학술논문
Bioenergetics-based predator-prey relationships between piscivorous birds and juvenile salmonids in the Columbia River estuary.
Document Type
Theses
Author
Source
Dissertation Abstracts International; Dissertation Abstract International; 71-10B.
Subject
Language
English
Abstract
Summary: Climate was an important factor modulating Caspian tern predation on salmonids, with greater consumption of smolts occurring in years of cooler ocean conditions and higher Columbia River flows. Climate did not contribute to variation in consumption of salmonids by cormorants, perhaps due to the larger effect of growth in the size of the cormorant colony during the study period. Due to current trends in colony size (terns: stable, cormorants: increasing) and the planned dispersal of a portion of the tern population, cormorant predation will likely be a more significant mortality factor for Columbia Basin salmonids in the future than will tern predation. A critical unknown factor remains; that is the degree to which reductions in avian predation on salmonids might be compensated for by other salmonid mortality factors.