Periparturient behaviour in farmed blue foxes ( Alopex lagopus)

Abstract

Recently, there has been criticism of the housing conditions available for farmed foxes. It is claimed that the present farm conditions are not appropriate for foxes and they lead to poor reproduction and abnormal behaviour such as maternal infanticide. Earlier studies have indicated that farmed silver foxes can be infanticidal. The main factors leading to infanticidal behaviour seem to be of a social nature rather than factors related to the physical housing environment. However, this infanticidal behaviour of silver foxes has often been extrapolated to the farmed blue fox although previous studies have indicated that the situation in farmed blue foxes seems to be quite different. Our study aimed at describing and quantifying periparturient behaviour in blue fox vixens inside their nest box, with special emphasis on possible infanticidal behaviour. The behaviour of 16 vixens was video-recorded from 7 days before the expected delivery to 7 days postpartum. The behaviour was analysed separately for pre-, peri- and postpartum periods. Moreover, reproductive performance and cub mortality from birth to weaning were evaluated. The mean litter size at birth was 10.8 cubs, but this had declined to 7.8 cubs at weaning ( P < 0.05, GLM). Approximately 2% of the cubs were stillborn and 80% of the cub deaths occurred during the first week of life. The postnatal cub mortality was higher among the primiparous than in the multiparous vixens (32.7 and 16.7% of cubs, respectively, P < 0.05, χ 2-test), animals which had already undergone selection for their good reproductive capabilities. Despite the neonatal cub losses, the blue fox vixens exhibited proper maternal care. During parturition, the vixens licked their genital area and helped actively in the deliveries whenever necessary. Between the deliveries of individual cubs and after parturition, the vixens showed sufficient cub-care and nursing behaviour. Most importantly, no obvious signs of maternal infanticide were observed. There were no major differences in the periparturient behaviour of the young and old females, although the primiparous vixens were probably more restless than their multiparous counterparts. Our results confirm that the lack of maternal behaviour in farmed blue foxes is not a common problem. In the present study, behavioural problems such as infanticide were not observed. However, the cub losses were still relatively high. Accordingly, management in blue fox production needs evaluation and improvement to enhance cub survival. Therefore, we wish to emphasize the behavioural differences and farming practices between farmed blue and silver foxes. Moreover, we suggest that one should be cautious of extrapolating results from one species to another, even when those species are closely related.