The northern goshawk (Accipiter gentilis) is a species of concern in the western United States due to its association with mature structural stage forests. I employed a use-versus-availability study design to quantify the vegetative, physiographic, and landscape variables associated with goshawk breeding habitat selection in the San Juan Mountains of...
Population size of Clavibacter michiganensis subsp.
sepedonicus in potato cv Russet Burbank and plant response
as affected by drought were assessed in a greenhouse
experiment. Water deficit stress and no stress treatments,
and inoculum densities of 0 or 2 X 10⁷ cfu C. m.
sepedonicus/seed piece were arranged factorially. Stem...
Urban ecosystems are characterized by human disturbance and changes in the amount, types, and spatial arrangement of wildlife habitat. The relative importance of habitat and human associated variables to urban birds is unknown. In 1999, I surveyed spring bird and plant communities along 54 perennial streams
in the Portland, Oregon...
Riparian zones provide habitat for breeding birds in the semiarid western United States; however, there are few data available that address the effects of livestock grazing strategies on riparian habitats and avian communities. Documenting avian community composition in different riparian vegetation communities and relating vegetation communities to livestock grazing strategies...
Nine Prairie Falcons (Falco mexicanus) were radio-tagged
in northern California during the spring and summer
of 1976 and 1977 to study foraging behavior. The mean home
range size for 3 males was 227.8 km²; largest portions of
the home range were used during the incubation period.
Shifts in foraging areas...
The combined effects of habitat loss, degradation, and fragmentation pose a serious threat to Earth's biodiversity, imperiling even relatively common species. 'Habitat' is necessarily a species-specific concept, and investigations of bird diversity relationships and subsequent efforts to prioritize conservation areas, are challenged by the difficulty of estimating complex habitat gradients...
Increasing rates of species imperilment and the loss of biological diversity in naturally functioning ecosystems can be directly linked to accelerated urban development and the conversion of natural habitats to satisfy the needs of man. In combating this loss of biodiversity, scientists and policy makers alike recognize the relevance of...
Freshwater wetlands in the Sacramento Valley provide breeding, wintering, foraging and stopover habitat for migratory and resident birds. With a loss of 95% of historic freshwater wetlands, the restoration of wetlands on private land could provide important habitat for birds. Documentation and monitoring of bird use on previously restored wetlands...
Over the last 50 years, riparian zones in the semi-arid West have gained recognition as disproportionately important habitats for both breeding bird communities and agricultural operations. Despite growing interest in exploring avian-habitat relationships in these systems to better inform land management, few studies have attempted to describe temporal changes in...