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
Ponta dos Rosais and agricultural areas, with most of the region taken-up by rural activities. Tourists visiting the area are attracted by the diversity of migratory and maritime bird species that nest in the cliffs of the point, including the migratory Corey's Shearwater ("Calonectris diomedea") and Little shearwater ("Puffinus assimilis"), but also the Roseate ("Sterna dougallii") and Common Terns ("Sterna hirundo"). Endemic predator species in these areas include feral cats and dogs, as well as rodents, but the latter limited by local kite species. But, the region is a hothouse of Azorean heather ("Erica azorica") and Forget-me-nots ("Myosotis azorica"). Ponta dos Rosais Ponta