Personality-Associated Genetic Variation in Birds and Its Possible Significance for Avian Evolution, Conservation, and Welfare

Abstract

As free-living birds are relatively visible to human observers, bird behavioral studies have contributed greatly to ethology and behavioral ecology. Combining avian behavioral and molecular genetic studies might be expected to yield insights into both underlying neuroendocrine mechanisms and evolutionary processes associated with bird personalities. Associations between mammalian dopamine receptor D4 ( DRD4 ) gene polymorphisms and varying levels of novelty-seeking behavior have been reported. In a search for DRD4 polymorphism – novelty-seeking associations in a bird species (great tit, Parus major ) – a synonymous single nucleotide polymorphism (SNP) denoted SNP830 showed evidence of association with novelty-seeking behavior variation in both lines selected for divergent levels of early exploratory behavior (EEB) and unselected birds taken from a wild population. In addition, the phenotypic effect of SNP830 genotype may be influenced by a 15 bp indel polymorphism located 5′ to the DRD4 putative transcription initiation site. Remarkably, DRD4 genotype–behavior associations may predate the divergence of the avian and mammalian lineages. Identification of personality-associated genetic polymorphisms may assist the selective breeding of poultry for improved welfare, and preservation of personality-associated genetic diversity may prove important in avian conservation genetics.