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COOPERATIVE BREEDING OF THE NORTHWESTERN CROW CORVUS CAURINUS IN BRITISH COLUMBIA
Author(s) -
Verbeek Nicolaas A. M.,
Butler Robert W.
Publication year - 1981
Publication title -
ibis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 80
eISSN - 1474-919X
pISSN - 0019-1019
DOI - 10.1111/j.1474-919x.1981.tb00923.x
Subject(s) - nest (protein structural motif) , breeding pair , cooperative breeding , ecology , geography , nest box , biology , zoology , demography , predation , population , biochemistry , sociology
Summary The behaviour of helpers at nests of Northwestern Crows was studied on Mandarte Island and Mitlenatch Island, British Columbia. Not all nests had a helper and there was only one helper per nest. Helpers participated in varying degrees in the defence of the territory and nest, feeding of the nestlings and fledglings and they cached food on the territory. Adult males fed helpers, and helpers obtained most of their food on the adults' territory. Adults with helpers laid larger clutches and produced more fledglings per nest than adults without helpers. It is suggested that cooperative breeding in the Northwestern Crow is of recent origin.