Last winter we had our first ever red-breasted nuthatch at our bird feeders. The little mite zipped in and out from late November until late April, keeping his own company in as singular a fashion as our lone wintering song sparrow.
Was I merely dazzled by his rareness here to think him more attractive than his larger relative–the white-breasted nuthatch? He was a male because his cap was black, not gray like that of the female red-breasted nuthatch. Otherwise, he had the coloring of all red-breasted nuthatches–a black eye-stripe below a white stripe and a pleasing, rusty-red breast and belly. His back was the same silver-gray as the white-breasted nuthatch’s, but he was at least an inch smaller.
Red-breasted nuthatches prefer coniferous forests for living and breeding and were formerly known as Canada nuthatches because they are common residents in Canadian boreal forests. They particularly like fir and spruce species from the Pacific coast of British Columbia to the Atlantic coast of Nova Scotia and south along the Appalachians in the East and the mountains in the Southwest. However, they will settle for hemlock or pine, especially during the winter when they eat coniferous seeds in addition to their year-round diet of adult and larval insects and spiders.
But when the coniferous cone crop fails in winter, they sometimes head as far south as the Gulf coast of Louisiana and the deserts of northern New Mexico. They have even wandered across the Atlantic Ocean to Europe.
The red-breasted nuthatch is the only one of the four North American nuthatch species to engage in these irruptive movements. Usually they occur every two to four years, although at least a few red-breasteds move south of their breeding range every year.
Here in Pennsylvania, they are nearly always fairly common to common regular migrants in both spring and fall. The fall migration can begin as early as late August and continue through October. As Massachusetts ornithologist Winsor Marrett Tyler wrote in Arthur Cleveland Bent’s LIFE HISTORIES OF NORTH AMERICAN NUTHATCHES, WRENS, THRASHERS, AND THEIR ALLIES: “We begin to look and listen for them in early August and, if it is to be a nuthatch year, we have not long to wait before we hear the little trumpet call and see the tiny birds romping and rollickiing through the woodlands.”
And through the weeds, according to Richard F. Miller who reported a fall migration in northeastern Philadelphia back in 1914. “A remarkable feature…about the occurrence of this little SITTA [its genus name] here during that fall, was their habit of frequenting water courses fringed with dense growths of giant ragweeds in which they sought food on the thick stems, petioles and leaves, often feeding close to the ground…”
Probably the best description of a heavy fall migration was written by William Dutcher who observed a flight of red-breasted nuthatches on Fire Island Beach, New York, from September 21 to 23, 1906. “At the height of the migration, Nuthatches were seen everywhere–on buildings, on trees, bushes, and weeds and even on the ground…They crept over the roofs and sides of the houses, examining the crevices between the shingles; they searched under the cornices on the piazzas and in fact looked into every nook and corner that might be the hiding place of insects. Every tree had its Nuthatch occupant…On a large abandoned fish factory at least 50 of these birds were seen at one time..”
All of those red-breasted sightings were nearly a century ago. Yet on the Glenolden Christmas Bird Count in Delaware County during the high irruption winter of 1981-82, participants counted 325 red-breasted nuthatches, and last winter our neighbors, Charlie and Marge Hoyer, whose feeders are three miles as the crow flies from ours, had several coming to their feeders. Other birders throughout Pennsylvania were similarly reporting them.
To our disappointment, though, the pine siskins and common redpolls that usually accompany a red-breasted irruption here, did not appear. In the irruptive winter of 1995-96, which brought dozens of common redpolls and pine siskins to our feeders, a lone red-breasted nuthatch spent the last half of December and the first half of January in our hemlocks beside our stream in the company of dozens of black-capped chickadees. All of them were eating hemlock seeds on cold, snowy days.
Apparently, the late scientist, Lawrence Kilham, observed the same association between chickadees and red-breasted nuthatches in New Hampshire in the winter of 1972-73. Because hemlock cones are hydroscopic, meaning that they only open in dry, cold, and windy periods and close on warmer and more humid days, weather very much affects when birds forage on them.
