This hummingbird survives cold nights by nearly freezing itself solid
Published in Uncategorized.
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?
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.