| Abstract: | Progesterone levels and vaginal smears were monitored to detect estrus and formation of corpora lutea during the first year of a 4-year study of reproduction in captive wolverines. No evidence of spontaneous ovulation was detected during the first year, and most females did not attain complete vaginal cornification. Follicle stimulating hormone was used in subsequent years to induce estrus in several females, and human chorionic gonadotropin (hCG) was used to induce ovulation. Females treated with hCG were artificially inseminated with fresh wolverine semen. Prolonged elevation of serum progesterone above 1 ng/ml was only observed in females that received hCG. The profiles and duration of the progesterone secretory pattern of these females closely resembled that of other mustelids that exhibit a prolonged delay of implantation. Progesterone remained below 1 ng/ml throughout the year in all females that did not receive hCG. No kits were produced. The data suggest that ovulation in this species is normally induced by coitus, and that pseudopregnancy can occur, lasting as long as pregnancy. © 1993 Wiley-Liss, Inc. |
