Twenty-eight Columbia ewes were made available for study
during their breeding and anestrous seasons. After the regularity
of the estrous cycles had been established, eight of the ewes were
sacrificed in pairs at four different stages of the estrous cycle.
Eight additional ewes were sacrificed during anestrus. Pituitary
glands, ovaries,...
Steelhead and rainbow trout are common names for marine-migratory (anadromous) and freshwater-resident forms of Oncorhynchus mykiss, a partially migratory salmonid fish. Anadromous and resident forms are sympatric and can produce offspring with a life history different from their own (i.e., steelhead parents can produce rainbow trout offspring and vice versa)....
The evolution and maintenance of multiple phenotypes within populations is an interesting evolutionary and ecological question, and is becoming increasingly important for the restoration and conservation of partially migratory species. In particular, why individuals adopt a particular phenotype has been the focus of numerous research efforts. In the partially migratory...
Partial migration is a common migratory behavior where some individuals in a population migrate and others do not. Patterns of partial migration can vary dramatically, especially for species that inhabit a wide range of environments. I described and predicted spatial variation in marine migration (anadromy) of female Oncorhynchus mykiss (steelhead...
Alternative male phenotypes in salmonine fishes arise from individuals that mature as either larger and older anadromous marine-migrants or as smaller and younger freshwater residents. Variability in age and size of males at maturity is hypothesized to be preceded by early differences in growth in size and lipid storage. Water...
The Confucius Institutes program is a Chinese organization established in 2004 to provide the world with language instruction and increase cultural awareness. The program forms joint venture business models with universities and schools around the world to establish language and culture centers on their school’s campus (“Constitution and By-Laws”). Over...
1. Aquatic ecologists are working to develop theory and techniques for analysis of dynamic stream processes and communities of organisms. Such work is critical for the development of conservation plans that are relevant at the scale of entire ecosystems. The stream network is the foundation upon which stream systems are...
This study uses multiple regression analysis of a survey of Oregon residents to determine what factors influence an individual’s support for salmon recovery policies in Oregon. Salmon today face a variety of threats, most notably from the ‘four H’s’ (habitat degradation, hydroelectric dams, harvest practices, and hatcheries). Using the social...
A study was conducted of the response of the garden symphylan,
Scutigerella immaculata (Newport), to naturally occurring chemicals.
Results of olfactometer studies with plant odors were inconclusive
because air currents in one olfactometer and the shape of another had
undesirable effects on symphylan behavior.
Non-random distributions of symphylans in chambers...