Medium-sized, dull grayish brown wren (length 12.5 to 15 cm; mass 15 to 18 g). Adult has grayish-brown upperparts finely speckled with white and black, with contrasting cinnamon rump; tail brown above with black bars. Underparts dull white finely streaked gray on throat and breast. Sexes alike in all plumages. Distinguished from most other wrens by combination of medium size with relatively long tail, paler coloration finely speckled above with black and white markings, noticeable black subterminal bar on tail, and bobbing habit and cheery, distinctive call (Lowther et al. 2000).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
Western Hemisphere Range
eBird Occurrence Map
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In the Bozeman area, normal migration periods are May 8 to 25 and August 25 to September 7.
The Rock Wren is well named. Most descriptions of Rock Wren habitat mention "rock" for this pale wren of arid, western North America. Still, these wrens are also found in nonrocky habitats, as long as there exists areas "rich in crevices, interstices, passageways, recesses, and nooks and crannies of diverse shapes and sizes" (Ryser 1985, Lowther et al. 2000).
Insects and other arthropods (Lowther et al. 2000).
Nest in cavity or crevice in or among rocks. Eggs usually ovate in shape. Pure, glossy white with fine spots of reddish brown. Clutch size commonly 5 to 6, as few as 4, and as many as 10 (Lowther et al. 2000). From Wyoming to Alberta, egg records are from May 27 to July 15, and nestling records from June to July 23.