Reproductive biology of the black-footed ferret (Mustela nigripes)



Young, Kristen Mark

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University of Guelph


Reproductive cycles of the black-footed ferret were studied in captive colonies by fecal enzyme immunoassay. Estradiol, vaginal cornification and vulval area increased through proestrus, to reach maximal values during estrus and declined following intromission. Progesterone remained low until mating, increasing to day 10, plateaued and then declined to the day of expected parturition. Progesterone concentrations were significantly elevated in pregnant females beyond 14 days post-mating. Gestation length and litter size were 41.5 ± 0.5 days and 4.0 ± 0.3 kits, respectively. Animals $>$3 years and those experiencing more restraint episodes had poor reproductive success. A physical restraint/ACTH challenge consisting of four treatments was conducted on each ferret to evaluate adrenocortical function: cage restraint, saline, liquid ACTH, and gelatin ACTH. Only ACTH regimens significantly elevated fecal cortisol levels above pre-treatment baselines. Post-study basal cortisol values were significantly greater than pre-treatment counterparts, suggesting a stress effect caused by repeated restraint.



reproductive cycles, black-footed ferret, Mustela nigripes, captive colonies, fecal enzyme immunoassay