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
Arripis commensal relationship between the Australian salmon and the birds is noted to be especially strong in such species as the white-fronted tern, ("Sterna striata"), fluttering shearwater, ("Puffinus gavia"), and Buller's shearwater, ("Puffinus bulleri"). The baitfish made available by the Australian salmon's herding behaviour may also be important to the reproductive success of winter-nesting birds; the decline of the Australians salmon stocks has evoked concern for these bird species, some of which – such as the fairy tern, ("Sterna nereis") – are endangered Aside from seabirds, the Australian salmon are also important in the diets of cetaceans, such as killer whales