PERIPARTURIENT BEHAVIOR OF SUCCESSFULLY REPRODUCING FARMED SILVER-FOX VIXENS

As part of a project series aiming at understanding the reproductive behaviour of farmed silver foxes, this paper describes the normal variation in behaviour around parturition shown by successfully reproducing vixens. The behaviour of 19 vixens (eight primiparous, 11 multiparous) kept under traditional management conditions, was video-recorded inside the breeding box day and night, and analyzed in four phases from 24 h before delivery to 72 h after. Births were distributed uniformly around the clock. True litter size at birth was 3.8 (SD=1.7) for primiparous vixens and 4.7 (SD=1.5) for multiparous vixens. The period elapsing between individual births was 56 (SD=29) min. The parturition period lasted 192 (SD= 87) min. The time-budget of behaviour showed a pronounced individual variation in all phases, but with few differences related to parity. During the last 24 h prior to parturition, the vixens stayed in the breeding box 63% of the time. Two-thirds of this time was spent resting or sleeping. All vixens dug vigorously on the box floor, on average for a total of 102 min, mainly during the last hours before parturition. Vixens never lined the nest with fur tangles. The delivery of cubs seemed to be quite easy, except for the first-born cub of some primiparous vixens. About 60% of the parturition phase was spent cleaning, grooming and inspecting cubs. During the 3 postparturient days, vixens rested or slept 70% of the time, though an average sleeping bout lasted only 11 min. Vixens showed active cub-care, mainly consisting of grooming cubs while lying down, for 24% of the time during the first postparturient day and for 18% during the next 2 days. This behaviour showed no relationship to litter size, indicating that an average cub receives more care the smaller the litter size. The vixens were rarely seen to retrieve cubs or to bring them outside the breeding box. Vixens left their boxes for an average total of 50 min per postparturient day. The results showed that not only multiparous, but also primiparous vixens may show completely adequate behaviour around parturition.