Inhabits open areas, usually near water, including open fields, marshes, shorelines, and wooded swamps with standing dead trees (Robertson et al. 1992). Standing dead trees that offer nesting cavities are an important habitat component (Alexander et al. 2003). Nests in bird boxes and sometimes buildings (Armstrong 2008). Closely tied to human settlement in tundra areas (Armstrong 2008). Northern breeding limit generally treeline (Erskine 1977). In B.C., breeds from near sea level to 1,450 m elevation (Campbell et al. 1997).
Alexander, S. A., F. I. Doyle, C. D. Ecker, H. Grünberg, N. L. Hughes, M. Jensen, I. Johnson, D. H. Mossop, W. A. Nixon, and P. H. Sinclair. 2003. Birds of the Yukon Territory (P. H. Sinclair, W. A. Nixon, C. D. Eckert, and N. L. Hughes, eds.). UBC Press, Vancouver, B.C.
Armstrong, R. H. 2008. Guide to the birds of Alaska. 5th edition. Alaska Northwest Books, Anchorage, AK. 360 pp.
Campbell, R. W., N. K. Dawe, I. McTaggart-Cowan, J. M. Cooper, G. W. Kaiser, M. C. E. McNall, and G. E. J. Smith. 1997. The Birds of British Columbia. Volume 3. Passerines: flycatchers through vireos. University of British Columbia Press, Vancouver. 693 pages.
Erskine, A. J. 1977. Birds in boreal Canada. Report 41. Canadian Wildlife Service, Ottawa, Ontario.
Robertson, R. J., B. J. Stutchbury, and R. R. Cohen. 1992. Tree Shallow (Tachycineta bicolor). In The Birds of North America, No. 11 (A. Poole, P. Stettenheim, and F. Gill (Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union.