The United States Fish and Wildlife Service currently uses fire as a management tool to improve Greater Sage Grouse (Centrocercus urophasianus Bonaparte) nesting and brood-rearing habitat at Hart Mountain National Antelope Refuge (HMNAR) in S.E. Oregon. Previous studies at HMNAR revealed use of burned areas by sage grouse throughout the...
From 1987-1997, Oregon State University conducted studies at Hart Mountain National Antelope Refuge (HMNAR) to better understand the relationship between grouse productivity and key habitat components. Early studies indicated sage grouse habitat preference and reproductive success were related to particular forbs (including legumes and milky juice composites) and structural characters...
Greater Sage-Grouse (Centrocercus urophasianus) have experienced declines throughout their range over the last 50 years. Long-term declines in sage-grouse abundance in Nevada and Oregon have been attributed to reduced productivity. From 1995-1997, sage-grouse production on Sheldon National Wildlife Refuge (SNWR), Nevada was greater compared to Hart Mountain National Antelope Refuge...
Remote sensing techniques have long been useful in quantifying changes in ecosystems and the field of remote sensing is constantly evolving to better assess and describe changes, both spatially and temporally. In this thesis I explored the novel use of two remote sensing methods to quantify ecosystems; repeat photograph to...
Pygmy rabbits (Brachylagus idahoensis) in Oregon and Washington are a sagebrush (Artemisia tridentata spp.) obligate species of concern because of declining populations and extirpation from much of their range. Efforts are underway to establish a captive bred population of the Columbia Basin pygmy rabbit in Washington state for reintroduction into...
Hart Mountain is a basaltic fault block mountain
in the semi-desert region of the northern Basin and Range
province in south-central Oregon. Geomorphic processes
associated with lingering snowpatches have formed nivation
hollows, which are small scale depressions in the hillsides.
The lingering snow in the hollows prohibits shrub
growth. Bedrock...
Heavy use of outdoor recreation areas in the United States
since World War II is endangering their quality. Demand made by a
rapidly growing population with rising personal incomes and increasing
leisure time is expected to grow 50 percent nationally and 146 percent in Oregon by 1975. In Oregon, population,...
Decline of western sage grouse (Centrocercus urophasianus phaios)
in Oregon may be related to the reduced availability of foods in upland
sagebrush (Artemisia)-grasslands used for brood-rearing. The goal of
this study was to determine primary foods of chicks and the short-term
response of brood-rearing habitat to prescribed burning at Hart...
California bighorn sheep (Ovis canadensis californiana) were studied on Hart Mountain, Oregon, during the summer and fall of 1976, and the spring of 1977. The population consisted of a minimum of 196 sheep in June, 1977. The high number of lambs observed and high lamb:ewe ratios throughout both years of...
A herd of California bighorn sheep (Ovis canadensis californiana),
re-introduced to the area of Hell Creek on the Sheldon National
Wildlife Refuge in northwestern Nevada, was studied from 15 June 1978
to 20 August 1980.
Major vegetation and physiographic types were delineated and
described. Habitat preferences were determined from field...
Sage grouse are a species of concern because their abundance, distribution, and productivity have declined during the past century. Sage grouse productivity has been linked to specific habitat components including particular forbs and native bunchgrasses. Studies on the effects of fire were conducted in Southeastern Oregon in mountain big sagebrush...
I investigated survival, movements, home range sizes, and habitat selection of pygmy rabbits (Brachylagus idahoensis) in southeastern Oregon and northwestern Nevada from June 2005 to June 2007. I trapped 298 rabbits on four sites and fitted each with radio transmitters. More than 13,000 locations of telemetered rabbits were recorded. I...
Anthropogenic land use alterations such as livestock grazing and fire
suppression have greatly altered sagebrush grasslands of the Great Basin,
facilitating invasion of exotic annuals, increases in woody species, and losses of
native species. Much of the current research surrounding wildland and prescribed
fire in sagebrush dominated ecosystems has focused...
Historically fire has been the primary disturbance factor in the sagebrush-steppe. The settlement of the West by Euro-Americans, grazing by domestic livestock, and the concomitant spread of invasive species have altered the historical fire regime. Understanding the long-term vegetation structure and fuel succession of the various sagebrush-dominated communities of this...
Sage grouse (Centrocercus urophasianus) populations in Oregon
declined during the past 30 years as a result of impaired productivity.
The western subspecies (C. u. phaios) was listed as a candidate for
threatened and endangered status by the Department of the Interior in
1985 because of declines in Oregon and Washington...
Recent developments in Distributed Temperature Sensing (DTS) have allowed new insight into the surface-to-ground water interaction. The continuous temperature measurement by the DTS allows for cool water inflows to be located during warm summer months. These cool water inflows can then be differentiated between ground water and hyporheic exchange. The...
Similar to other spectacular scenic areas in the American West, Idaho’s White Cloud Mountains have been a contested landscape since the beginning of the 20th century. Although, legislation was introduced in Congress as early as 1913 to protect the towering mountains of south-central Idaho as a national park, the issue...
Relative use by pronghorns (Antilocapra americana) of 16 range sites was studied during summer and fall of 1971 and 1972 on Hart Mountain National Antelope Refuge, an area of high desert
rangeland in south central Oregon. A Relative Use Index was developed based upon 1533 observations of pronghorns located on...
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...
