乌鸦学会打开巢箱进行捕食

本文首次报道了大嘴乌鸦（Corvus macrorhynchos）学会打开人工巢箱捕食在里面繁殖的绿背山雀（Parus monticolus），包括成鸟、雏鸟和卵。这种行为极有可能是通过观察人类行为而习得，但需要进一步研究来验证。

Crows Learn to Open Nest-boxes for Predation

Here we reported that the Large-billed Crow (Corvus macrorhynchos) could open the next-boxes and predate the eggs, nestlings or adults of Green-backed Tit (Parus monticolus). Totally 43 nest-boxes were found to be opened, of which 4 were recorded by cameras, 2 were witnessed by observers of being opened by the crows, and 20 were found crow activities nearby. We assumed that all the nest-boxes were opened by crows, as no human activities or other Corvids were found around the nest-boxes. Of these 43 nest-boxes been opened, 19 were at incubating and nestling period of the Green-backed Tit, and 5 nest-boxes of adults, 3 nest-boxes of adults and eggs, 1 nest-boxes of adults and nestlings, 2 nest-boxes of nestlings and 8 nest-boxes of eggs were predated. For the cases that adults were predated, their blood and residual plumages could be detected. We suspect that crows might be able to open the nest-boxes by observing and learning from human practices, which would be confirmed by further studies.