females were more active (P = 0.032) in response to lion than to cattle odor. In ascending order of overall mean FGMs, the females ranked APD-4, APD-2, APD-1, and APD-3 which did not reflect social rank. None of the odors made a consistent difference to FGMs, but all odors provided environmental enrichment that increased activity.