Bird's-Eye View: Nuthatch is a little bird with a big tree trick

It's that little bird that often climbs down the trunk of the tree head first. The only bird that is able to do so, it is the nuthatch's foot structure that makes this behavior possible. It has two toes facing forward and two facing back, so when it's perched on a branch, two toes are on either side. This means that as the bird is going down the tree head first, the two hind toes on each foot keep it from falling head over …toes. Placement of the feet helps, too. The nuthatch places one foot forward of the other as it is climbing down and that helps it keep from tipping over. Woodpeckers have a similar foot structure, but they haven't quite figured out how to do this maneuver.

There are four nuthatch species found in North America, and two, the White-Breasted and the Brown-Headed, are found all year in our area. The White-Breasted Nuthatch is the most widespread of all four species. It breeds and spends the entire year in all 48 contiguous states. The Brown-Headed Nuthatch is strictly a bird of the Southeastern states. The Pygmy Nuthatch is closely related to the very similar Brown-Headed, but it is found primarily in the Western states.

Different ways of nesting

The Red-Breasted Nuthatch lives in the coniferous forests of Canada and the Western states. In winter, it sometimes visits the Southeast and the southern Plains states. It is also one of those few species that inhabit the higher elevations of the southern Appalachian Mountains, where the climate and ecology are more like the northern parts of its range.

All four North American nuthatches are cavity nesters, but they employ different means of getting a nest. The White-Breasted is a secondary cavity nester. That means that it does not excavate the tree cavities it uses for nests and for roosting, but uses cavities made by primary excavators, the woodpeckers. It will also use other naturally occurring cavities or artificial ones such as nest boxes on occasion. The Brown-Headed usually excavates its own nests, but it will sometimes use an existing cavity such as an old woodpecker nest or a nest box.

These two birds also have different feeding strategies. The White-Breasted lives in deciduous forests or mixed deciduous/coniferous forests -- including suburban neighborhoods -- where it uses its unique methods of getting around by foraging on the trunks of trees and the major branches searching for all sorts of insects, ants, gypsy-moth larvae and tent caterpillars. In winter, when insects are scarcer, it relies more on such plant material as acorns, corn and sunflower seeds from bird feeders.

The Brown-Headed Nuthatch, a smaller and more agile bird, tends to explore for food at the ends of branches among the needle clusters and cones of the pines that this bird prefers.

In winter, both White-Breasted and Brown-Headed Nuthatches often join foraging flocks. These are groups of birds of several species that travel about in search of food. The groups are often comprised of chickadees, titmice, Downy Woodpeckers, Yellow-Rumped Warblers, Pine Warblers, Brown Creepers and both Ruby-Crowned and Golden-Crowned Kinglets. These foraging flocks probably benefit these birds in two ways: by increasing their chances of finding food and by warning each other of the presence of such predators as Sharp-Shinned Hawks that feed primarily on small birds.

Awareness of this concept of foraging flocks can help winter bird-watchers see more birds. Small, mixed flocks of chickadees and titmice are common. When you see such a flock, watch it closely and one or more of these other species may be following along, too.

Familiarity with their vocalizations can help you find nuthatches and their foraging collaborators, too. The White-Breasted Nuthatch has a characteristic nasal yank-yank-yank call. The Brown-Headed makes a two-note call that sounds like a child's toy. It is called the Rubber Ducky vocalization and sounds like a rubber duck squeezed and released, usually three times in rapid succession -- chee dah, chee dah, chee dah.

Both White-Breasted and Brown-Headed Nuthatches are easily attracted to bird feeders, where they will feed on sunflower seeds and suet. Now that fall has arrived, the insect prey of these birds is beginning to diminish, and they will soon rely more on seeds. This is a great time to put those bird feeders up and prepare to enjoy these unique and entertaining nuthatches.

□ Forsyth County Parks and Recreation will sponsor free bird walks at Triad Park, 9652 W. Market, Kernersville from 9 to 10 a.m. on Wednesday and Nov. 19. Call 996-1409 for more information. Also offered free of charge is the basics of bird-watching, from 2 to 4 p.m. Sunday, also at Triad Park in Kernersville.

■ Bird's-Eye View is a joint column by Ron Morris and Phil Dickinson. Today's column was written by Morris. Morris retired after 24 years as the curator at the N.C. Zoo. He has studied birds around the world and is currently the vice president of the Audubon Society of Forsyth County. Dickinson is a legal writer. He has been an active birder for 15 years, and is a past president of the Audubon Society of Forsyth County and heads the conservation committee. If you have a birding question or story idea, write to Bird's-Eye View in care of Features, Winston-Salem Journal, P.O. Box 3159, Winston-Salem, N.C. 27101-3159, or send an e-mail to birding@wsjournal.com. Please type "birds" in the subject line.