Garden birds starve as climate change makes spring early
GARDEN birds such as blue and great tits face starvation due to climate change, experts warned yesterday.
Warmer, earlier springs are creating a “mismatch” where chicks hatch too late for the seasonal glut of caterpillars on which they rely for food.
The worst affected bird is the pied flycatcher which cannot easily adapt to Britain’s changing climate because it migrates here from Africa.
Dr Karl Evans, at University of Sheffield’s animal and plant sciences department, said: “Our work suggests as springs warm in the future less food is likely to be available for chicks of insectivorous woodland birds unless evolution changes their timing of breeding.”
Conservationists have long warned that climate change could affect the rearing of chicks by getting nesting out of sync with the seasons.
Mismatched
Dr Malcolm Burgess of the Royal Society for the Protection of Birds said: “Forests have a short peak in caterpillar abundance and some forest birds time their breeding to coincide with the time when their chicks are hungriest.
“With spring coming earlier due to climate change, leaves and caterpillars emerge earlier and birds need to breed earlier to avoid being mismatched.
“We found the earlier the spring, the less able birds are to do this. The biggest mismatch was among pied flycatchers. As migratory birds, they’re not in the UK in winter and so less able to respond to earlier spring weather.”
Researchers at the RSPB and the Universities of Exeter and Edinburgh analysed when chicks of blue and great tits and pied flycatchers hatched based on records from the British Trust for Ornithology.
They then compared these to records of the first leafing of oak trees from the Woodland Trust’s Nature’s Calendar as well as caterpillars numbers, reports the journal Nature Ecology & Evolution.
Scientists found climate warming did not appear to create a greater mismatch among birds in the South than the North. The study analysed data from 1965 to 2016.