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Abstract
Most Marbled Murrelets (
Brachyramphus marmoratus) in British Columbia nest in the Coastal Western Hemlock biogeoclimatic zone. In this zone, detection frequencies were highest in the moister ecosections and in low elevation forests. Nests and moderately high levels of activity were also found in some forest patches in the subalpine Mountain Hemlock zone. There was no evidence of nesting in subalpine scrub forest, lowland bog forest, or alpine tundra. Studies on the Queen Charlotte Islands and Vancouver Island reported consistently higher detection frequencies in old-growth than second growth forests (20-120 years old). Detections in second-growth were usually associated with nearby patches of old-growth. Within low elevation old-growth, detection frequencies were sometimes positively correlated with mean tree diameter, but showed weak or no associations with tree species composition and minor variations in forest structure. Sitka spruce (
Picea sitchensis) and western hemlock (
Tsuga heterophylla) were important components of many high-activity sites. High murrelet activities were associated with well-developed epiphytic mosses, but mistletoe seemed less important. A study on Vancouver Island showed higher predation of artificial nests and eggs at forest edges, which suggests problems for Marbled Murrelets in fragmented forests. The use of detection frequencies in the selection and preservation of potential nesting habitat is discussed and the limitations of single-year studies are exposed.
Parent Publication
Citation
Burger, Alan E. 1995. Chapter 16: Inland Habitat Associations of Marbled Murrelets in British Columbia. In: Ralph, C. John; Hunt, George L., Jr.; Raphael, Martin G.; Piatt, John F., Technical Editors. 1995. Ecology and conservation of the Marbled Murrelet. Gen. Tech. Rep. PSW-GTR-152. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; p. 151-162
