Use of fragmented landscapes by marbled murrelets for nesting in southern Oregon

作者：Meyer CB^*; Miller SL

来源：Conservation Biology, 2002, 16(3): 755-766.

DOI：10.1046/j.1523-1739.2002.00004.x

As old-growth forest becomes more fragmented in the Pacific Northwest (U.S.A.), species dependent on large patches of old-growth forest may be at greater risk of extinction. The Marbled Murrelet (Brachyramphus marmoratus ), a seabird whose populations are declining in North America, nests in such old-growth forests or forests with large remnant trees. Using logistic regression models on landscapes in southern Oregon, we addressed (1) whether old-growth forest fragmentation was associated with use of an area by murrelets and (2) whether proximity to certain marine features was associated with use of forest fragments by murrelets. On a geographic information system vegetation map derived from satellite imagery, we placed circular plots of 400-, 800-, 1600-, and 3200-m radius over surveyed inland areas occupied or unoccupied by murrelets. Within each plot, spatial and other land- and seascape habitat variables were calculated and regressed against murrelet occupancy. Murrelets generally occupied low-elevation inland sites in landscapes with relatively low fragmentation and isolation of old-growth forest patches, and these sites were close to the coast, river mouths, and a major bay. Almost all occupied landscapes occurred in a fog-influenced vegetation zone. Because nesting habitat with large amounts of interior forest is currently scarce in southern Oregon, management efforts should focus on protecting or creating large, contiguous blocks of old-growth forest, especially in areas near the coast.

• 出版日期2002-6