Interspecific feeding refers to behaviour reported in wild animals, particularly birds where adults of one species feed the young of another species. This usually excludes the case of birds feeding brood parasites. The behaviour has been of theoretical interest since it appears to be provide little evolutionary benefit to the feeding bird.[1][2][3][4] Some researchers have suggested that it is mainly male birds that are lured into feeding a fledgling that begs.[5][6][7][8]
Male bird feeding another species while mate incubated
Feeding bird is mateless and finds a mateless bird at nest
Shy (1982) listed 65 species of birds involved in interspecific feeding. Riedman (1982) listed 150 species of birds that adopted young that did not belong to themselves.[10]
^Riedman, Marianne L. (1982). "The Evolution of Alloparental Care and Adoption in Mammals and Birds". The Quarterly Review of Biology. 57 (4): 405–435. doi:10.1086/412936. JSTOR2826887. S2CID85378202.