Female Williamson's sapsucker (Sphyrapicus thyroideus) at its nest hole, Yellowstone National Park, Wyoming, United States of America, North America

Female Williamson's sapsucker (Sphyrapicus thyroideus), Yellowstone National Park, UNESCO World Heritage Site, Wyoming, United States of America, North America

Male Williamson's sapsucker (Sphyrapicus thyroideus) at its nest hole, Yellowstone National Park, Wyoming, United States of America, North America

Male Williamson's sapsucker (Sphyrapicus thyroideus) poking out of its nest hole, Yellowstone National Park, Wyoming, United States of America, North America

Female Williamson's sapsucker (Sphyrapicus thyroideus) on a feeding tree, Yellowstone National Park, Wyoming, United States of America, North America

Male Williamson's sapsucker (Sphyrapicus thyroideus), Yellowstone National Park, UNESCO World Heritage Site, Wyoming, United States of America, North America