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
Heinroth's shearwater behaviour of close relatives). There is very little information about the species and it is uncertain if it is threatened or in decline. BirdLife International (2006) Species factsheet: Puffinus heinrothi. Downloaded from http://www.birdlife.org on 26/7/2006 Heinroth's shearwater Heinroth's shearwater ("Puffinus heinrothi") is a poorly known seabird in the family Procellariidae. Probably a close relative of the little shearwater or Audubon's shearwater (with which it is sometimes considered conspecific), it is distinguished by a long and slender bill and a brown-washed underside. This species is restricted to the seas around the Bismarck Archipelago and northern Solomon Islands. The breeding sites of