THE RELATIONSHIP BETWEEN COMPETITION CAPACITY AND REPRODUCTION IN FARMED SILVER-FOX VIXENS, VULPES-VULPES

From the outset, poor reproduction in some of the vixens has been a problem in silver-fox farming. Some vixens fail to bear cubs and others kill their cubs just after delivery. To get a better understanding of reproductive behaviour in farmed silver fox vixens, their behaviour was compared with earlier observations made on groups of wild-living red foxes (Vulpes vulpes). The results indicated similarities in the reproductive behaviour of farmed silver foxes and group-living wild red foxes. Thus vixens that weaned most of their cubs unharmed, under standard farming conditions, had a higher competition capacity than vixens that did not wean cubs. Moreover, the vixens' competition capacity was a better reproductive indicator than age among related vixens (mother and her primiparous daughter). Furthermore, vixens that had previously been infanticidal, under standard farming conditions, weaned more cubs unharmed the next reproductive season, when isolated from the other vixens in the farm. The paper also describes a case description in which an infanticidal vixen adopted a cub from another vixen one hour after she had killed and eaten her own cub.