Periovulatory changes in behavior and fecal hormone metabolite concentrations but not vaginal cytology or vaginoscopy are indicative for the fertile period in female African wild dogs (Lycaon pictus)

Abstract

Artificial insemination (AI) can aid conservation of African wild dogs (AWD), but methods to determine the appropriate timing of AI in females are not feasible without immobilization. This study determined whether certain behaviors coupled with fecal estrogen (fEM) and progestogen (fPM) metabolite concentrations, could be used as non-invasive parameters to predict the fertile period in female AWDs. Behavior was observed in three alpha females before, during and after the mating period, and feces analyzed for hormone metabolites. During the periovulatory period, females were immobilized 2–3 times to evaluate vulvar condition, blood hormone concentrations and vaginal cytology, and to conduct vaginoscopy. Late estrus (fertile period) could be distinguished from pro-estrus, early estrus, and diestrus using behavior; with a 2- to 5-fold higher rate of male-female affiliative behavior, sexual and non-sexual follow, alpha male initiating behavior, ride-up and copulation (P ≤ 0.05). Sexual behaviors, and male-female resting patterns declined significantly or ceased the day after last mating. Two females showed a 2.5- to 3-fold increase in fPM concentrations during late estrus compared to the pro-estrus period (P ≤ 0.05) and elevated fEM levels that rose in pro-estrus, declined to baseline by late estrus. The one anovulatory female showed no distinct pattern in fPM or fEM concentrations. Vaginal cytology and vaginoscopy could not discriminate between different phases. In summary, behavioral observations coupled with rising fPM and declining fEM can determine the fertile period in African wild dog females, whereas infrequent measurement of blood hormone concentrations, vaginal cytology and vaginoscopy are unreliable.