EVIDENCE FOR PSEUDOPREGNANCY AND INDUCED OVULATION IN CAPTIVE WOLVERINES (GULO-GULO)

Progesterone levels and vaginal smears were monitored to detect estrus and formation of corpora lutea during the first year of a 4-year stud y of reproduction in captive wolverines. No evidence of spontaneous ov ulation was detected during the first year, and most females did not a ttain complete vaginal cornification. Follicle stimulating hormone was used in subsequent years to induce estrus in several females, and hum an chorionic gonadotropin (hCG) was used to induce ovulation. Females treated with hCG were artificially inseminated with fresh wolverine se men. Prolonged elevation of serum progesterone above 1 ng/ml was only observed in females that received hCG. The profiles and duration of th e progesterone secretory pattern of these females closely resembled th at 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 tha t ovulation in this species is normally induced by coitus, and that ps eudopregnancy can occur, lasting as long as pregnancy. (C) 1993 Wiley- Liss, Inc.