Relationships between exploratory behaviour and genic heterozygosity in the oldfield mouse.

Exploratory behaviour by adult male oldfield mice (Peromyscus polionotus) from mainland and beach localities in the southeastern United States was examined in relation to mean genic heterozygosity. Heterozygosity was estimated from allelic variation in 31 proteins detectable by starch-gel electrophoresis. Mean latency to enter the open field decreased and mean ambulatory behaviour gel mainland samples of mice increased with increasing mean genic heterozygosity. Ambulatory behaviour was realted to the number of heterozygous loci per mouse in mainland mice as a group. The exploratory behaviour of beach mice diverged from relationships between behavioural performance and heterozygosity observed for mainland mice.