Pacific salmon (genus Oncorhynchus) spawning runs are
highly predictable in both space and time (e.g., Wood and
Foote 1996). These runs result in the transfer of significant
amounts of marine-derived nutrients to unproductive freshwater
systems (e.g., Bilby et al. 1996). Temporally and spatially
predictable resources are important in animal migrations
on both local and broad geographic scales, with salmonids
representing the positive extreme in predicability as a food
resource for other animals (Willson and Halupka 1995). However,
few studies have actually examined in detail the ecological
relationship between salmonids and those species that
exploit them