Brown-headed Nuthatch (Sitta pusilla)

Distribution

Year round range: Southeastern United States, extending east from southeastern Oklahoma and eastern Texas across central Arkansas, Tennessee, and the Gulf Coast states, to southern Maryland and Delaware, Virginia, south to southern Florida; also found in the Bahamas on Grand Bahama. Highest breeding densities in western South Carolina, western Georgia, central Florida, and southern Mississippi; nearly extirpated from Grand Bahama.

Breeding habitat

Endemic to the southeastern pine ecosystem, occurring almost exclusively with pines in a wide variety of Southeastern pine forest habitats. Most often uses the loblolly-shortleaf pine forests of the Upper Coastal Plain and longleaf-slash pine forests of the Lower Coastal Plain. Within these forest types, this species is most common in open, mature or old-growth forest, particularly where natural fire patterns have been maintained.

Conservation status

Because of its restricted overall range, its dependence on mature pine-savannah habitats, and its declining population trend (45 % decline overall since 1966), the Brown-headed Nuthatch is a species of high conservation importance. Healthy populations of this species occur in association with the endangered Red-cockaded Woodpecker. Understanding the effects of habitat fragmentation and large-scale silvicultural practices are important to its long-term conservation.

Description

Male: A small nuthatch with a brown cap and narrow, dark eyeline; a white spot on the back of the neck is visible at close range. The wings, back, and tail are grayish; the underparts are buffy white.

Female: Same as adult male.

Juvenile: Same as adult male.

Vocalizations

Songs and calls: As most vocalizations are given in a variety of circumstances, distinctions between songs and calls are unclear. There are four types of vocalizations:

“Rubber Ducky” vocalization: A high-pitched, squeaky, wheezy two-syllable sound, tyah-dah or chee-da, strikingly like a toy rubber duck. Carries long distances, and given in a wide-array of circumstances.

Serial vocalization: A rapid series of notes, softer than Rubber Ducky Vocalization, but more emphatic. Most often given when birds are fairly close together, either during times of apparent excitement or normal foraging.

Single-note vocalization: Extremely soft single notes such as tip, pik, tut, or dep. Often used as a contact call among individuals.

“Schweee” vocalization: A soft, thin, airy, and harsh schweee, schweee, schweee; given by birds soliciting food from mate.

Foraging strategy

Forages actively among pine trees throughout daylight hours, methodically seeking out arthropods on or underneath tree bark in summer. Primarily hops along tops of limbs in zigzag fashion, peering down around limb first on one side, then on the other. Most often moves distally along limbs, and may climb up or down trunks. Inspects bases of needle clusters and bracts of cones for seeds and arthropods. After finding a seed or large insect, the bird flies or hops to a nearby limb and begins feeding.

Diet

Takes a wide variety of insect prey during warmer months, including bark-dwelling cockroaches, spiders, beetle larvae, and insect egg cases; mainly eats pine seeds from cones during colder months.

Behavior and displays

• The weak and slow flight, with a discrete series of wing-beats, results in a flight pattern of shallow dips.

• Birds roost at night either in cavities or on pine branches out in the open.

• Interspecific interactions may include supplanting individuals from perches, attempting thefts of food, in-flight pursuits, and fighting with physical contact. In one instance, a fight between two birds resulted in one bird hopping atop the other and pecking viciously at its back and tail until they both tumbled through the air.

• Immature males from previous nesting attempts may help at the nest, assisting with cavity excavation, nest construction, nest sanitation, and feeding of nestlings, fledglings, and the female at the nest. They may also chase intruding birds from the territory.

Courtship

• Female performs “wing-quivering displays” and emits begging calls as the male brings food.

• Both sexes may quiver wings and twitter at nest site, although usually only female begs. Early in the breeding season, female is mate-guarded by male as she forages from tree to tree.

Nesting

Nest Site: A primary cavity nester; snags for nesting occur naturally in southeastern pine forests because of fire, in open areas adjacent to pine woods, or in wet pine savanna or ponds because of flooding. Artificial sites used include nest boxes, fence posts, telephone poles, and wooden pilings in residential or rural areas.

Height: Nest heights are among the lowest of any North American cavity nester, generally between 2–10 feet (0.5–3 meters), but can range up to 90 feet (30 meters).

Nest: Places a bed of soft materials, including bark shreds, grasses, forbs, wood chips, hair, feathers, pine seed wings, and cocoon fibers, inside a cavity. Usually excavates nest cavity in dead wood, but may reuse an old cavity, enlarge an existing cavity created by other nuthatches or woodpeckers, or use an artificial nest box. Helper may assist in nest construction.

Eggs: 3–9, usually 5–6, white, light creamy, or buffy eggs marked with reddish brown, vinaceous cinnamon, purplish, or lavender. Markings are either evenly distributed as fine dots or concentrated at larger end as blotches.

Incubation period: 13–15 days, incubation by female only, though the male may regulate incubation rhythm by calling female off nest. Male continues to feed mate at nest site during incubation, additionally, helper may feed female at nest.

Nestling period: For the first few days, the female broods roughly half the time, then only sparingly. Both parents attend the young, bringing small, soft-bodied arthropods as no food is regurgitated; helper may also feed nestlings and aid in nest sanitation. Young leave nest after about 18 days.

Fledgling period: Fledgings are dependent on food 2–4 weeks after leaving the nest, so parents feed young for another 24–26 days, a helper (young male) may also tend young. Family groups remain together throughout summer, and may merge with other family groups.

Broods: Second broods sometimes occur.

Cowbird Parasitism: Not known to occur.