Hungry birds as climate change drives food 'mismatch'

April 23, 2018, University of Exeter
Female Pied flycatcher. Credit: Tom Wallis

Warmer springs create a "mismatch" where hungry chicks hatch too late to feast on abundant caterpillars, new research shows.

With continued spring warming expected due to climate change, scientists say hatching of forest birds will be "increasingly mismatched" with peaks in caterpillar numbers.

The researchers, from the RSPB and the universities of Exeter and Edinburgh, used data collected across the UK—largely by citizen scientists—to study spring emergence of oak tree leaves and caterpillars, and timing of nesting by three bird species: , and pied flycatchers.

They also tested a theory that some bird species in southern Britain may suffer most due to a greater mismatch effect—but they found no evidence of this.

"Forests have a short peak in caterpillar abundance, and some time their breeding so this coincides with the time when their chicks are hungriest," said Dr. Malcolm Burgess, of the University of Exeter and the RSPB.

"With spring coming earlier due to climate change, leaves and emerge earlier and birds need to breed earlier to avoid being mismatched.

"We found that the earlier the spring, the less able birds are to do this.

Female Pied flycatcher. Credit: Tom Wallis
"The biggest mismatch was among pied flycatchers—as migratory birds, they are not in the UK in winter and therefore are much less able to respond to earlier weather."

The study presents the first assessment of whether the mismatch effect is greater in southern Britain than the north.

It has been suggested that northern bird populations may be "buffered" from the effects of in this way.

Dr. Ally Phillimore, from the University of Edinburgh, said: "We found no evidence of north-south variation in caterpillar-bird mismatch for any of the . Therefore, population declines of insectivorous birds in southern Britain do not appear to be caused by greater mismatch in the south than the north."

Dr. Karl Evans, from the University of Sheffield's Department of Animal and Plant Sciences, said "Our work suggests that as springs warm in the future less food is likely to be available for the chicks of insectivorous woodland unless evolution changes their timing of breeding."

Female Pied flycatcher. Credit: Tom Wallis

First leafing dates of oak trees were collected by citizen scientists coordinated by the Woodland Trust via Nature's Calendar, caterpillar abundance was monitored by collecting frass (droppings) beneath oak trees, and the timing of egg laying by blue tits, great tits and pied flycatchers were recorded by the British Trust for Ornithology's long-running Nest Record Scheme.

The research team also included the universities of Durham, Glasgow, Oxford, Stirling and Cardiff.

The paper, published in the journal Nature Ecology and Evolution, is entitled: "Tritrophic phenological match-mismatch in space and time."

Explore further: Birds time breeding to hit 'peak caterpillar'

More information: Tritrophic phenological match–mismatch in space and time, Nature Ecology and Evolution (2018).

Related Stories

Birds time breeding to hit 'peak caterpillar'

May 25, 2015

When oaks burst into life in spring populations of oak-leaf-eating caterpillars boom: this offers a food bonanza for caterpillar-munching birds looking to raise a family.

Timing of spring birdsong provides climate insights

January 17, 2018

Climate change has scientists worried that birds' annual migration and reproduction will be thrown out of sync with the seasons. Because birds' songs are correlated with their breeding behavior and are easily identifiable ...

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.