White-breasted Nuthatches (Sitta carolinensis) are one of the interesting and unique species we have the pleasure to live near.* Their coloration is elegant, a smooth blue-gray back with black accents on the nape and tail, a white face and belly with a rusty wash under the tail. They can often been seen making their way down a tree trunk head-first, occasionally lifting their head to have a look around before continuing their descent.
They use their slightly upturned bills to search within the cracks and crevices of the bark for insects, eggs, and larvae. They will also visit backyard feeders and can be seen foraging in mixed flocks with chickadees and titmice through the winter.
Although they seem to share a niche with woodpeckers, hanging around on tree trunks and looking for insects, White-breasted Nuthatches have their own unique adaptations that differ from those of their tappity-tapping brethren. While woodpecker toes are zygodactyl--with two toes facing forward and two facing backward, to facilitate clinging to a vertical surface--nuthatches, like other passerines, have the standard anisodactyl toe arrangement (three toes forward, one toe--the hallux--backward). This feeting arrangement is normally ideal for perching on small branches and twigs; nuthatches have a longer, stronger hallux and curved claws to keep a firm grip as they move down a tree. 
As cavity nesters, nutchatches rely on dead trees and snags for breeding. A pair of nuthatches is monogamous and territorial, remaining together year after year. They will usually raise only one brood per year, in late spring or early summer, with average of six eggs per brood.
Listen for their nasally yank yank yank in wooded neighborhoods and tree-filled parks and trails.
*Who am I kidding, every species is interesting and unique!
Resources/additional information:
- Birds of North America (Cornell Lab of Ornithology)
- Audubon Guide to North American Birds
