Nest Site Selection by Reticulate Sculpin in Two Streams of Different Geologies in the Central Coast Range of Oregon

Abstract

Nest sites of reticulate sculpin Cottus perplexus were located in segments of two streams that were similar in gradient, basin area, elevation, climate, and riparian vegetation but that differed in geology and biological community structure. An electivity index was used to determine habitat selected for nest sites. Strong positive selection for moderately embedded cobble substrate was shown in pools and riffles from both stream segments, even though the availability of that habitat varied. No eggs were found attached to bedrock, wood, or particles smaller than large gravel. Only 1 of the 471 nests located was associated with rocks that were embedded more than 50%.