How the World's Smallest Birds Survive the Winter
"Little Arnold Schwarzeneggers," hummingbirds are tough—so tough they've evolved a clever way of coping with the cold.
As the smallest birds on Earth, hummingbirds may seem frail—so it's not surprising Donovan Nixon asked Weird Animal Question of the Week how they cope with winter.
Turns out these airborne jewels are as tough as diamonds.
In cold weather, hummingbird bodies enter into an "energy-conservation mode called torpor," according to Oregon State ecologist Adam Hadley. Birds that stay north for the winter experience a nightly "mini-hibernation," in which their 107-degree body temperatures can plummet to 48 degrees.
Heart rates also slow during torpor: The blue-throated hummingbird’s heart rate, for instance, drops from 1,260 beats per minute to 50 to 180 beats.
Hummingbirds can feed in chilly weather. Hadley has seen an Anna’s hummingbird visit his backyard bird
