Family-Animalia: Sittidae

Nuthatches are small, compact birds with short tails and long, strong bills. They have strong toes and claws, which enable them to climb up, down, and sideways on tree trunks and branches, probing for insects hidden in bark crevices. They do not use their tails to prop themselves up like woodpeckers and creepers. They sometimes stick a large seed in a crevice for support and then “hack” it open with their bills. This behavior earned them their name. Nuthatches are monogamous, and Washington’s species form long-term pair bonds. One species in Washington is a cooperative breeder, with helper-birds aiding at the nest. Nuthatches nest in cavities—some excavate their own, while others rely on natural cavities, old woodpecker holes, and to a lesser extent, nest boxes. The female generally incubates the eggs, and the male feeds her while she is on the nest. Both parents feed the young until a few weeks after they fledge.

Reference: BirdWeb