Red-breasted nuthatches are often a challenging and favorite bird for local birders. Many are probably more familiar with their relative, the white-breasted nuthatch, which is a very common deciduous forest and feeder bird. Most who see red-breasted nuthatches find the winter visitors, which can be very abundant during sporadic irruption years. Unlike seasonal migration, irruption years are unpredictable and result from less food (seeded pinecones) availability near breeding habitat and large numbers of nuthatches move south. Some of these visitors do carry-over nesting but only following an irruption year. Aside from irruption years, most red-breasted nuthatches breed and remain much farther north. However, there are separate populations of resident red-breasted nuthatches that breed locally in our area of Pennsylvania and other sections of the Appalachian Mountains.
They breed in Boreal forest conifer habitats that are often found on the north sides of mountains, along mountain streams, or in conifer swamps or sphagnum bogs. In Pennsylvania, hemlocks are generally the dominant tree species along with spruce, pine, tamarack larch, and fir. These sheltered micro-climates stay cooler during breeding season in late spring and early summer. Red-breasted nuthatches share this habitat with other Boreal forest species such as golden-crowned kinglets, dark-eyed juncos, and several warblers: including blackburnian, black-throated green, and yellow-rumped, among other species. Some of these species are becoming more common, thanks to habitat recovery. Most Boreal forest habitat was clear-cut in Pennsylvania and very little was left by the early 20th century. Since then, much of the habitat has been preserved and continues to mature. Despite important conservation successes, there are long-term threats to the habitat such as climate change and the invasive hemlock woolly adelgid, which is killing many hemlocks, a crucial species.
Following a non-irruption year, this spring and summer presented a good opportunity to observe local breeding populations since any red-breasted nuthatches are likely breeding residents. For the last several years, I have been able to consistently find breeding pairs in several different locations of Bald Eagle State Forest. As recently as 5-10 years ago, it was difficult to find any red-breasted nuthatches after a non-irruption year. They can also be found at Rickett’s Glen State Park and other locations where the right habitat exists. Red-breasted nuthatches are also known to intermittently nest at lower elevations in large stands of planted conifers. After breeding, many nuthatches disperse and can no longer be reliably found on breeding territory.
Finding summer breeding populations can be challenging as numbers are smaller and behavior is different. Their primary diet consists of insects in contrast to seeds during the winter, so they tend to stay closer to tree trunks, often very high. The best way to find them is to listen for their distinctive nasal “yank” calls and song. Spotting juvenile birds is often a better way to confirm breeding as nests can be well-hidden. Juveniles are smaller and have a duller colored breast, more like the paler red or orange of females while males have a very distinctive bright red breast. The black stripe through the eye can be a more reliable field mark to distinguish them from white-breasted nuthatches. In addition to enjoying our breeding red-breasted nuthatches, we can also look forward to the next big irruption year when they will again be abundant and easy to find in winter.
Michael McGuire is an active board member of Seven Mountains Audubon Society in Lewisburg. He has a long interest in birding and a passion for bird and nature photography. He does computer programming and designed and currently manages the local chapter website sevenmountainsaudubon.org. He has recently taken a specific interest in observing bird species and their close relationships to unique local habitats that have a need for conservation.
BIRD LORE is produced by the Lycoming Audubon Society (serving Lycoming and Clinton Counties) and Seven Mountains Audubon (serving Union, Snyder, Northumberland and Columbia Counties). Information about these National Audubon Society chapters can be found at http://lycomingaudubon.blogspot.com and http://sevenmountainsaudubon.org