Effects of early experience on subsequent parental behaviour and reproductive success in oldfield mice, Peromyscus polionotus

Studies of a variety of taxa have almost universally shown an increase in survivorship between the first cohort of young reared by a female (or both parents) and subsequent litters. Here, we examine the effect of early experience with sibling pups during the subadult period on later maternal behaviour and reproductive success in oldfield mice. 'Experienced' females remained with their mothers through the rearing of a litter of siblings. 'Inexperienced' females were removed from their parents at 20 days of age and had no prior exposure to pups before they reproduced. Twenty-four experienced females and 24 inexperienced females (each a full sibling of an experienced female) were paired with noninbred, inexperienced males through the birth and rearing of three litters. Litter survival improved significantly with experience and increasing parity. Pairs with experienced females showed improved nest-building behaviour and averaged significantly more surviving pups than did pairs with inexperienced females. Inexperienced mates of experienced females showed improved nest building, as well, consistent with the results of previous studies showing that paternal care tends to match that of mates. Maternal body weight did not appear to influence reproductive performance. These findings support the contention that individuals may accrue significant fitness benefits by delaying their own reproduction and gaining experience. (c) 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.