The Western Eurasian Jackdaw, Coloeus monedula spermologus, is a passerine bird in the Crow family and measures between 34 and 39 centimetres (13–15 in) in length. It is found across Europe, western Asia and North Africa and, despite not being a particularly common sight in many areas, there are estimated to be between 15.6 and 45 million individuals just in Europe alone.

Description

Most of the plumage is a shiny black, with a purple (in subspecies monedula and spermologus) or blue (in subspecies cirtensis and soemmerringii) sheen on the crown, forehead, and secondaries, and a greeny-bluey sheen on the throat, primaries, and tail. The cheeks, nape and neck are light grey to greyish-silver, and the underparts are slate-grey. The legs are black, as is the bill. The irises of adults are greyish or silvery white while those of juveniles are light blue, becoming brownish before whitening at around one year of age.

This sub-species is easily distinguishable by the lack of a whitish border at the base of the grey nape.

Breeding

Western jackdaws usually breed in colonies with pairs collaborating to find a nest site, which they then vigorously defend from all comers for most of the year. They nest in cavities in trees or cliffs, in ruined or occupied buildings and in chimneys as they favour a sheltered site for the nest.

Nests are lined with hair, wool, dead grass and many other materials. The eggs are a glossy pale blue or blue-green with darker speckles ranging from dark brown to olive or grey-violet. The young usually fledge within 4 to 5 weeks.

Diet

Jackdaws are omnivorous and great foragers.