Feather Weather

Flying off to a beach vacation? Pack sunscreen, bathing suits, and…feathers?!  

This is Sandra Tsing Loh with the Loh Down on Science.

Birds also migrate thousands of miles to warmer climates! But while we humans fly in air-conditioned comfort, how do these birds of a feather stay cool? 

Kasper Delhey and colleagues from the Max Planck Institute for Ornithology wondered. 

Using images of ten thousand world-wide bird species, they quantified feather colors — using pixels! The researchers explored the relationship between feather pigmentation and the birds’ flight itinerary. 

Results? Birds that migrate have significantly lighter-colored plumage than birds who prefer to stay home. Even if only traveling short distances! This finding was true for birds both large and small. And for birds who live on land and sea!

Why is this? Lighter plumage absorbs less light and prevents birds from overheating during migration! As temperatures become more extreme, these feathers may also be an indicator of climate change! 

Thanks for the fashion tip, birdies! Next time I fly south, I’ll bring a LIGHT jacket! 

Reference: Delhey, K., Dale, J., Valcu, M., & Kempenaers, B. (2021). Migratory birds are lighter coloured. Current Biology, 31(23), R1511–R1512. https://doi.org/10.1016/j.cub.2021.10.048