I experimentally test the hypothesis that the potential for selfing
increases with plant size in Mertensia ciliata (Boraginaceae), a self-compatible,
profusely-flowering perennial. This follows from the
premises that 1) pollen dispersal by pollinators between flowers is
limited, and 2) individual pollinators, in this study bumblebees, will
visit more flowers per...
To assess the context dependence of kin discriminating
behavior, I examined kin-biased aggregation behavior in tadpoles
of R. cascadae in different ecological conditions. I manipulated food
distribution, predator presence, thermal heterogeneity, and
relatedness in a multifactorial mesocosm experiment. All four
factors interacted to influence tadpole dispersion. My results
suggest that...
Identifying appropriate units for conservation requires knowledge of evolutionary
patterns and risks of managing at different geographical and genetic scales. I examined
genetic diversity at different geographical scales among 11,400 rainbow trout
(Oncorhynchus mykiss) from 243 locations in 13 major river basins throughout much of
their range and among coho...
During the years between 1930 and 1950 a number of attempts
were made to introduce techniques and ideas from cytology,
ecology, and genetics into the field of taxonomy. Advocates of
this "experimental taxonomy" believed that cytological, ecological,
and genetic techniques would provide a rigorous, objective
methodology to replace the traditional...
Habitat selection behavior was investigated as a proximate mechanism influencing spatial distributions of three species of anuran larvae. Rana cascadae, Hyla regilla, and Bufo boreas overlap in distribution in lakes and ponds of the Cascade Mts. and were chosen to provide a comparative basis for analyzing habitat selection behavior. Major...
I tested a theoretical model proposing that anemia
favors transmission of blood-borne parasites to vectors
by accelerating the blood-feeding rate. Using Aedes
aegypti, the yellow fever mosquito, initially, I was not
able to confirm this phenomenon either in an artificial
or a live system; anemia did not correlate with blood-feeding...
Effects of the marine environment on age and size at maturity, early marine growth, and abundance of chum salmon, Oncorhynchus keta, were studied at Olsen Creek during 1959-77. Chum salmon returned to Olsen Creek as predominately 3-, 4-, and 5-year fish; however, age composition varied from year to year. The...