a little upside-down bird
by Darcy Thomas
Once called the Canada Nuthatch, the Red-breasted Nuthatch Sitta canadensis is a common bird throughout North America. The name nuthatch is likely from the word “nuthack”, referring to the nuthatches habit of hacking away at a seed with its bill to open it. For such a tiny bird it gets your attention with its “tinhorn” yank yank call that can be heard year-round in coniferous forests. Red-breasted Nuthatches prefer fir and spruce forests but can be found in a forest mix including pine, hemlock, larch, western cedar, aspen and poplar. If you have watched them, you know these little birds are an intense bundle of energy in constant motion probing for insects and seeds on trunks and tree branches. They like to travel through tree canopies with a mixed flock of chickadees, kinglets, and woodpeckers. They are called “a little upside-down bird” due to their ability to move up and down headfirst along tree trunks. They are also talented at moving sideways. The foot of the nuthatch has one big toe called a hallux that faces backward. This enables it to walk headfirst down tree trunks by moving one foot at a time while the hallux toe on the other foot holds firmly to the bark.
The Red-breasted Nuthatch is the only nuthatch in North America to have large irruptive flights when there is a shortage of winter food on their breeding grounds. This sometimes drives them hundreds of miles to the south to the Gulf Coast or the deserts of northern Mexico. They also have the distinction of being the only North American nuthatch to have crossed the Atlantic to Europe as a vagrant.
A small, compact bird with practically no neck and a short tail shaped somewhat like a chubby cigar with a long bill, the Red-breasted Nuthatch is only 4.3” long and weighs only 0.4 oz. Males are a beautiful blue-gray with a rich reddish-cinnamon on the underparts. The head sports a strong pattern with a black cap and a black stripe through the eye with a white stripe over the eye. The adult female is similar but with blue-gray on the top of the head rather than black and the black parts are paler with the eye stripe not quite as wide.
Red-breasted Nuthatches are cavity nesters. The female selects the tree and both parents excavate the hole. While the female does most of the work the male makes up for this by feeding her while she excavates. It is quite remarkable when you think about it. Nuthatches don’t have strong stiff tails to support them while they work like woodpeckers do. They also do not have chisel-like bills. They lack the large muscular body that helps woodpeckers hammer. Instead, they have persistence. They remove minuscule wood chips one piece at a time until the work is done. The nest is built with grasses, strips of bark and pine needles. Sometimes they steal nest-lining material from the nests of Pygmy Nuthatches and Mountain Chickadees. They aggressively defend the nesting cavity, especially while building it and can chase away birds much larger than themselves, like Downy Woodpeckers and pesky House Wrens. Resin is collected from conifers and plastered around the entrance to the cavity. They carry the resin in the bill or, in a remarkable example of tool use, on pieces of bark used as applicators to spread the resin. The resin may prevent predators or competitors from getting into the cavity. One would think the nuthatch would stick to the resin, but it avoids this by diving headfirst into the hole. It’s a terrific feat of agility.
During the summer, Red-breasted Nuthatches primarily eat insects, beetles, caterpillars, spiders, ants, and earwigs. The nestlings thrive on these foods. During spruce budworm outbreaks Red-breasted Nuthatches enjoy a feast. Nuthatches cache conifer seeds and insects in the bark of trees to help them get through a cold winter. They shove this food into bark crevices and often cover them with pieces of bark, lichen, or pebbles to hide them.
While numbers of Red-breasted Nuthatches are probably stable, and their breeding range has expanded southward in some eastern states, it is important to leave some dead trees standing in forests to provides places for nests. They readily visit bird feeders eating peanuts, sunflower seeds, and suet. They take the bigger pieces to a tree, jam them into the bark, then hammer them open so they can eat. Once bears are hibernating put your bird feeders up and get ready to enjoy these pretty little upside-down birds from your cozy house on a cold winter day.