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Taricha granulosa (Rough-skinned newt). Summer habitat and aggregation. Taricha granulosa (Rough-skinned newt). Summer habitat and aggregation.

Terrestrial behavior and habitat associations of post-metamorphic Taricha granulosa are poorly understood (Oliver and McCurdy 1974. Can. J. Zool. 52:541-545; Pimentel 1960. Amer. Midl. Nat. 63:470-496). Chandler (1918. Oregon Agric. Coll. Exper. Sta. Bull. 152:6) referenced Fall T granulosa aggregations in "cavities under stumps, logs, and stones," but does not present specific data...
Authors
Christopher A. Pearl

Modeling approaches in avian conservation and the role of field biologists Modeling approaches in avian conservation and the role of field biologists

This review grew out of our realization that models play an increasingly important role in conservation but are rarely used in the research of most avian biologists. Modelers are creating models that are more complex and mechanistic and that can incorporate more of the knowledge acquired by field biologists. Such models require field biologists to provide more specific information...
Authors
Steven R. Beissinger, J. R. Walters, D.G. Catanzaro, Kimberly G. Smith, J.B. Dunning, Susan M. Haig, Barry Noon, Bradley Stith

Coupled nitrogen and calcium cycles in forests of the Oregon Coast Range Coupled nitrogen and calcium cycles in forests of the Oregon Coast Range

Nitrogen (N) is a critical limiting nutrient that regulates plant productivity and the cycling of other essential elements in forests. We measured foliar and soil nutrients in 22 young Douglas-fir stands in the Oregon Coast Range to examine patterns of nutrient availability across a gradient of N-poor to N-rich soils. N in surface mineral soil ranged from 0.15 to 1.05% N, and was...
Authors
S.S. Perakis, D.A. Maguire, T.D. Bullen, K. Cromack, R.H. Waring, J.R. Boyle

Do migratory flight paths of raptors follow constant geographical or geomagnetic courses? Do migratory flight paths of raptors follow constant geographical or geomagnetic courses?

We tested whether routes of raptors migrating over areas with homogeneous topography follow constant geomagnetic courses more or less closely than constant geographical courses. We analysed the routes taken over land of 45 individual raptors tracked by satellite-based radiotelemetry: 25 peregrine falcons, Falco peregrinus, on autumn migration between North and South America, and seven...
Authors
K. Thorup, M. Fuller, T. Alerstam, M. Hake, N. Kjellen, R. Strandberg

Spatial structure in the diet of imperial eagles Aquila heliaca in Kazakhstan Spatial structure in the diet of imperial eagles Aquila heliaca in Kazakhstan

We evaluated the relationship between spatial variability in prey and food habits of eastern imperial eagles Aquila heliaca at a 90,000 ha national nature reserve in north-central Kazakhstan. Eagle diet varied greatly within the population and the spatial structure of eagle diet within the population varied according to the scale of measurement. Patterns in dietary response were...
Authors
T.E. Katzner, E. A. Bragin, S.T. Knick, A.T. Smith

Factors influencing nest success of songbirds in aspen and willow riparian areas in the Great Basin Factors influencing nest success of songbirds in aspen and willow riparian areas in the Great Basin

Recent studies have examined the effects of livestock grazing, agriculture, and human habitation on nest predation and brood parasitism in riparian areas in the western United States. However, we know little about factors influencing nest success in riparian areas lacking such anthropogenic influences, in part because the influences are so pervasive. We studied riparian bird communities...
Authors
J.M. Heltzel, S.L. Earnst

Effects of feral horses in Great Basin landscapes on soils and ants: Direct and indirect mechanisms Effects of feral horses in Great Basin landscapes on soils and ants: Direct and indirect mechanisms

We compared soil-surface penetration resistance and abundance of ant mounds at 12 western Great Basin sites (composed of 19 plots) either grazed by feral horses (Equus caballus) or having had horses removed for the last 10–14 years. Across this broad spatial domain (3.03 million ha), we minimized confounding due to abiotic factors by selecting horse-occupied and horse-removed sites with...
Authors
E.A. Beever, J. E. Herrick

Size dimorphism, molt status, and body mass variation of Prairie Falcons nesting in the Snake River Birds of Prey National Conservation Area Size dimorphism, molt status, and body mass variation of Prairie Falcons nesting in the Snake River Birds of Prey National Conservation Area

Birds face challenges in how they allocate energy during the reproductive season. Most temperate zone species do not breed and molt at the same time, presumably because of the high energy demands of these two activities (Espie et al. 1996 and citations therein). However, representatives of at least four raptor genera are known to molt during the nesting season (Schmutz and Schmutz 1975...
Authors
Karen Steenhof, James O. McKinley

Emerging concepts for management of river ecosystems and challenges to applied integration of physical and biological sciences in the Pacific Northwest, USA Emerging concepts for management of river ecosystems and challenges to applied integration of physical and biological sciences in the Pacific Northwest, USA

Integration of biological and physical concepts is necessary to understand and conserve the ecological integrity of river systems. Past attempts at integration have often focused at relatively small scales and on mechanistic models that may not capture the complexity of natural systems leaving substantial uncertainty about ecological responses to management actions. Two solutions have...
Authors
Bruce Rieman, Jason B. Dunham, James Clayton

Monitoring biological diversity: strategies, tools, limitations, and challenges Monitoring biological diversity: strategies, tools, limitations, and challenges

Monitoring is an assessment of the spatial and temporal variability in one or more ecosystem properties, and is an essential component of adaptive management. Monitoring can help determine whether mandated environmental standards are being met and can provide an early-warning system of ecological change. Development of a strategy for monitoring biological diversity will likely be most...
Authors
E.A. Beever
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