This is our largest Myiarchus. The western subspecies dwarfs the smaller dusky-capped; the eastern subspecies is closer in size to the great crested and the ash-throated. Brown-cresteds prefer more mature, undisturbed habitats where larger nest cavities are available. Polytypic (7 ssp.; 2 in North America). Length 7.2–9.2".
Adult: gray and yellow areas of underparts fairly bright, with abrupt gray-yellow contrast on breast. Outer pairs of tail feathers extensively rufous on inner webs; dark shaft stripes and rufous extend to feather tips. Bill proportionately long, heavy, and black. Mouth lining typically flesh-colored. Juvenile: similar, but secondaries (except whitish inner 2) and wing bars are rusty edged and inner webs of tail feathers are more extensively rufous (dark shaft stripe mostly lacking).
Larger magister breeds in Southwest south through western Mexico; smaller cooperi breeds in southern Texas and eastern Mexico south to Honduras.
The great crested has a darker gray face and breast; olive wash on sides of breast; broad white edge to innermost secondary; all-rufous inner webs of tail feathers; orange-yellow mouth lining; and paler base to lower mandible. The smaller, paler ash-throated has whitish transition between gray and yellow on underparts, and its tail tip is usually dark not rufous. The smaller Nutting’s and dusky-capped have orange mouth lining; the dusky-capped has much less rufous in tail.
Call: a sharp whit. Breeding, a rough, descending burrrk (or rasp) or whay-burg. Dawn song: repeated whit notes, vibrato whistles, burrrk notes, and other complex phrases.
Status and Distribution
Common. Breeding: riparian forest, thorn woodland, columnar cactus desert. Migration: in spring, arrives in Texas exceptionally by mid- to late March, more typically early to mid-April; arrives in Southwest late April–early May. In fall, generally departs August, rare after mid-September. Winter: mexico to Honduras. Vagrant: casual, mainly fall-winter, to coastal Califorinia (magister) and to coastal Texas, Louisiana, and Florida (cooperi, but 1 Louisiana rec. of magister).
—From the National Geographic book Complete Birds of North America, 2006