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
Muttonbirding on 36 islands, known as the Titi or Muttonbird Islands, around Rakiura (Stewart Island), is managed entirely by Rakiura Māori. There is some evidence that this harvest has been occurring since at least the 17th century. Muttonbird may refer to various seabirds, particularly petrels in the genus "Puffinus", called shearwaters, where the young birds are harvested for food and oil by being extracted by hand from the nesting burrows before they fledge. Some species are: Muttonbirding Muttonbirding is the seasonal harvesting of the chicks of petrels, especially shearwater species, for food, oil and feathers by recreational or commercial hunters. Such