Pronghorn (Antilocapra americana) use of four playas (intermittent lakebeds) on Hart Mountain National Antelope Refuge (NAR) in south central Oregon was studied during the summers of 1974 and
1975. Percent canopy cover of playa vegetation, plant phenology, percent desiccated vegetation, soil moisture, available surface water and pronghorn use of range...
The nature of the interaction between juvenile coho salmon, Oncorhynchus kisutch (Walbaum), and fall chinook salmon, 0. tshawytscha (Walbaum), was studied in Sixes River, Oregon. Seining, snorkeling, and tagging were used to determine distribution and patterns of growth of these two species in the stream environment. Experiments conducted in flowing-water...
The ³²P material balance method for measuring periphyton production and grazing rates on periphyton in streams developed by Elwood and Nelson (1972) was evaluated by laboratory and field experiments. Three basic assumptions of the method were examined: 1) sloughing of periphyton from substrates is negligible, 2) sorption of ³²P onto...
The hypotheses to be tested in this investigation are: 1) there is a threshold level of liver lipid and glycogen content above which the health condition of hatchery-reared fish is impaired, 2) fatty and high glycogen livers impair liver function and structure, and 3) fatty and high glycogen livers increase...
The genotype frequencies of one-year-old oyster spat
(Crassostrea gigas) from parents of known genotype, are compared
to the frequencies expected with Mendelian inheritance. The genotypes
are characterized at three enzyme loci, Aspartate amino-transferase
(AAT), Phosphohexose isomerase (PHI) and Leucine
aminopeptidase (LAP), and a general protein locus. In this study
expression...
The rainbow trout population in Elder Creek, Oregon was
studied between June 1965 and November 1966. The physical characteristics
of the stream during the summer season were described.
Rainbow trout were captured in each of three sections on the stream
by electrofishing and were tagged and measured. Population size,
mortality,...
The desire to understand the spatial and temporal drivers of animal behavior and distribution relative to scale is central to movement ecology. Optimal foraging theory states that a predator should continue exploiting a patch until it is no longer profitable to do so. As human developments increasingly encroach on the...