Tardy birds fail to catch caterpillars

Warmer springs are creating a “mismatch” whereby hungry chicks hatch too late to feast on abundant caterpillars, new research has shown.

With climate change expected to deliver warmer spring temperatures, scientists say the difference in timing between the hatching of birds and peaks in caterpillar numbers is likely to continue to worsen.

Researchers from the RSPB and the universities of Exeter and Edinburgh studied the emergence of oak tree leaves and caterpillars, and the timing of nesting by three bird species: blue tits, great tits and pied flycatchers.

The biggest mismatch was among pied flycatchers and their caterpillar supply. Migratory flycatchers, that are not in the UK in winter, are less able to respond to earlier spring weather. It had been suggested that northern birds would be less affected, but researchers found no evidence of this. Samantha Herbert