The ecology of female Great Basin Canada geese (Branta
canadensis moffitti) and their broods was studied during the rearing
seasons of 1983 and 1984 on the Columbia River in southcentral
Washington. The movements and activities of 41 adult female geese,
marked with radio-transmitters, and their broods were monitored.
Adult female...
During the past decade (1978-87), breeding success and
productivity of bald eagles on the lower Columbia River (LCR) has
been far below state and regional averages and well below levels
required for delisting under the Endangered Species Act by the
Pacific States Bald Eagle Recovery Plan. Human disturbance was
suspected...
I used program CAPTURE to analyze 1,535 data sets for 33 North American species of small mammals for sources of variation in capture probabilities and to characterize species-specific responses to markrecapture trapping. CAPTURE incorporates seven models to account for all possible combinations of heterogeneity (h), behavioral response (b), and time...
I compared species composition and relative abundance of'small
mammals and herpetofauna between riparian and upslope habitats among 5
forest types. Riparian- and upslope- associated species were identified
based on capture frequency. Small mammal species richness was similar
between stream and upslope habitats and among the 5 forest types. There
were...
No studies have evaluated the effects of limited vehicle access on movements, survival and habitat use of Roosevelt
elk (Cervus elaphus roosevelti) . We installed twenty gates, restricting motorized vehicle access by the public in
seven discrete Road Management Areas (RMAs), comprising 35% of the study area. We radio-tracked 31...
Large burrowing owl (Aihene cunicularia) populations exist in areas of intensive agriculture in California, and pesticide exposure has been identified as a potential threat to population persistence. I evaluated breeding season use of agricultural fields by adult male owls using radio telemetry, and examined egg contaminant residues to estimate population-level...
Evaporation ponds that dispose of agricultural drainwater provide attractive habitat for waterbirds but may result in contaminant exposure that impairs reproduction. I estimated post-hatching survival and evaluated productivity estimates for American avocets (Recurvirostra americana) nesting at evaporation ponds in the Tulare Basin, California from 1991 to 1993. Avocets and Black-necked...
Diets and foraging strategies of Glaucous-winged Gulls were
studied in areas with and without sea otters in the western Aleutian
Islands, Alaska. Gulls foraged on invertebrates (e.g., sea urchins,
limpets, chitons, mussels, and others) in the rocky intertidal
community and on fish at sea; this study was conducted on gulls...
Food habits and levels of organochlorine compounds, lead, and mercury in resident and wintering bald eagles were studied in southcentral Oregon and California, 1979-83. Food habits were assessed by examination of castings from winter communal roosts, identification of 2938 prey items found at nest sites and foraging areas, and observations...