How do you help a migratory bird adapt to the climate crisis? One radical solution, as a team of Dutch ecologists discovered, is to move them further north.
Pied flycatchers are handsome black-and-white songbirds, which breed in deciduous woodlands across much of temperate Europe. Each autumn, they head south across the Sahara desert to overwinter in west Africa.
Like many long-distance migrants, flycatchers time their return journey north in spring by responding to gradual changes in light, rather than temperature. But because the climate crisis in Europe is shifting the timing of spring earlier and earlier, when they return to their breeding areas their food – mainly oak moth caterpillars – has already peaked.
So the scientists decided to trap some of the returning birds, and drive them almost 600km north, releasing them in suitable habitats in southern Sweden. Because spring comes two weeks’ later there than in the Netherlands, the hatching of the flycatchers’ chicks coincided perfectly with the peak of food supplies.
To the scientists’ delight, not only did these immigrant birds raise twice as many chicks as their Scandinavian counterparts but, the following spring, those birds returned to where they had been born, and bred successfully there.
Translocation is a drastic approach to help birds adapt to recent dramatic rises in global temperatures, but it worked, suggesting that conservationists should at least consider this as a future option.
