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All fire and no rain makes fairywrens very dull birds. As the climate warms and wildfires become increasingly common, these birds are coping by ditching their bright plumage to better blend in with the burnt landscape.

at Washington State University in Pullman was studying the physiology of the red-backed fairywren (Malurus melanocephalus), an energetic little bird native to the grasslands of northern and eastern Australia, when he and his team made this discovery.

鈥淚 was in the middle of another experiment when this wildfire came through and burned up all of the breeding territories,鈥� he says.

With all of the nest sites burned just before the birds鈥� breeding season, Boersma and his colleagues decided to shift focus.

They observed the birds move into their breeding season and noticed that the males, which typically become more vibrant at this time, with jet-black feathers and the eponymous splash of red across their backs to attract females, just didn鈥檛. Instead, they stayed drab and brown. Even the older males that didn鈥檛 have many remaining breeding seasons simply sat it out.

The researchers had taken blood samples from the birds before the fire and compared them with samples after the nesting sites had been destroyed. They found that the drab male birds had suppressed testosterone levels, but all other signs pointed to good health.

鈥淭his is a species that鈥檚 adapted to fire because it evolved in savannahs that tend to burn,鈥� said Boersma. He argues that if there is no place for the birds to nest, it might not be worth the risk of switching to bright colours that may catch the eye of a hungry predator. Instead, delaying or skipping the breeding season altogether would be a safer bet.

The fairywrens are clearly no strangers to fire, but what remains unclear is exactly how skipping consecutive breeding seasons due to droughts and increasingly intense fires will affect the birds鈥� population numbers in the future.

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