Coloeus

Coloeus is a small genus of passerine birds in the crow family (Corvidae) that, in many classifications, includes the Eurasian jackdaw (Coloeus monedula) and the Daurian jackdaw (Coloeus dauuricus). Some authorities treat Coloeus as a subgenus within the broader genus Corvus, leading to taxonomic dispute. The distinction is based on morphological, vocal, and behavioral differences observed between populations.

These birds are medium-sized crows with glossy black plumage. The Eurasian jackdaw typically shows a pale gray nape and upper breast and has pale eyes, while the Daurian jackdaw is often more uniformly dark with subtle regional differences. Juveniles of both species are generally brownish with streaked underparts and acquire adult plumage over time. Both share a compact build, strong bill, and agile behavior typical of corvids.

Coloeus jackdaws are widespread across Europe and Asia, occupying a range of habitats from woodlands and farmland to towns and cities. They are highly social, forming large flocks outside the breeding season and displaying complex vocalizations and cooperative behaviors. Their diet is omnivorous, including invertebrates, seeds, grains, fruits, eggs, and human refuse.

Breeding takes place in cavities, such as tree holes, cliffs, or buildings. Both parents participate in nest building, incubation, and raising the young. Clutch size typically ranges from four to six eggs, and gregarious juveniles may disperse with flocks after leaving the nest.

Overall, Coloeus jackdaws are common and adaptable members of the corvid community, with ongoing taxonomic debates reflecting broader discussions about genus-level separations within Corvidae.