In Alaska, found in tidal sloughs, saltwater inlets and beaches, lower reaches of salmon spawning streams, shallow lakes, freshwater ponds and marshes. Nests in upperparts of trees and more rarely in shrubs or on ground. Nests in areas devoid of predators. Nests colonially in tall Sitka spruce, western red cedar, western hemlock, pine, red alder and black cottonwood (Campbell et al. 1990). Isolation from disturbance appears to be an important factor in nest site selection (Werschkul et al. 1976, Henny and Kurtz 1978, Parker 1980). Foraging habitat includes aquatic areas generally less than 0.5 m deep, such as: marine intertidal areas, estuaries, riparian areas, wetlands, freshwater lakes, and muskegs (Gabrielson and Lincoln 1959, Willard 1977). These areas are generally within 5 km of the nest site, although some areas have been identified up to 33 km (Mathisen and Richard 1978, Parris and Grau 1979, Thompson 1979). Considered adaptable. In winter and fall flies to estuaries and nearby grasslands or along riverbanks in BC.
Campbell, R. W., N. K. Dawe, I. McTaggart-Cowan, J. M. Cooper, G. W. Kaiser, and M. C. E. McNall. 1990. The Birds of British Columbia. Vol. 1 and 2, Nonpasserines. UBC Press, Vancouver, B.C.
￼￼￼Gabrielson, I. N. and F. C. Lincoln. 1959. The Birds of Alaska. The Stackpole Company, Harrisburg, PA and Wildl. Manage. Inst., Washington, D.C. 922 pp.
Henny, C.J. and J.E. Kurtz. 1978. Great blue herons respond to nesting and habitat loss. Wildl. Soc. Bull. 6:35-37.
￼￼￼Mathisen, J. and A. Richards. 1978. Status of great blue herons on the Chippewa National Forest. Loon 50:104-106.
Parker, J. 1980. Great blue herons (Ardea herodia) in northwestern Montana: nesting habitat use and the effects of human disturbance. M.S. Thesis, Univ. of Montana. 82 p.
Parris, R.W. and G.A. Grau. 1979. Feeding sites of great blue herons in southwestern Lake Erie. Proceedings Colonial Waterbird Group 2:110-113.
Thompson, D.H. 1979. Feeding areas of great blue herons and great egrets nesting within the floodplain of the upper Mississippi River. Proceedings of Colonial Waterbird Group. 2:202-213.
Werschkul, D.F., E. McMahon, and M. Leitschuh. 1976. Some effects of human activities on the great blue heron in Oregon. Wilson Bull. 88(4):660-662.
￼￼￼Willard, D.E. 1977. The feeding ecology and behavior of five species of herons in southeastern New Jersey. Condor 79:462-470.