Gabriel Rojo / Green-barred woodpecker (Colaptes melanochloros) female on snag, La Pampa, Argentina

Ole Jorgen Liodden / White-tailed eagle (Haeliaeetus albicilla) perched on snowy snag with wings raised, Flatanger, Norway, January.

Gerry Ellis / Cheetah (Acinonyx jubatus) standing on dead tree branch, Masai Mara, Kenya

Thomas Mangelsen / Bald Eagle (Haliaeetus leucocephalus) adults on snags, North America

Thomas Mangelsen / Bald Eagle (Haliaeetus leucocephalus) adult perching on snag, North America

Konrad Wothe / Eastern Chipmunk (Tamias striatus) on snag, North America

Michio Hoshino / Bald Eagle (Haliaeetus leucocephalus) perching on a snag, Alaska

Michael Quinton / American Robin (Turdus migratorius) parent feeds grasshopper to chicks in nest cavity at top of a snag, summer, Idaho

Michael Quinton / Great Gray Owl (Strix nebulosa) brooding female with chick in nest cavity at top of snag in the summer, Idaho

Michael Quinton / Great Gray Owl (Strix nebulosa) parent with owlets in nest cavity at top of snag, Idaho

Michio Hoshino / Bald Eagle (Haliaeetus leucocephalus) trio sitting on snag, Alaska

Michio Hoshino / Bald Eagle (Haliaeetus leucocephalus) pair landing on snag, Alaska