title: Reproductive cycle of the steppe polecat (Mustela eversmanni).
abstract: In laboratory conditions, in a natural photoperiod, testicular redevelopment began in late December. Maximal testis size was attained by the end of February. Testicular regression began in mid-May and was complete by the end of August. Oestrus was first observed in late March and continued throughout April. Females mated for the first time between 30 March and 8 April. Mating generally coincided with peak concentrations of urinary oestrone conjugates and when vaginal lavages contained greater than 90% cornified epithelial cells. Blastocyst implantation occurred by Day 13 and the post-implantation period was 29 days. Gestation ranged from 39 to 43 days and first parturition occurred in mid-May. Concentrations of urinary oestrone conjugates and free progesterone were elevated during the first half of pregnancy, reaching maximum values at mid-pregnancy, and then gradually declined as parturition neared. Litter size of primiparous females averaged 6.8 young/female. Females that were pseudopregnant or lost their litters shortly after birth, and several with weaned kits, exhibited a second oestrus.
authors.affiliation: Department of Biological Sciences, University of Idaho, Moscow 83843.
authors.forename: R A
authors.initials: RA
authors.lastname: Mead
authors.forename: S
authors.initials: S
authors.lastname: Neirinckx
authors.forename: N M
authors.initials: NM
authors.lastname: Czekala
mesh_terms: D000818:Animals; D002335:Carnivora / Q000502:physiology*; D004966:Estrogens, Conjugated (USP) / Q000652:urine; D004971:Estrus / Q000502:physiology; D005260:Female; D005289:Ferrets / Q000502:physiology*; D008098:Litter Size; D008297:Male; D011247:Pregnancy; D011374:Progesterone / Q000652:urine; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D013737:Testis / Q000033:anatomy & histology / Q000502:physiology
chemical_list: D004966:Estrogens, Conjugated (USP); D011374:Progesterone