AUGUST 23, 2019
by Silvia Dropulich, Monash University
Most birds remain the same color year-round, replacing their feathers only once a year.
But some birds undergo a seasonal color change and replace some of their feathers twice each year—often alternating between dull and bright feathers.
Now an international study led by a research team from the Monash University has discovered why.
The researchers tested the evolutionary drives of seasonal color change in birds from around the world. Their findings are reported today in, Ecology Letters.
The study found that seasonal color change in birds evolved in species where birds are under pressure to be colorful for sexual attractiveness but also face high predation risk, where it is better to be dull to avoid detection.
"This trade-off is a classic problem in ecology, and studying color change in birds gives insight into how animal colors evolve," said study author Associate Professor Anne Peters, from the School of Biological Sciences.
"The results suggest that seasonal color change is an adaptation that allows birds to have the best of both worlds: they can be sexually attractive and bright while breeding, but also dull colored and difficult to detect by predators outside the breeding season."