A reproductive analysis of a captive group of jaguars (Panthera onca) (n = 6) at the Santacruz Zoological Foundation in Cundinamarca, Colombia, was conducted by performing a longitudinal, noninvasive, hormonal analysis of estradiol and progestogens in females and of androgens in males. During four seasons, female jaguars confined in solitary were evaluated for ovarian activity and spontaneous ovulation, male jaguars for testicular activity. A second hormonal follow-up was conducted in the females after administration of gonadotropins. Hormones were extracted from fecal samples of three females (n = 3) and two males (n = 2). Estradiol measurements were obtained by radioimmunoassay (RIA) and progestogens by enzyme immunoassay (EIA). The linear mixed-effect regression (LMER) showed that there was a significant effect of seasons in the concentrations of estradiol (Chi square = 15.97, DF = 3, p < 0.01). Post hoc comparisons of all pairs of seasonal means were conducted according to Tukey's honest significant difference (HSD), revealing significant differences between seasons: Dry 1 vs. Rains 2 (p < 0.01), Rains 1 vs. Rains 2 (p < 0.05), and Dry 2 vs. Rains 2 (p < 0.05). Elevations of progestogens compatible with spontaneous ovulation occurred in three jaguars and the LMER showed that there was also a significant effect of seasons (Chi square = 28.56, DF = 3, p < 0.01). Post hoc comparisons showed significant differences only between seasons: Dry 2 vs. Rains 2 (p < 0.01). The season with the lowest average concentration was Rains 2 (October, November, and December). During this season, periods of anestrous were registered that lasted between 31 and 83 days. The three females presented estradiol peaks after the administration of eCG. A noninvasive longitudinal analysis for androgens was also made (Males 1 and 2) over the course of one year, and no significant differences were found between the different seasons. A seminal analysis of three adult male jaguars (Panthera onca) (n = 3) was also performed after electro-ejaculation under general anesthesia (Male 1 and 2) and by a postmortem epididymal wash (Male 3). The mean concentration of spermatozoids was 5.7 x 106 ± 1.1 x 106 spermatozoa/ml. The progressive motility SD averaged 80 %. The percentage of normal spermatozoids obtained by electro-ejaculation was 80 ± 2.8%, and the abnormalities found more frequently were head defects (7 ± 1.4%). The seminal fluid obtained by epididymal flush contained 35 ± 1.4% normal spermatozoids, and the most frequent abnormalities found corresponded to distal cytoplasmic droplets (39 ± 11.3%).
