Why do migratory birds often have lighter feathers than usual?

Migratory birds make their own adjustments, especially over extreme long distances.

Recently, a study published in the journal Current Biology has discovered an unexpected way to help migratory birds maintain their composure and endurance during arduous journeys. The coat color is lighter and brighter.

Migratory plumage color is lighter to reduce the risk of overheating when exposed to the sun.

"We found that most migratory birds tend to have lighter and brighter feathers than non-migratory species," said expert Kaspar Delhey of the Max Planck Institute Seewiesen, Germany. We think that the lighter coat color chosen is found in migratory species, as it reduces the risk of overheating from exposure to the sun during a long, harsh migration' , added Kaspar Delhey.

Because in principle, lighter, lighter colored surfaces will help absorb less heat than dark ones, which is easy to see in practice as anyone who wears dark clothing on a sunny day can attest. This will also be especially important for long-distance migratory birds.

Lighter colored birds are often found in areas with high temperatures and little shade.

Delhey and colleagues studied the effect of climate on bird color. Previous studies have also shown that, in general, lighter-colored birds are found in areas with high temperatures and little shade. Perhaps that's partly because the birds' lighter, lighter plumage helps keep them cooler when exposed to frequent hot weather.

The finding is another reminder of the important role temperature and climate factors play in shaping the evolution of animal coloration.

They also have clear implications for understanding the impact of global warming on potential adaptive evolutionary responses in the animal kingdom, the researchers say.