Reproduction of Blue foxes (Alopex lagopus) with Different Number of Chromosomes

Abstract

The karyotypes 2n=48, 49 and 50 were in the breeding stock of Alopex species on a Danish fur farm represented in proportions 14-45-41%. Reproduction data is presented for 450 females of which 296 were mated with Alopex males and 154 used in interspecific crossing with Vulpes males. In Alopex×Alopex matings the age of the female had a significant effect on litter size. First year females averaged 1.3 pups less per litter than proven females. No effect of karyotype could be seen among young females. Among old females the karyotype 2n=49 reduced litter size with 0.7 pups per litter compared to karyotype 2n=50. In crossing with Vulpes males no consequent effect of age or karyotype was observed.