Publications

Nesting success was studied at Canvasback Lake and Mallard Lake on the Yukon Flats in interior Alaska in 1989–1991. Simple estimates of nesting success were computed using two techniques that assume a constant daily survival rate (DSR). Maximum-likelihood estimates of nesting success for all ducks, assuming constant DSR, ranged among years and sites from near zero to 12%. However, DSRs...

Juvenile coho salmon (Oncorhynchus kisutch) from three populations in Washington State were captured in the field and tested for critical thermal maximum (CTM). Tolerances varied among the populations (mean CTMs were 28.21, 29.13, and 29.23 °C) and exceeded published data from some laboratory tests. The population from a relatively cool stream had a lower CTM than the two populations...

Using satellite telemetry, we monitored the movements of an adult female polar bear (Ursus maritimus) as she traveled from the Alaskan Beaufort Sea coast to northern Greenland. She is the first polar bear known to depart the Beaufort Sea region for an extended period, and the first polar bear known to move between Alaska and Greenland. This bear traveled for four months across the polar...

The March-April issue of American Scientist contains a commentary by Julia K. Parrish and P. Dee Boersma (Macroscope, "Muddy Waters") that purports to "assess the validity of the claims made concerning seabird mortality as a result of the [Exxon Valdez oil] spill." Parrish and Boersma would have us believe that estimates of seabird mortality made in 1990 by myself and colleagues were...

No abstract available.

We modified standard aerial survey data collection to obtain the geographic location for each waterfowl observation on surveys in Alaska during 1987-1993. Using transect navigation with CPS (global positioning system), data recording on continuously running tapes, and a computer data input program, we located observations with an average deviation along transects of 214 m. The method...

Morphological, behavioral, and life-history differences between Pacific salmon (Oncorhynchus spp.) populations are commonly thought to reflect local adaptation, and it is likewise common to assume that salmon populations separated by small distances are locally adapted. Two alternatives to local adaptation exist: random genetic differentiation owing to genetic drift and founder events...

Black bear damage to 108 lodgepole pine trees was found in mixed conifer habitat in central Oregon. No trees of three other conifer species were injured. Eighty-nine percent of the damage occurred in the same year. Nearly 20% of the freshly damaged trees had bark removed from more than 75% of the circumference and, judging from the fate of trees damaged in prior years, probably

The effects of vegetation management on Mazama pocket gopher activity and damage to ponderosa pine seedlings were studied using atrazine herbicide to alter the habitat. Atrazine treatments were applied to a large treatment unit and observed effects were compared to an untreated control unit. The greatly reduced forb and grass cover on the treated unit was associated with a corresponding...

We mounted a video camcorder in a single-engine aircraft to estimate nesting density along 10-m wide strip transects in black brant colonies on the Yukon Delta National Wildlife Refuge, Alaska during 1990-1992. A global positioning system (GPS) receiver was connected to the video recorder and a laptop computer to locate transects and annotate video tape with time and latitude

Polar bears are hunted throughout most of their range. In addition to hunting, polar bears of the Beaufort Sea region are exposed to mineral and hydrocarbon extraction and related human activities such as shipping, road building, and seismic testing. As human populations increase and demands for polar bears and other arctic resources escalate, reliable estimates of survivorship

Some aspects of a previously described migratory paradigm for the southern form of anadromous Dolly Varden Salvelinus malma were investigated with seven 3‐year mark–recapture experiments on fish that used lakes in eight watersheds as their winter residence. Weirs on Kodiak Island, around Prince William Sound, and near Juneau, Alaska, were used to capture Dolly Varden as they emigrated to...