Bird of the month: White-breasted nuthatch

The white-breasted nuthatch is often observed walking and probing head-down on the trunks of large conifers in mature wooded areas.

The first impression is a small bird with a very white head and breast. It is the largest of the three nuthatches that are year-round residents in our area. It is a compact, short-tailed bird with a long, sharply pointed bill and is 5½ to 6 inches long. The red-breasted and pygmy nuthatches are both less than five inches. 

It has a blue-grey back, white face and breast, and chestnut colored undertail coverts and lower belly. When it spreads its tail, there are white stripes on the outer edges. It has a narrow black cap or stripe on the head and nape; in females this is a dark grey. 

Mature forests of conifers or deciduous trees are the preferred habitat. The white-breasted nuthatch feeds mainly on insects during the warmer months and switches to seeds and nuts during the winter. It enjoys suet and sunflower seeds at birdfeeders. 

I recently observed one hanging upside down on my suet feeder for a period of no less than five minutes. Was it taking a nap or just guarding its food source from other birds? 

It is a bark forager and uses its long bill to probe for insects on trees. It also uses trees as a food storage area, tucking seeds and insects into crevices in the bark or under loose pieces of bark for future use. The name “nuthatch” comes from its habit of jamming large nuts (such as acorn or hawthorn) or seeds into crevices in tree bark and then hacking and hammering them with the sharp bill to open or “hatch out” the seed or nut from its casing.

The voice is loud and nasal; although a bit less harsh than the more common, red-breasted nuthatch. It gives a rapid, low “wha-wha-wha” or “ank-ank-ank” call, like that of the red-breasted nuthatch, but a bit faster and not quite as loud. This insistent call matches its aggressiveness. These tough little birds will challenge birds larger than themselves for food and territory.

White-breasted nuthatches are usually solitary or in pairs, although they do join other groups of mixed nuthatches, chickadees, and woodpeckers in the winter months, especially at bird feeders. 

The pairs remain together throughout the year. Courtship begins by late winter. The male raises its head, spreads its tail, drops its wings, and sways back and forth and bows. To show what a good provider he is, courtship can also include the male bringing food to the female. 

They use existing holes in trees or old woodpecker holes for nests. The nuthatch lines the cavities with fur and fine bark and then adds a softer, inner layer of grasses, weeds, and feathers. Five to nine spotted, pink to reddish-brown eggs (less than an inch long) are laid. The incubation period is just under two weeks and the nestling period is about 26 days. 

Nuthatches actively protect their nests by using chemical odors to ward off predators. They may sweep around their nest holes with beetles or other insects that contain chemicals that act as repellants to squirrels. They also have been known to use cigarette filters or butts in their nest area to act as deterrents.

The white-breasted nuthatch is common and has a year-round range of most of the continental United States and southern Canada. Populations appear to be stable and are of low conservation concern. However, since they are cavity nesters who depend on dead or partially dead trees for nesting, too much removal of these trees by overzealous felling or pruning could put them at risk in the future.