These data were compiled to explore the foraging ecology of Rainbow Trout (Oncorhynchus mykiss) in the Colorado River, Grand Canyon, Arizona. These data represent samples characterizing the availability of drifting invertebrate prey (hereafter, drift) and use of these invertebrate prey by rainbow tr

Colorado Division of Wildlife and US Fish and Wildlife Service. April 2005.

We present four lines of evidence that the magnitude of prey exchange (=immigration/emigration) among substrate patches has an overwhelming influence on the perceived effects of predators on prey populations. (1) An extensive review of the literature on predation effects in benthic and littoral fres

This study is the first to document the use of hydrodynamic cues by stream-dwelling predators for discrimination of prey from nonprey and provides a mechanism to explain selective predation by stoneflies on Baetis in nature.

Behavior of Baetis bicaudatus (Ephemeroptera; Baetidae) was video taped in a western Colorado, USA stream to identify the specific stimuli eliciting noncontact responses to predatory stoneflies (Kogotus modestus; Plecoptera; Perlodidae). In situ behavioral and feeding trial experiments were also con

Abstract: To investigate possible biological effects of acidic deposition in the western United States, we performed population censuses and dose‐response experiments at a subalpine watershed in the Rocky Mountains of Colorado, An adult tiger salamander (Ambystoma tigrinum nebulosum) population decl

Investigation of this mating system in Epeerus longimanus, a mayfly of the western United States that forms swarms that are quite large, finds that swarm locations are not explainable as feeding or emergence sites, but they do correlate with landscape features.

We determined the distance travelled by drifting nymphs of the mayflies Baetis and Cinygmula to add to existing knowledge of factors influencing drift distance, and to investigate the influence of drift-exiting behavior upon drift magnitude and periodicity. Individuals were released into the water c

Five species of stoneflies (Zapada haysi, Plumiperla diversa, Taenionema pacificum, Isoperla petersoni, Arcynopteryx compacta) from the North Slope and Interior of Alaska were examined for seasonal patterns of emergence of adults and growth of nymphs. Generally growth was retarded during the winter

At least 20 species of Trichomycetes (Zygomycotina) were dissected from the hindguts and peritrophic membranes of larval Diptera (Simuliidae, Chironomidae), Ephemeroptera, and Plecoptera in two high-altitude streams, and the trichomycete species diversity in the two streams was compared. Periodic sa

Values increased with increasing size of the predator, and inclusion of the C/A term indicated that predators would obtain greater reward from small relative to large prey, and from dipterans relative to mayflies.