Researchers have found yet another way in which climate change has been detrimental to migrating birds. As European winters have become warmer, pied flycatchers traveling from Africa over long distances to reach breeding grounds in the Netherlands are arriving to find that resident great tits have already claimed nesting sites for the season. As a result, the number of flycatchers killed in great tit nests has risen dramatically. The work appears January 10 in the journal Current Biology.