Declines in Greater Sage-Grouse (Centrocercus urophasianus, hereafter sage-grouse) populations could be attributed to low chick survival, which may be influenced by the availability of food and cover at sites used by females rearing broods. Habitat attributes important to broods may vary regionally; thus, it is necessary to understand factors affecting...
A fully illustrated key is presented for identifying genera of oribatid mites known from or suspected of occurring in the Pacific Northwest. The manual includes an introduction detailing sampling methodology; an illustrated glossary of all terminology used; two color plates of all taxa from the H.J. Andrews Experimental Forest; a...
Strongly bimodal, basalt-rhyolite volcanism of the High Lava Plains Province of Oregon followed the Middle Miocene flood basalts of the Pacific Northwest and extends to recent time. During the 8 m.y. of volcanism recorded in the central High Lava Plains, in western Harney Basin, three distinct mafic magmatic trends originate...
It is unlikely all male sage-grouse are detected during lek counts, which could complicate the use of lek counts as an index to population abundance. Understanding factors that influence detection probabilities will allow managers to more accurately estimate the number of males present on leks. We fitted 410 males with...
The Columbia River seal control program operated under legislative authority. The Fish Commission paid has paid a bounty since 1936 and hired a seal hunter during 1958-1970. In May 1972, the author wrote to resource management and research agencies in 18 seaboard states, Canada, and Scotland to seek suggestions for...
Various mollusks, including small bivalves and gastropod snails, are a common food source for intertidal crabs. Prey opening techniques used on hard-shell prey are dependent on claw size and morphology. For example, large, strong claws can crush a snail outright while smaller, weaker claws leave characteristic peels, pulls and upper...
This report provides a strategic approach developed by a Western Association of Fish and Wildlife Agencies interagency working group for conservation of sagebrush ecosystems, Greater sage-grouse, and Gunnison sage-grouse. It uses information on (1) factors that influence sagebrush ecosystem resilience to disturbance and resistance to nonnative invasive annual grasses and...
Oceanographic data collected in the Umpqua River Estuary, Oregon, during the period April 26-27, 1961, are tabulated. Temperature, salinity, velocity, and dissolved oxygen were observed at various depths over one tidal cycle at a mid-channel anchor station located near the mouth of the river.