A female Anna’s hummingbird sits in a dormant tree in winter. Hummingbirds have the ability to go into torpor – a very deep sleep state – to conserve energy on really cold days and nights.
A female Anna’s hummingbird sits in a dormant tree in winter. Hummingbirds have the ability to go into torpor – a very deep sleep state – to conserve energy on really cold days and nights. File photo
A female Anna’s hummingbird sits in a dormant tree in winter. Hummingbirds have the ability to go into torpor – a very deep sleep state – to conserve energy on really cold days and nights. File photo