Adapted for Cold
Rufous Hummingbirds are well adapted to cold temperatures. This allows them to migrate into areas where night time temperatures in early spring may drop below freezing. They can survive sudden cold and snows typical in springtime. Many hummingbirds use torpor occasionally to survive cold nights, but Rufous Hummingbirds routinely go into torpor at night, probably because it may freeze at night even in July in their nesting grounds in Canada and Alaska.

D Repasz