Mexican Jay
Mexican Jay
Aphelocoma wollweberi
At a Glance
Widespread in Mexico, this bird enters the United States in two areas: in much of southeastern Arizona and adjacent New Mexico, and in the Big Bend area of Texas. These two populations are not closely connected in Mexico, and they differ in a number of ways, including egg color, bill color of the young, voice, and aspects of nesting behavior. The nesting habits in Arizona are surprisingly complicated, various members of the flock being more or less involved with several nesting attempts at once.
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
Crows, Magpies, Jays, Perching Birds
IUCN Status
Least Concern
Habitat
Arroyos and Canyons, Forests and Woodlands
Region
Southwest, Texas
Behavior
Flap/Glide, Undulating
Population
430.000
Range & Identification
Migration & Range Maps
Almost never moves away from immediate breeding territory; one of the most sedentary bird species in North America.
Description
11 1/2 -13" (29-33 cm). Plain dull blue above, smooth gray below. Juveniles in Arizona and New Mexico have pale bills at first, gradually becoming blackish. More heavily built than Woodhouse's Scrub-Jay, and lacks contrasting white throat and dark necklace.
Size
About the size of a Crow, About the size of a Robin
Color
Black, Blue, Gray, Yellow
Wing Shape
Broad, Long, Rounded
Tail Shape
Long, Rounded, Wedge-shaped
Songs and Calls
A loud shrink? or wenk? often repeated.
Call Pattern
Flat, Rising, Simple
Habitat
Open oak forests (Arizona); oak-pine woods (Texas). In Arizona, found in various oak woodlands, including those mixed with pines, in canyons and lower slopes of mountains (up to about 7,000'). Elsewhere in range, in Texas and Mexico, found in a variety of forests dominated by pines and oaks.
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Behavior
Eggs
4-5, sometimes 1-6. Eggs pale unmarked green in Arizona; in Texas, pale blue-green, usually with pale brownish spots. Incubation is by female only, about 18 days. Other adults in flock feed incubating female on nest.
Young
Fed by both parents and by other members of flock. Young leave nest at about 25-28 days, may be fed for several weeks thereafter.
Feeding Behavior
Forages on the ground or in trees, usually in flocks. May visit large flowers in summer for nectar and insects. Rarely catches insects in flight. Breaks open acorns by holding them against branch with feet and pounding with bill. Harvests acorns in fall and buries them in ground, often remembering location and retrieving them later.
Diet
Omnivorous; mostly acorns, seeds, insects. Diet is largely acorns and seeds of pinyon pine from fall through winter, mostly insects in summer. Eats grasshoppers, beetles, caterpillars, and many other insects; also lizards, small snakes, birds' eggs, rarely mice or birds.
Nesting
Flocks defend permanent territories that may remain the same for generations. Within each flock, 2-4 females may nest at one time; each is attended by one male, but may mate with other males in flock as well. In Texas, where flocks are smaller, may nest as isolated pairs. Nest site is in tree, often oak, juniper, or pine, usually well hidden among foliage. Height averages about 20' up, can be 6-60' above the ground. Nest (built by both sexes) is bulky cup of sticks and twigs, lined with fine rootlets and plant fibers.
Climate Vulnerability
Conservation Status
Still locally common in its limited U.S. range, with no obvious population trends.
Climate Threats Facing the Mexican Jay
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.