Typically breeds near treeline. Open shrubby areas of willow, birch, alder, stunted spruce and open tundra with scattered shrubs common breeding habitat. Small trees used as singing posts. Often near water, such as lakes or bogs (Naugler 1993). In B. C., nests in elevations between 800 and 1,400 m. Nesting habitat is near the altitudinal limit of trees, where subalpine meadows and wet or marshy wetlands are interspersed with willow thickets from a few centimeters to 2 m or more. Spruce, subalpine fir, and scrub birch are often present (Campbell et al. 2001).
Campbell, R. W., N. K. Dawe, I. McTaggart-Cowan, J. M. Cooper, G. W. Kaiser, A. C. Stewart, and M. C. E. McNall. 2001. The Birds of British Columbia. Volume 4. Passerines: wood-warblers through Old World sparrows. University of British Columbia Press, Vancouver. 739 pages.
Naugler, C. T. 1993. American Tree Sparrow (Spizella arborea). In The Birds of North America, Vol. 7, No. 37 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union.