Kilham reported no more than one pair of red-breasteds and anywhere from one to 25 chickadees with an average of four to eight. During a light snowfall, those species were joined by a white-breasted nuthatch and golden-crowned kinglets. My red-breasted also associated loosely with kinglets and white-breasteds, as well as tufted titmice. In the winter both resident and migratory red-breasteds may be solitary, as the one that visited our feeder was, form small flocks, as the Hoyers’ did, or join mixed-species flocks.
They also seem to join mixed-species flocks when they migrate north. After a common redpoll/pine siskin irruption in the winter of 1998, during which I saw no red-breasteds, spring migration was fantastic. The best day was the seventh of May when I sat on Dogwood Knoll surrounded by migrating birds. Dozens of yellow-rumped warblers, some within a few feet of me, snapped insects from the air, foraged among leaves on the ground, and sat on black locust branches at eye level. Red-breasted nuthatches called from all directions. Many least flycatchers and a few Nashville, blue-winged, and blackburnian warblers joined the yellow-rumps and red-breasted nuthatches.
I can usually count on seeing red-breasteds during spring migration from the second week of April through the second week of May, but so far none have discovered and nested in our two-acre Norway spruce plantation. Once the hemlock and white pine forests were cut in Pennsylvania, breeding red-breasted nuthatches were scarce, but the conifer plantations of spruce and pine planted in the 1930s started to increase breeding habitat for them by the 1960s. Today, they breed in isolated spruce plantations as far south as York County, west in Beaver County, and even in urban Allegheny and Philadelphia counties, although the Poconos probably have the largest breeding population because of their native black spruce trees.
Red-breasteds form pairs on their breeding grounds, either during the winter, if they don’t migrate, or as soon as they return. In addition to courtship flights, in which the female usually chases the male in slow motion, courtship-feeding only occurs if the female vocalizes, or sings for her supper, so to speak. While engaged in courtship flights, feeding, and subsequent mating, they also begin excavating a nest cavity in dead or partly dead trees. The female does most of the work while the male brings her food and watches out for rivals and/or predators.
The only red-breasted nest I ever saw was at the Stanwood Wildlife Sanctuary in Ellsworth, Maine. Cordelia Stanwood, an amateur ornithologist and photographer during the early twentieth century, provided some of the best nesting information about red-breasteds. It was she who noted that they “tap over each dead tree to find a suitable nesting quarters” and that one pair that she followed for several days “attempt[ed] to excavate a cavity in four or more trees before they found the site that best suited them.”
She and other observers also watched them smear their nest entrance with resin from spruce, balsam fir, or pine trees when they were finished building, and continually reapply it outside and inside the nest cavity throughout the incubation and nestling periods. They carry resin globules in on their bills and sometimes use small pieces of bark to apply the resin. This unique behavior trait is probably a deterrent to possible predators and competitors and rarely seems to harm either the parents or the young.
The female incubates between five and eight whitish eggs while the male feeds her both on and off the nest during the 12 to 13 days it takes the eggs to hatch. Then both parents feed the young exclusively insects for the 18 to 21 days they remain in the nest.
That is when I found the nest at the Stanwood Wildlife Sanctuary. As I watched the parents feeding the nestlings, I felt a bond with Stanwood who had watched from a blind as a pair fed their young. “They came and went constantly,” she wrote, “sometimes caterpillars dangled from their beaks, at other times their bills bristled with crane-flies or moths. Once a bird carried in a large white grub, at another time the larvae of a spruce bud moth, and still again spruce bud moths themselves…”
Once they fledge the parents continue feeding them for at least two weeks and sometimes longer. Not much is known about either juvenile survivorship or how they disperse after they finish breeding, but a few observers have reported that most youngsters leave their parents’ territory and strike out on their own. They may also make up a large portion of the red-breasted nuthatches that migrate south.
Here on our mountain, red-breasted nuthatches are like tiny magicians that pop up when you least expect them and then, just as quickly, disappear. But whenever I hear their tinhorn call, I am hopeful that they will someday find our spruce grove and set up housekeeping for the summer.