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
Saba (IBA AN006 "Saba Coastline") by BirdLife International. Saba is home to about sixty species of birds, many of which are sea birds that use the holes and crevices of the steep cliffs and two small islands for breeding and feed in the waters around the island. Saba’s shoreline is home to the Caribbean’s largest breeding colony of Red-billed tropicbird ("Phaethon aethereus"). The Audubon's Shearwater ("Puffinus lherminieri") is another common bird, and is the national bird of Saba as well as being featured on their coat of arms. Being an island, Saba is home to a number of endemic species including