Nutrition effects productivity of grouse. Females that obtain
high nutrient diets in spring produce larger clutches and larger, more
viable chicks than hens on less nutritious diets. Grouse select high
nutrient foods to help ensure proper nutrition. Reduced productivity
accounted for the decline of sage grouse (Centrocercus urophasianus)
populations in...
This study describes the composition and structure of forests within the immediate
vicinity of Northern spotted owl (Strix occidentalis caurina) nest sites in the Klamath,
Coast, and Cascade provinces of western Oregon and the Olympic province, Washington.
I compared forest stand data collected at 105 nest sites with data from...
I studied nest-site characteristics and habitat relationships for three species ofprimary cavity-nesting birds--hairy woodpecker (Picoides villosus), northern flicker (Colaptes auratus), and red-breasted sapsucker (Sphyrapicus ruber)-- over spatially heterogeneous landscapes in managed forests of the Southern Oregon Cascades during 1995 and 1996. The study was conducted on the Diamond Lake Ranger...
Environmental factors such as chemical contamination can have immunomodulatory effects on the immune response of fish and may be contributing to the decline in salmonid populations by augmenting disease susceptibility. Xenobiotics can interfere with the immune system at several levels of complexity, and different immune cells and processes have variable...
In small forested streams, changes in age and structure of riparian vegetation covering the stream have been shown to directly influence the amount of light reaching the stream benthos. Light has the potential to impact in-stream resources that support secondary production through constraints on primary productivity. The influence of landscape...
As more people become interested in rock climbing, the need to understand climbers and their preferences and how their activities impact the resource are more vital than ever. With increased use, and with little empirical data about the Yosemite climbing community, park managers cannot adequately develop a comprehensive climbing management...
The control of feral goats (Capra hircus) and relevant aspects of their biology were studied on Aldabra Atoll, Republic of Seychelles, from October 1993 - May 1994 and November 1994 - May 1995. A total of 832 goats were killed on Aldabra using both the Judas goat technique and traditional...
This study describes the composition of forest landscapes surrounding
northern spotted owl (Strix occidentalis caurina) nests in the central Cascade
Mountains of Oregon. I compared forest composition around 126 owl nests in 70 pair
territories with forest composition around 119 points drawn randomly from all
terrestrial cover-types, and around 104...
Biomass burning associated with deforestation and land use in the Amazon, greatly contributes to emissions as well as depletion of elemental pools. We identified deforestation and pasture formation and quantified resultant burning emissions and terrestrial aboveground elemental pool losses during a period of early colonization in the vicinity of Jamari,...
Voluntary environmental programs (VEPs) have been created to encourage companies to engage in behaviors that mitigate environmental impacts (e.g., recycling, emissions reduction). Many ski areas participate in the Sustainable Slopes Program, an initiative that promotes VEPs in the ski area industry. Past research has addressed the performance of VEPs in...
Little is known about Columbian black-tailed deer (Odocoileus hemionus columbianus) because of their elusive nature and the logistical difficulty of studying them in densely forested and mountainous terrain. The Oregon Department of Fish and Wildlife has identified fawn survival as an important gap in the current knowledge of demography and...
Dry coniferous forests in the western United States are experiencing severe wildfires, insect outbreaks, forest disease epidemics and a growing presence of invasive species. Policies strongly emphasize reducing hazardous fuels at the Wildland Urban Interface (WUI) where communities and forests intersect. However, these areas present restoration challenges as they tend...
Eight cougars were radio-collared and monitored during 1985 - 1987. Home range size, determined by minimum convex polygons, averaged 153.1 km2 for females, 543.5 km2 for males. Core home range size, determined by harmonic mean analysis, averaged 21.7 km2 for females, 17.9 km2 for males. Home ranges of males and...
For centuries in what is now southern Kenya and northern Tanzania, nomadic, Maasai livestock herders have coexisted with vast populations of wildlife. Today, both wildlife and the Maasai herding lifestyle, a vital component of Maasai culture, are threatened by changes to the landscape and losses in mobility, including the policy...
We studied the distribution and habitat selection differences between
Spanish breed (Corriente and Longhorn mix) and British breed cattle (Angus,
Hereford). This study was located on the Zumwalt prairie during the spring and
fall and along the Imnaha river for the winter. Each trial ran for two weeks and in...
I measured responses of free-ranging Rocky Mountain elk (Cervus elaphus) to recreational disturbance at Starkey Experimental Forest and Range, Oregon from April to October, 2003 and 2004. Resting, feeding, and travel activities of 13 cow elk were recorded at 5-minute intervals using Actiwatch™ motion sensors. Elk were subjected to four...
As the global demand for natural resources increases, more land will be intensively managed for the production of commodities such as timber, with potential consequences to biodiversity, ecological functioning and ecosystem services provided to society. Although there is strong consensus that intensive land management practices can negatively affect biodiversity, less...
There is a perceived trade-off between fire risk reduction and northern spotted owl habitat protection in dry-conifer forests in southwestern Oregon. Management options for balancing this trade-off need to be sought at the landscape level. Applied landscape ecology suggests three important features to consider are (1) patch size and configuration...
The Mark 0. Hatfield Marine Science Center (HMSC)
public education opportunities include interpretive programs
offered along the Estuary Nature Trail. The purpose of this
study was to determine the effectiveness of three informal
education programs, interpretive signs, a self-guided trail
brochure, and guided naturalist walks, in imparting
information on the...
Before the arrival of Euro-Americans, the inland Pacific Northwest was settled by native
people whose frequent intentional burning of the landscape promoted open stands
dominated by large fire-resistant ponderosa pine. Fire suppression for nearly a century,
livestock grazing, and logging of the largest trees has resulted in forests characterized by...
The purpose of this study was to investigate the development of an interactive
aquarium design motivated by the employment of an innovative technology used in
scientific research. The study was informed by research on free-choice learning
describing the effects of interactive devices on visitor learning, engagement, and
attitudes. The researcher...
Mountain Quail (Oreortyx pictus) populations have declined in many areas of the western Great Basin during the past century. Yet the life history of this species is little known. From 1997 to 2000, I studied radio-marked Mountain Quail in Hell's Canyon in northeastern Oregon, in the Cascade Mountains of southwestern...
To assess the consequences of increased recreational activity on bald eagles (Haliaeetus leucocephalus), we studied factors that influenced their behavior and reproductive success in the Gulkana River basin, Alaska, from 1989 to 1993. Both extrinsic and intrinsic factors were associated with reproductive success. Productivity averaged 0.86 young fledged per occupied...
On piñon-juniper encroached sites that lack the understory fuels to carry a prescribed fire, treatment options are limited to mechanical methods. Cutting with chainsaws and leaving the trees on site has been the primary treatment method for such sites, however this method creates a potential fire hazard, particularly in the...
The behavior of coniferous trees subjected to wind loading was investigated through a series of experiments and also through simulation modeling. Previous studies that measured the natural oscillation frequencies and damping ratios were reviewed and equations were developed for predicting the natural frequency of a tree from the ratio of...
Surface transient storage (STS) in stream ecosystems serve an important function in retaining nutrients and refugia for aquatic communities. Unfortunately, they can retain contaminants as well. Therefore, it is of importance to determine the residence time distribution (RTD). A RTD of a particular STS zone encompasses the time it takes...