Do male crows ever incubate?
I have never seen a male American Crow incubate, and I have not heard of any truly convincing cases of males incubating. My colleague Dr. Carolee Caffrey has spent hundreds of hours watching nests of marked crows in California, and she also has never seen anyone but the breeding female incubate. Female-only incubation is typical of the family Corvidae. Only females get brood patches, the defeathered, highly vascularized patches on the belly and chest that are in contact with the eggs. Any report of males incubating needs detailed verification. (See for example, Hailman & Woolfenden, 1985, Nest-defense of the Florida Scrub Jay and the problem of “incubation” by male passerines, Wilson Bulletin 97(3): 370-372.) The reports of shared incubation in popular reference sources (like Harrison’s bird nest book) appear to be repeated quotes from the same source: Bent’s life histories, quoting Bendire. I have read Bendire (1895, Life histories of North American birds) and he gives absolutely no d
