On one of our visit of the quarry we observed an interesting phenomenon – interspecific feeding in birds. During our previous visits we found nests of nuthatches (Sitta europaea) and great spotted woodpeckers (Dendrocopos major) situated on the same tree, just one meter apart of each other. While nuthatches were already taking care of their nestlings, woodpeckers only incubated eggs. On our next visit we noticed that both woodpeckers and nuthatches come to the same cavity and both feed woodpeckers’ nestlings.
This phenomenon when individuals of one species feed offspring of another species is call interspecific feeding. It is sometimes found among birds, yet the origin of this behaviour is not well known and probably has no evolutionary impact. Shy in his review from 1982 mentioned several occurrences of interspecific feeding and proposed eight categories. Our case probably falls into the category “Close nesting of another species”. Nest cavity of nuthatches was close to the woodpeckers’ cavity and woodpecker nestlings are very loud, which could stimulate nuthatches into taking care of them even after they fledge their own offspring. This shows that even in a habitat such as a quarry and small forest fragment can be observed such interesting patterns in animal behaviour.
Shy M. M. (1982) Interspecific feeding among birds: A review. Journal of Field Ornithology 53: 370-393.