November 08, 2024
ON THE WING

Nuthatches named for habit of prying seeds out of shells

I watched the white-breasted nuthatch as it flew to the feeder, selected a sunflower seed, and flew to the trunk of a white pine tree. It turned itself so that it was facing downward and descended the tree in this fashion for several inches. It reached a certain spot, stopped, and neatly wedged the seed into a crevice.

Having secured its food item, it began to methodically pry the seed out of its shell; this behavior gave it and its relatives its name: “nuthatch.” Once it finished, it returned to the feeder and began carrying seed away, storing it for future emergency supplies.

Caching food, or what researchers refer to as “scatterhoarding,” is a common practice of nuthatches. The white-breasted nuthatch has a large territory – between 25 to 45 acres – and will store only one food item in a particular location. After watching these nuthatches visit my feeders frequently throughout the day, I imagined hundreds of black-oil sunflower seeds tucked behind innumerable bits of bark on dozens of trees. They sure don’t put all their eggs in one basket.

As do all nuthatches, the white-breasted nuthatch has specialized feet and legs for climbing vertical surfaces. Their legs are very strong; their feet have very long, sharp nails that enable them to cling to almost any surface, even upside down. Their toe arrangement, unlike that of woodpeckers (which is zygodactyl – two toes forward, two toes backward) is termed “anisodactyl” – three toes point forward, one points backward. This rear digit has the longest nail, which gives the bird additional grip and support.

The white-breasted nuthatch is our largest North American nuthatch, at about 6 inches. It also has a distinct appearance that makes it easy to distinguish from its relatives at a glance. Like the other nuthatches, it has a dark crown; unlike the others, this coloration does not extend to the face. This gives it a very “clean” look. Its plumage, overall, is more monochromatic, lacking the ruddy wash of a red-breasted nuthatch and the muted browns of a pygmy or brown-headed nuthatch. It does have a slight chestnut tinge to its undertail coverts and flanks, which is not readily noticed. The overall effect is of austere elegance.

This nuthatch prefers deciduous or mixed deciduous-coniferous forests and is more comfortable around woodland edges and open areas than is the red-breasted nuthatch. Consequently, it is most often seen intown, and I almost always see them around the University of Maine campus. In contrast, I have to visit the University Forest to see red-breasted nuthatches.

Also, unlike red-breasted nuthatches, the white-breasted is largely nonmigratory. Researchers have found that a mated pair will remain together on their territory throughout the year, sometimes sharing a portion of that territory with another pair.

This brings us to another interesting difference: nesting requirements. White-breasted nuthatches will use existing cavities, such as old woodpecker holes or, in some cases, nest boxes. Red-breasted nuthatches prefer to excavate their own cavities.

In either case, it is always a good idea to let dead or dying trees remain on your property or woodlot whenever possible. These provide much-needed shelter and food for both nuthatches and other birds – a living “nursery.”

Chris Corio, a volunteer at Fields Pond Audubon Center in Holden, can be reached at fieldspond@juno.com


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