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 pr oblem 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 wa s compared with earlier observations made on groups of wild-living red foxes (Vulpes vulpes). The results indicated similarities in the repr oductive behaviour of farmed silver foxes and group-living wild red fo xes. Thus vixens that weaned most of their cubs unharmed, under standa rd farming conditions, had a higher competition capacity than vixens t hat 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 cub s unharmed the next reproductive season, when isolated from the other vixens in the farm. The paper also describes a case description in whi ch an infanticidal vixen adopted a cub from another vixen one hour aft er she had killed and eaten her own cub.