A cuckoo that found the weather in Somerset unbearably cold has flown off to France.
David the cuckoo, one of five birds fitted with satellite tags, returned to the UK from the Democratic Republic of the Congo on Friday.
He got as far as Yeovil on his way to Ceredigion in Mid Wales, where he was tagged last year, but he then turned back across the English Channel.
He arrived in Bois in France, on Saturday and may be waiting for warmer weather, or planning to take a short break on the Continent.
“This is the first time we have observed this,” said Paul Stancliffe, a spokesman for the British Trust for Ornithology.
“We have suspected that birds turn to Europe if the UK is too cold, but we have never seen it.
“We have always wondered, if it is too cold or wet when they arrive, do birds lay low until it warms up, or do some birds head back across the channel and wait there?
“Now we know that some do return to Europe.”
The migration flight of cuckoos is determined by their food source, caterpillars which thrive in the climate of Cameroon
The cuckoo population declined by 27 per cent in Wales in the decade up to 2009 compared to 49 per cent in England and 9 per cent in Scotland.
“Cuckoo populations are declining rapidly in some parts of Britain: we want to find out why“, Dr Chris Hewson, who led the tagging project for the BTO told the BBC.
“Cuckoos only spend two months in the UK and 10 months elsewhere, so this is how we can find out what is happening to them.
“They are the sound of spring and the sound of the British countryside.
“They are a culturally resonant bird and people care about their conservation.
“Before the project we knew about reverse migration but only anecdotally,” he said.
“People would say they would hear cuckoos one day, then they would disappear ... now we know that this is true.”