Stream Size Mediates the Ecological Effects of Bear Predation on Salmon

Abstract

Quinn will describe a study of salmon predation by bears in Alaska. The study looked at the controls on the number and proportion of salmon killed in a creek each year. Quinn will outline the observed patterns: 1. Bears kill a higher proportion of the salmon in narrow than wide streams. 2.The number of salmon killed reaches an asymptote at high salmon density. 3. Bears consume body parts to maximize energy density, not volume. 4. Bears are most selective when salmon are most available. Quinn will also discuss carcass deposition and the nutrient flow, via terrestrial and aquatic pathways. He will conclude that stream size plays a key direct and indirect role in the ecology of salmon and bears.