This hummingbird survives cold nights by nearly freezing itself solid
The black metaltail goes into a state of suspended animation, becoming ‘cold as a rock’
A black metaltail hummingbird (Metallura phoebe) perches on a branch in the Peruvian Andes. To survive cold nights, this bird cools down to 3° Celsius, putting itself in a state of suspended animation. It’s the coldest body temperature ever recorded for a bird or non-hibernating mammal.
GLENN BARTLEY/ALL CANADA PHOTOS/ALAMY STOCK PHOTO
By Jonathan Lambert
10 HOURS AGO
The high Andes mountains of Peru are a hummingbird’s paradise, rich in wildflower nectar and low in predators. But there’s one problem: the cold.
Nighttime temperatures often dip below freezing in these rainy tropical highlands. How does a six-gram bird that needs nectar from 500 flowers a day just to survive get enough extra energy to keep itself warm all night?
It doesn’t.
Instead, as temperatures drop with the sun, these hummingbirds enter a state of suspended animation known as torpor. One species, the black metaltail (Metallura phoebe), chills to 3.26° Celsius, the coldest body temperature ever recorded in a bird or non-hibernating mammal, researchers report September 9 in Biology Letters.
“They’re cold as a rock,” says Blair Wolf, a physiological ecologist at the University of New Mexico in Albuquerque. “If you didn’t know better you’d think they were dead.” Cooling to near-death temperatures lets the hummingbirds save precious energy, allowing them to survive the cold night and gear up to feed the next day, Wolf says.
More:
https://www.sciencenews.org/article/hummingbirds-black-metaltail-cold-torpor
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