They warn that a resulting “ecological mismatch” could be the main reason the birds’ populations are declining.
Long-distance migratory species are the most impacted, according to Nicola Saino of the University of Milan.
His study of the spring arrival of 117 species over the past 50 years indicates that the birds are now missing the best period in which to breed.
Spring is arriving an average of 11 days earlier than it did 30 years ago across much of Europe.
“Peaks in food abundance, such as insects, are very narrow in northern latitudes; so if you arrive too late and miss the peak, then you miss the best opportunity to raise your offspring,” Saino writes.