Blue-gray Gnatcatcher
Blue-gray Gnatcatcher
Polioptila caerulea
At a Glance
A very small woodland bird with a long tail, usually seen flitting about in the treetops, giving a short whining callnote. Often it darts out in a short, quick flight to snap up a tiny insect in mid-air. Widespread in summer, its breeding range is still expanding toward the north.
All bird guide text and rangemaps adapted from by Kenn Kaufman漏 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
Old World Warblers and Gnatcatchers, Perching Birds
IUCN Status
Least Concern
Habitat
Arroyos and Canyons, Desert and Arid Habitats, Forests and Woodlands, Freshwater Wetlands, Shrublands, Savannas, and Thickets, Urban and Suburban Habitats
Region
California, Eastern Canada, Florida, Great Lakes, Mid Atlantic, New England, Northwest, Plains, Rocky Mountains, Southeast, Southwest, Texas
Behavior
Direct Flight, Flitter
Population
260.000.000
Range & Identification
Migration & Range Maps
Probably all in North America are migratory, with different individuals present in summer and winter. Some in Mexico and Bahamas may be permanent residents. Peak migration periods in many areas are April and September. May migrate by day.
Description
4 1/2 -5" (11-13 cm). Blue-gray above, whitish below, with white eye-ring. White outer tail feathers (tail looks all white from below). In spring and summer, male has thin black eyebrow.
Size
About the size of a Sparrow
Color
Black, Blue, Gray, White
Wing Shape
Rounded
Tail Shape
Long, Rounded
Songs and Calls
Song is a thin, musical warble. Call note a distinctive, whining pzzzz, with a nasal quality.
Call Pattern
Complex, Flat, Undulating
Call Type
Buzz, Chirp/Chip, Scream, Trill, Whistle
Habitat
Open woods, oaks, pines, thickets. Breeding habitat varies with region. In east, mostly in deciduous forest dominated by oak, ash, or maple, or in southern pine woods with understory of oak. In west, often in more scrubby habitat, including pinyon-juniper woods, chaparral, streamside trees, oak forest. Winters in wooded or brushy areas, often near water.
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Behavior
Eggs
4-5, sometimes 3-6. Bluish white, dotted with reddish brown. Incubation is by both parents, 11-15 days, usually 13.
Young
Female broods young much of time at first, while male brings food; later, both feed nestlings. Young leave nest about 10-15 days after hatching. 1-2 broods per year.
Feeding Behavior
Forages actively in trees and shrubs. Searches for insects among leafy outer twigs of deciduous trees and on branches and trunk in pines. Takes most food while perched, also hovers to pick items from surface, and often flies out to catch insects that it flushes from foliage. Large insects are beaten against a branch before being eaten.
Diet
Mostly insects. Feeds on a wide variety of small insects, including leafhoppers, treehoppers, plant bugs, leaf beetles, caterpillars, flies, small wasps, and many others. Also eats many spiders.
Nesting
Male arrives first in breeding areas and sings to defend territory and attract a mate. Courtship involves male leading female around to potential nest sites. Nest site is in tree, more often deciduous. Nest saddled on top of horizontal limb of tree, less often in fork of horizontal limb; height above ground is quite variable, 2-80' up, but 20-40' may be typical. Nest (built by both sexes) is a compact open cup of grass, weeds, plant fibers, strips of bark, lined with plant down, animal hair, feathers. Outside of nest coated with spiderwebs and decorated with pieces of lichen, making nest well camouflaged.
Climate Vulnerability
Conservation Status
Has expanded its breeding range through much of the northeast during the 20th century, and expansion may be continuing. Current population probably stable or increasing.
Climate Threats Facing the Blue-gray Gnatcatcher
Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.