If I chose one species in our yard that is truly our neighbor, it would be the White-breasted Nuthatch. This species does not migrate and pairs remain territorial all year. It is likely that the white-breasted nuthatches I saw nesting in May, accompanying fluffy fledglings to our feeder in July, and calling from our woods in October are the same two individuals. They visit our feeders faithfully all winter, taking sunflower seeds or bits of peanut away to jam into window trim, siding, or porch wood, squirreling food away in case it is needed.
We have had a pair of white-breasted nuthatches nesting in a cavity in a green ash tree for many summers. The tree extends a gnarled branch across the driveway and the birds can be seen patrolling its bark, foraging for scale insects, the larvae of other insects, or spiders. The nest cavity was probably hollowed out by woodpeckers. White-breasted Nuthatches are secondary cavity nesters. Unlike woodpeckers or red-breasted nuthatches, they don’t excavate themselves, but may fine-tweak an existing hole. As “our” pair demonstrate, a nest cavity is often reused in following years.
The female is the nest builder. She first lines the cavity with bark, fur or lumps of dirt, and then builds a cup nest from shredded bark, fine grasses and feathers. She lays 5-9 eggs in this nest and incubates them for 13-14 days. After they hatch, nestlings remain in the nest 26 days. Dr. Roberts called the nuthatch a “close sitter,” which often meant that he could approach a nest, stick his hand in the hole and lift the bird off the nest to observe the eggs, without her flying off White-breasted Nuthatches have only one brood per season.
White-breasted nuthatches also rely on tree cavities for night roosts. Individuals hole up, one per cavity, although on bitterly cold nights, they have been known to snuggle together. One record roost cavity held 29 birds! A nest cavity isn’t used for roosting, so that’s three separate holes in trees that a pair requires. This is a compelling reason to keep those dead snags standing. I think our yard birds might also use the interior of purple martin gourds for roosting. I have seen a nuthatch on several occasions fly to a gourd and squeeze into the opening just at dusk.
Two idiosyncratic behaviors distinguish nuthatches from others. One is the ability to move headfirst down a tree while foraging. Only nuthatches can do this. Members of the Nuthatch family, Sittidae, are distributed all over the world, and they all do this. The behavior is considered adaptive, because on their downward trip, they view the bark from a different perspective, perhaps gleaning insects that other bark foragers missed.
The second is the propensity of nuthatches at feeders to snatch morsels and wedge them elsewhere, caching them for future use. Returning, they use their point little beaks to hammer at the nut breaking it apart into usable pieces—thus the name, nut-hatch. They are known to steal other birds’ caches, too. And winter behavior studies have shown that if a nuthatch pair at the feeder are startled, each bird will fly in an opposite direction so that another species, looking on, can’t tell where their stashes are.
White-breasted Nuthatches prefer mature deciduous woods, in keeping with that need for tree cavities, but they’re flexible. They can also be found on forest edges, in parks and suburban back yards. Their range runs coast to coast, the northern limit being just north of the U.S. northern border and their southern limit running into Mexico’s interior. They are absent from the treeless Great Plains and the semi-arid parts of the Great Basin.
Non-migratory species are faring better than migrating birds in our warming world, and this is true for White-breasted Nuthatches. Their population has been estimated at 10 million breeding adults, and the Breeding Bird Survey 1967-2019 recorded a healthy 1.54% increase in Minnesota. Minnesota’s Breeding Bird Atlas attributes the increase to the maturing of shade trees planted in residential areas and to the widespread practice of feeding birds in winter.
As I’ve written this, I ‘ve watched our male fly back and forth from feeder to maple tree, wedging nuts in its bark. In only a few weeks, I’ll hear him singing his territorial song: (https://www.allaboutbirds.org/guide/White-breasted_Nuthatch/sounds— try the song from New York state). He’s declaring that life is good on Pioneer Lake.
Recent Comments