Ydenberg, Ronald C.

I studied nesting habitat selection and fledging success by marbled murrelets, a seabird that nests in old-growth forests of high economic value, at two regions of southwestern British Columbia. At Clayoquot Sound, habitat occurs in larger stands, and murrelets selected steeper slopes and patches with more platform trees, and shorter trees, than at random sites. At Desolation Sound, where smaller forest stands predominate, patch scale variables were less important; increased canopy complexity in the patch, and wetter/cooler landscape aspects distinguished nests from random sites. In both regions, nests were often in “distinctive” trees, taller and with more potential platforms than others in the patch. Habitat features at multiple scales did not predict fledging success. Habitat quality as ranked by current remote methods (air photo interpretation, low-level aerial surveys) correlates with probability of use derived from stand-level habitat selection models, providing a quantitative assessment of their effectiveness as management tools.