8100

• UCREFRP Catalog Number: 8100
• Author: American Fisheries Society.
• Title: Proceedings of the 22nd Annual Meeting, Colorado - Wyoming Chapter, American Fisheries Society.
• USFW Year: 1987.
• USFW - Doc Type: March 11-12, 1987.
• Copyright Material: NO

FOOD SELECTION BY BROOK TROUT IN A SUBALPINE STREAM
WAYNE A. HUBERT
WYOMING COOPERATIVE FISH AND WILDLIFE RESEARCH UNIT
UNIVERSITY OF WYOMING
LARAMIE, WYOMING 82071
HOWARD A. RHODES
5526 PILOT PEAK ROAD
LARAMIE, WYOMING 82070

ABSTRACT

Brook trout (Salvelinus fontinalis) diet, macroinvertebrate drift
and food selection by brook trout were described in a high altitude
(3,205 m above mean sea level) stream on the Snowy Range in the
Medicine Bow National Forest, Wyoming. Diet composition was observed
to be different between two size classes of brook trout, ~ 150 mm total
length and> 150 mm. Variation in the number of prey organisms/stomach
and diet composition occurred over the July to September, 1985 sampling
interval. There was a general decl ine in the number of prey/stomach
and an increase in the proportion of terrestrial prey items between
Jul y and September. Se 1 ect i on for Tri choptera and Coleoptera was
observed for both size classes of fish over the three sampling months,
while selection for terrestrial insects by fish> 150 mm was also
observed in August and September.

INTRODUCTION

~

Despite the wide array of work on brook trout (Salvelinus fontinalis)
ecology, few researchers have studied the diet of brook trout in high-elevation
streams of the Central Rocky Mountains where brook trout are often the
predominant or sole salmonid species. Allan (1987, 1981) described brook trout
diet and prey selection in a meadow reach of Cement Creek (3,100 m above mean sea
level), a small stream in Gunnison County, Colorado. Reed and Bear (1966)
described the benthos and foods eaten by brook trout in a valley stream at 2,900
m in elevation near Gunnison, Colorado. Wiseman (1951) assessed the diet of
brook trout in the Medicine Bow Mountains at lower elevation sites than used in
our study. Griffith (1974) described the diet and prey selection of allopatric
and sympatric populations of brook trout in mountain streams in Idaho.

The purpose of our study was to describe the diet of brook trout, as well as

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