Publications
Filter Total Items: 1990
Crested wheatgrass-cheatgrass seedling competition in a mixed-density design
Plant competition experiments have historically used designs that are difficult to interpret due to confounding problems. Recently, designs based on a 'response function' approach have been proposed and tested in various plant mixture settings. For this study, 3 species were used that are important in current revegetation practices in the Intermountain West. 'Nordan' (Agropyron desertorum [Fish. e
Authors
Mark G. Francis, David A. Pyke
Chemical solute mass balance of Crater Lake, Oregon
Crater Lake covers the floor of the caldera at the top of Mount Mazama. Surrounded by steep walls, the water surface of the lake occupies 78 percent of the catchment basin. No major rivers empty into the lake, and there is no surface outlet Based on a chemical solute mass balance model, mass inputs of major solute chemical components (Na, Ca, K, Mg, SO4, Cl, Si, and HCO3) from atmospheric depositi
Authors
Peter O. Nelson, J.F. Reilly, Gary L. Larson
Influence of radio transmitters on prairie falcons (Falco mexicanus)
We examined the effects of backpack radio transmitters on Prairie Falcon (Falco mexicanus) reproduction (percentage of occupied territories producing young and number of nestlings produced) over four years. In addition, we observed falcon aeries during brood-rearing to determine attendance at the nest and in the territory, prey delivery rates, and prey composition. We found no effect of radio tagg
Authors
M.S. Vekasy, J.M. Marzluff, Michael N. Kochert, Robert N. Lehman, Karen Steenhof
Diet and trophic characteristics of great horned owls in southwestern Idaho
We studied the diet of Great Horned Owls (Bubo virginianus) in the Snake River Birds of Prey National Conservation Area in southwestern Idaho for 14 breeding seasons. The diet included 89.2% mammals by number and 91.2% by mass. Kangaroo rats (Dipodomys spp.) were the most common prey overall, but montane voles (Microtus montanus), Peromyscus spp., Great Basin pocket mice (Perognathus parvus) and T
Authors
C.D. Marti, Michael N. Kochert
Overview of the limnology of Crater Lake
Crater Lake occupies the collapsed caldera of volcanic Mount Mazama in Crater Lake National
Park, Oregon. It is the deepest lake (589 m) in the United States and the 7th deepest lake in the world. The water column mixes to a depth of about 200 m in winter and spring from wind energy and cooling. The deep lake is mixed in winter and early spring each year when relatively cold water near the surfac
Authors
Gary L. Larson
Contaminants and sea ducks in Alaska and the circumpolar region
We review nesting sea duck population declines in Alaska during recent decades and explore the possibility that contaminants may be implicated. Aerial surveys of the surf scoter (Melanitta perspicillata), white-winged scoter (M. fusca), black scoter (M. nigra), oldsqaw (Clangula hyemalis), spectacled eider (Somateria fischeri), and Steller's eider (Polysticta stellei) show long-term breeding popul
Authors
Charles Henny, Deborah D. Rudis, Thomas J. Roffe, Everett Robinson-Wilson
The use of satellite systems for the study of bird migration
The Argos satellite system, with two or more polar-orbiting satellites, provides the basis for receiving radio signals from transmitters and for estimating locations of those transmitters anywhere around the earth. We briefly relate the development of platform-transmitter terminals small enough to be placed on birds, but powerful enough to send signals to the satellites. We review the use of this
Authors
Mark R. Fuller, W. Seegar, Paul Howey
Survival and population size estimation in raptor studies: A comparison of two methods
ABSTRACT.--The Jolly-Seber model is a capture-recapture model that can provide less-biased survival and population size estimates than those produced from simple counting procedures. Parameter estimation by simple counts and Jolly-Seber methods are based on certain assumptions that directly determine the validity of estimates. Evuluation of assumptions for parameter estimation is a focus of this p
Authors
William R. Gould, Mark R. Fuller
Landscape characteristics of fragmented shrubsteppe habitats and breeding passerine birds
We examined the influence of local and landscape-level attributes of fragmented habitats in shrubsteppe habitats on the breeding distributions of Sage (Amphispiza belli) and Brewer's (Spizella breweri) Sparrows, Sage Thrashers (Oreoscoptes montanus), Horned Larks (Eremophila alpestris), and Western Meadowlarks (Sturnella neglecta) in the Snake River Plains of southwestern Idaho. We developed habit
Authors
Steven T. Knick, J.T. Rotenberry
Are red-tailed hawks and great horned owls diurnal-nocturnal dietary counterparts?
Red-tailed Hawks (Buteo jamaicensis) and Great Homed Owls (Bubo virginianus)are common in North America where they occupy a wide range of habitats, often sympatrically. The two species are similar in size and have been portrayed as ecological counterparts, eating the same prey by day and night. We tested the trophic similarity of the two species by comparing published dietary data from across the
Authors
C.D. Marti, Michael N. Kochert
Ecology and breeding biology of the Hawaii elepaio (Chasiempis sandwichensis bryani)
No abstract available.
Authors
Charles van Riper
Competitive relations between Douglas-fir and Pacific madrone on shallow soils in a Mediterranean climate
A large area of Pacific Coast forests is characterized by shallow soil, with negligible rainfall in the growing season. This study explores water-seeking strategy on such a site. We studied availability of bedrock water and its effects on growth and ecophysiology of 11-yr-old planted Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and sprouting Pacific madrone (Arbutus menziesii Pursh). The stu
Authors
Zheng Q. Wang, M. Newton, J. C. Tappeiner