Peru The flyfly Metallura phoebe cope with cold nights in the mountains thousands of meters by lowering its body temperature from 40 degrees C to 3.26 degrees Celsius.
Hummingbird Metallura phoebe. Photo: Glenn Bartley.
The Peruvian Andes highlands are hummingbirds’ paradise with abundant natural nectar and few predators, but they face below 0 degrees Celsius cold at night. When the temperature drops, the hummingbird enters a lethargic state. The researchers found that hummingbird Metallura phoebe self-cooled to 3.26 degrees Celsius, the lowest body temperature ever recorded in birds, according to a report published on 9/9 in the journal Biology Letters.
“The hummingbird body is ice cold,” said Blair Wolf, an ecologist at the University of New Mexico in Albuquerque, USA. “If you don’t know, you might think they’re dead.” Wolf explains that hypothermia to near freezing helps hummingbirds save energy, allowing them to survive a cold night and return to normal feeding the next day.
Lethargy has been observed in hummingbirds before, but Wolf et al. Wanted to find out in more detail. They put 26 hummingbirds in collection