Free female mate choice in house mice affects reproductive success and offspring viability and performance

We tested a critical assumption of sexual dialectics theory (Gowaty 1997, Feminism and Evolutionary Biology, Chapman & Hall) using house mice, Mus musculus. We asked if female house mice accrue viability benefits for their offspring when they mate with males they prefer versus with males they do not prefer. Our experiment was designed to eliminate or control other mechanisms of reproductive competition besides female mate choice. After allowing females to discriminate behaviourally between two males, which were at random with respect to phenotypic variation discriminating females were paired with preferred (P) or nonpreferred (NP) males. We then tested whether females mating with males they preferred had offspring of higher viability than females mating with nonpreferred males. In pairwise comparisons, we tested for differences in offspring performance in dominance contests and in nest-building skill. At weaning, we exposed half of the pups to cold stress. We tested progeny performance and viability in the laboratory or in outdoor field enclosures. In:comparison to P females, NP females produced significantly fewer litters. Sons from P matings were socially dominant to sons from NP matings. Adult offspring from P matings;built better nests than those from NP matings. In field enclosures significantly fewer NP than P offspring survived to 60 days after introduction. Male and female progeny from P matings established larger home ranges and constructed better nests than progeny from NP matings. This is the first demonstration of progeny viability differences for females allowed to express mate preferences between males presented to them at random. (C) 2000 The Association for the Study of Animal Behaviour.