Genetic and behavioural analysis in three typical colonies of Jackdaws (Corvus monedula)

Abstract

Breeding density colonies structure of Jackdaw (Corvus monedula) depends on the existence of appropriate cavities. In this work we report the social behavioural and genetic characteristics of Jackdaw colonies located in three typical hosting structures. To assess genetic structure a microsatellite analysis was performed throughout four polymorphic loci. During field activity a strong hierarchy in “natural cliff” and “modern bridge” colonies was revealed, compared to “mediaeval bell tower” colony. The colony located on the modern bridge showed the lower value of genetic variability. A high variability level was shown in the natural cliff, allowing the bird nesting in casually distributed cavities on a bi-dimensional surface, and in the tower that offers the chance of nesting on four sides of a three-dimensional volume. Hardy-Weinberg equilibrium in the three colonies was discussed considering social structure of the birds.