Publications

We documented 12 sites in the Yellowstone ecosystem where grizzly bears (Ursus arctos horribilis) had purposefully consumed soil (an activity known as geophagy). We also documented soil in numerous grizzly bear feces. Geophagy primarily occurred at sites barren of vegetation where surficial geology had been modified by geothermal activity. There was no evidence of ungulate use at most...

We reviewed cases of raptor mortality resulting from cholinesterase-inhibiting pesticides. We compiled records from the U.S., U.K. and Canada for the period 1985-95 (520 incidents) and surveyed the relevant literature to identify the main routes of exposure and those products that led to the greatest number of poisoning cases. A high proportion of cases in the U.K. resulted from abusive...

A team of fire scientists and resource managers convened 17-19 April 1996 in Seattle, Washington, to assess the effects of fire disturbance on ecosystems. Objectives of this workshop were to develop scientific recommendations for future fire research and management activities. These recommendations included a series of numerically ranked scientific and managerial questions and responses...

Lack of information concerning predatory interactions between Ambystoma gracile and Ambystoma macrodactylum (long-toed salamander) larvae, as well as potential cannibalism within A. gracile populations, prompted us to conduct a field experiment to investigate the potential for this inter- and intraspecific predation. This field experiment was conducted at a lake in Mount Rainier National...

The American Kestrel(Falco sparverius) is a sexually dichromatic falcon that exhibits considerable individual plumage variability. For example, the anterior extent of the black dorsal barring in juvenile males has been used throughout North America as one of several aging criteria, but recent data demonstrate that the variability among individual Southeastern American Kestrels(E S...

A synoptic inventory of physical and chemical properties and plankton assemblages of 27 mountain lakes was conducted at Mount Rainier National Park in 1988. From 1990–1993, die opportunity was presented to resurvey six of these lakes to determine inter-annual change within die set of characteristics surveyed in 1988. If changes were evident, a second objective was to provide guidance to...

Connectivity of discrete habitat patches may be described in terms of the movements of individual organisms among such patches. To examine connectivity of widely dispersed alkali lake systems, we recorded post-breeding and subsequent breeding locations of color-banded American Avocets (Recurvirostra americana) in the western U.S. Great Basin, from 1995-1997. Among individuals observed...

Butyltin compounds, including mono-, di-, and tributyltin (MBT, DBT, and TBT) were measured in livers of 40 adult river otters (Lutra canadensis) collected from rivers and coastal bays in Washington and Oregon, USA. Butyltins were found in all the river otters, at a concentration range of 8.5–2,610 ng/g, WW. The greatest concentration of total butyltins of 2,610 ng/g, WW, was found in a...

Tree-ring chronologies for mountain hemlock (Tsuga mertensiana) were used to reconstruct the water level of Crater Lake, a high-elevation lake in the southern Cascade Range of Oregon. Reconstructions indicate that lake level since the late 1980s has been lower than at any point in the last 300 years except the early 1930s to mid 1940s. Lake level was consistently higher during the Little...

We investigated chlorinated hydrocarbon contaminants in aquatic mustelid species on the Fraser and Columbia Rivers of northwestern North America. Carcasses of river otter (Lutra canadensis) (N=24) and mink (Mustela vison) (N=34) were obtained from commercial trappers during the winters of 1990–91 and 1991–92. Pooled liver samples were analyzed for organochlorine pesticides...

Tailed frogs (Ascaphus truei) occur in permanent, cold streams in northwestern North America. Their tadpoles reportedly undergo metamorphosis after 2-4 years. Coastal populations that we examined transformed in 2 yr from the Olympic peninsula in Washington to northern Oregon, but in 1 yr from central Oregon to northern California. One inland site in northern California had a 2-yr period...

In July 1981, 5 adult rhinoceros auklets (Cerorhinca monocerata) were captured on the ground near nesting areas on each of Protection and Destruction Islands, Washington. The birds were euthanized, and their livers and kidneys removed and analyzed. Levels (I?g / g wet weight) of DDE (0.11 to 0.95), polychlorinated biphenyls (no residue detected [ND] to 1.1), mercury (0.60 to 1.8), and...