Opportunistic birds shift victims in response to earlier springs
Warming temperatures in parts of Europe may be knocking the local cuckoos out of sync with some of their usual targets for illicit egg laying.
Cuckoos swoop in to the nests of other bird species and lay eggs. After hatching, a cuckoo chick kills its foster siblings and hogs the food for itself. In parts of Europe that have warmed since 1990, the common cuckoo, Cuculus canorus, appears to be shifting its targets away from bird species that either don’t migrate or that travel only a relatively short distance each year, says Anders Pape Møller, a researcher for the French nation