Increased survival and reproductive success associated with stereotypical behaviours in laboratory-bred bank voles (Clethrionomys glareolus)

The aim of this study was to examine whether voles performing stereotypic behaviours (Ster) differed in physical welfare from voles, which did not develop stereotypies (N-Ster). The chosen variables were reproductive success and capacity to survive barren housing conditions. Furthermore, effect of weight on proneness to develop stereotypic behaviours were examined. Singly housed Ster (n = 62) in barren cages showed superior survival when compared to similar housed N-Ster (n = 38; p = 0.002). Furthermore, Ster females (n = 25) gave birth to both a first and second litter faster than N-Ster females (n = 14; p <= 0.019). Litter size, number of weanlings and proportion of barren females did not differ between Ster and N-Ster, but pups from Ster experienced a higher pre-weaning mortality in the second litter (p = 0.0095). Voles classed as Ster within age 6 month (n = 55) weighed less than same aged N-Ster (n = 45) already from weaning (21 days; p = 0.0204). However, weight at weaning, whether LIGHT (weight <= median; n = 47) or HEAVY (weight > median; n = 53), had no effect on subsequent development of stereotypies in terms of either onset age or fraction which developed stereotypies. The results suggested that Ster had better physical welfare, as reflected in better survival, than N-Ster when housed singly and a higher reproductive success when used as breeders. (C) 2009 Elsevier B.V. All rights reserved.