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
Flinders Island provided by many small streams, few of them permanently flowing directly leading to the waters of Bass Strait or such a lagoon. The coastal areas are mainly covered in scrub or shrubs, whereas the vegetation at a higher elevation consists of woodland, mainly eucalyptus species. The total number of plant species in the Furneaux Group well exceeds 800, showing the great biodiversity of its ecosystem. Native bird species include the Cape Barren goose ("Cereopsis novaehollandiae") and the short-tailed shearwater ("Puffinus tenuirostris"). Marsupial mammals are represented by Bennett's wallaby ("Macropus rufogriseus"), brushtail possum ("Trichosurus vulpecula"), eastern pygmy possum ("Cercartetus nanus"), potoroo