Reproductive steroid hormones and ovarian activity in felids of the Leopardus genus

Reproductive endocrine patterns were characterized in female ocelots (Leopa rdus pardalis; n = 3), tigrinas (Leopardus tigrinus; n = 2), and margays (L eopardus wiedii; n = 2) housed in captivity in southern Brazil. Females wer e maintained as singletons and exposed to natural fluctuations in photoperi od. Cyclic changes in ovarian steroids were monitored by analyzing estrogen and progestogen metabolites in fecal samples collected five times weekly f ar 14 to 18 months. Based on intervals between fecal estrogen peaks, mean ( +/- SEM) duration of the estrous cycle was 18.4 +/- 1.6 days for the ocelot s (range, 7-31 days; n = 75 cycles), 16.7 +/- 1.3 days for the tigrinas (ra nge, 11-27 days; n = 23 cycles), and 17.6 +/- 1.5 days for the margays (ran ge, 11-25 days; n = 32 cycles). Fecal progestogen analyses combined with tw o laparoscopic observations of the ovaries confirmed that ocelots and tigri nas did not ovulate spontaneously. In contrast, non-mating-induced luteal p hases of 40.1 +/- 6.3 days in duration (range, 30-60 days) were observed fr equently in both margays. There was no evidence of gonadal seasonality in m argays in either follicular or luteal activity. In ocelots, cyclic changes in estrogen excretion were observed during each month of the year; however, only one female cycled continuously. In the other two ocelots, periods of acyclicity of several months' duration were observed. It was not possible t o conclude whether tigrinas were aseasonal because estrous cyclicity was ob served in only one of two individuals. In the female that cycled, a 3-month period of acyclicity was observed in the late fall/early winter. These dat a demonstrate similarities among three felid species of the genus Leopardus , including evidence they are polyestrous but experience unexplained period s of ovarian inactivity. Only the margays differed by exhibiting occasional spontaneous, non-mating-induced ovulations. Historically, these species ha ve not bred well in captivity. However, it is hoped that understanding the biological similarities and differences among them could lead to improved m anagement strategies that may one day result in increased reproductive succ ess. (C) 2001 Wiley-Liss. Inc.