Instream cover and shade mediate avian predation on trout in semi-natural streams

Abstract

Piscivory by birds can be important, particularly on fish in small streams and during seasonal low flows when available cover from predators can be limited. We conducted an experiment at the Oregon Hatchery Research Center to evaluate size-selective survival of Coastal Cutthroat Trout (Figure 8; Oncorhynchus clarkii clarkii) in replicated semi-natural stream sections. Our findings, published in the Ecology of Freshwater Fish highlights that availability of instream cover and overhead shade from riparian vegetation can increase trout survival by reducing the effect of predation by Belted Kingfishers Megaceryle alcyon and potentially other avian predators (Figure 9).

Citation

Penaluna, Brooke E.; Noakes, David L. G. 2015. Instream cover and shade mediate avian predation on trout in semi-natural streams. StreamNotes: The technical newsletter of the national stream and aquatic ecology center. August: 9-10.