Western jackdaw amounts of silicaceous and calcareous grit to aid digestion of vegetable food and supply dietary calcium. Opportunistic and highly adaptable, the western jackdaw varies its diet markedly depending on available food sources. They have been recorded taking eggs and nestlings from the nests of the skylark ("Alauda arvensis"), Manx shearwater ("Puffinus puffinus"), razorbill ("Alca torda"), common murre ("Uria aalge"), grey heron ("Ardea cinerea"), rock pigeon ("Columba livia"), and Eurasian collared dove ("Streptopelia decaocto"). A field study of a large city dump on the outskirts of León in northwestern Spain showed that western jackdaws forage there in the early morning and
Flesh-footed shearwater Flesh-footed shearwater The flesh-footed shearwater ("Ardenna carneipes"; formerly "Puffinus carneipes") is a medium-sized shearwater. Its plumage is black. It has pale pinkish feet, and a pale bill with a distinct black tip. Together with the equally light-billed pink-footed shearwater, it forms the "Hemipuffinus" group, a superspecies which may or may not have an Atlantic relative in the great shearwater. These are large shearwaters which are among those that have been separated in the genus "Ardenna". It breeds in colonies, and has two main breeding areas: one in the southwest Pacific Ocean includes Lord Howe Island (16,900 pairs ), South Australia