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
Bannerman's shearwater to feed on fish, squid and cephalopods, by surface-seizing, underwater pursuit, including diving and plunging, and pattering (del Hoyo et al. 1992, Brooke 2004). It is likely to nest in rock crevices or burrows and form colonies (del Hoyo et al. 1992). Bannerman's shearwater Bannerman's shearwater ("Puffinus bannermani") is a seabird in the Procellariidae family formerly considered conspecific with Audubon's shearwater ("Puffinus lherminieri"). Little is known of this species other than that it breeds in the Volcano Islands in the Ogasawara Group to the southwest of Japan and doesn't seem to range far from this area. The species population size