Description of Two Marbled Murrelet Tree Nests in the Walbran Valley, British Columbia

Abstract

We discovered 2 marbled murrelet (Brachyramphus marmoratus) tree nests in West Walbran Valley on the west coast of Vancouver Island, British Columbia, by observing murrelet behavior during dawn surveys and climbing potential nest trees. Both nests were in old-growth Sitka spruce (Picea sitchensis) trees. They were unoccupied when found but each had distinct fecal rings and contained eggshell fragments, indicating that they had been used recently. These were the first marbled murrelet nests found in British Columbia and the first nests located in Sitka spruce trees within the murrelet's range in North America. Marbled murrelets (Brachyramphus marmoratus) are widely distributed in the nearshore waters of British Columbia (Campbell et al. 1990), with 45,000-50,000 breeding birds in the population (Rodway 1990, Rodway et al. 1992). Research before 1990 focused primarily on birds at sea (Sealy 1974, Carter 1984, Sealy and Carter 1984), few forest surveys had been conducted, and no marbled murrelet nests had been documented in the Province. Nesting evidence, derived from records of young discovered at inland locations and probable nests found during logging operations (Carter and Sealy 1987b, Campbell et al. 1990), indicated that murrelets likely nested in coastal old-growth forests in British Columbia. These forests are threatened by logging and development, especially on Vancouver Island. Because of these and other threats, the marbled murrelet was listed as threatened in British Columbia in 1990