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Publications

Filter Total Items: 1994

Perception of neighboring plants by rhizomes and roots: Morphological manifestations of a clonal plant

A previous study showed that clonal morphology of the rhizomatous grass Elymus lanceolatus ssp. lanceolatus (Scibner & J.G. Smith Gould) was influenced more by neighbouring root systems than by the local distribution of nutrients. In this study we determine whether individual rhizomes or roots of E. lanceolatus perceive neighbouring root systems and how this is manifested in morphological response
Authors
Elisabeth Huber-Sannwald, M. M. Caldwell, David A. Pyke

Field studies on pesticides and birds: Unexpected and unique relations

We review the advantages and disadvantages of experimental and field studies for determining effects of pesticides on birds. Important problems or principles initially discovered in the field include effects of DDT (through its metabolite DDE) on eggshell thickness, reproductive success, and population stability; trophic-level bioaccumulation of the lipid-soluble organochlorine pesticides; indirec
Authors
Lawrence J. Blus, Charles J. Henny

Supervised classification of Landsat thematic mapper imagery in a semi-arid rangeland by nonparametric discriminant analysis

In this article the authors used a nonparametric discriminant function in a supervised classification of Landsat Thematic Mapper satellite imagery of a ~240,000-ha semi-arid region in the Snake River Plains, southwestern Idaho. First, agriculture pixels were classified by distance from the soil baseline and water pixels by the thermal band value. Next, successive nonparametric discriminant functio
Authors
Steven T. Knick, J.T. Rotenberry, T.J. Zarriello

Spring feeding on ungulate carcasses by grizzly bears in Yellowstone National Park

We studied the spring use of ungulate carcasses by grizzly bears (Ursus arctos horribilis) on ungulate winter ranges in Yellowstone National Park. We observed carcasses and bear tracks on survey routes that were travelled biweekly during spring of 1985-90 in the Firehole-Gibbon winter range and spring of 1987-90 in the Northern winter range. The probability that grizzly bears used a carcass was po
Authors
Gerald I. Green, D.J. Mattson, J.M. Peek

Statistical power analysis in wildlife research

Statistical power analysis can be used to increase the efficiency of research efforts and to clarify research results. Power analysis is most valuable in the design or planning phases of research efforts. Such prospective (a priori) power analyses can be used to guide research design and to estimate the number of samples necessary to achieve a high probability of detecting biologically significant
Authors
R.J. Steidl, J. P. Hayes

The influence of habitat, prey abundance, sex, and breeding success on the ranging behavior of Prairie Falcons

We studied the ranging behavior and habitat selection of radio-tagged Prairie Falcons (Falco mexicanus) during the breeding season in southwestern Idaho. The distribution and numbers of Townsend's ground squirrels (Spermophilus townsendii), the primary prey of Prairie Falcons in our study area, varied in response to drought during the study period. Prairie Falcons ranged over large areas (ca. 300
Authors
J.M. Marzluff, Bryan A. Kimsey, Linda S. Schueck, Mary E. McFadzen, M.S. Vekasy, James C. Bednarz

Why do international research and management?

The pheasant, in its North American range, seems to have had its greatest success in glaciated or in other areas associated with calcareous soils. Success has been slight in areas deficient in calcium.....In Lancaster County, Pennsylvania, no environmental difference other than presence or absence of limestone was discovered that might explain the high population in the limestone valley and the sc
Authors
Todd K. Fuller, Mark R. Fuller, R.M. DeGraaf

Use of burrow entrances to indicate densities of Townsend's ground squirrels

Counts of burrow entrances have been positively correlated with densities of semi-fossorial rodents and used as an index of densities. We evaluated their effectiveness in indexing densities of Townsend's ground squirrels (Spermophilus townsendii) in the Snake River Birds of Prey National Conservation Area (SRBOPNCA), Idaho, by comparing burrow entrance densities to densities of ground squirrels es
Authors
Beatrice Van Horne, Robert L. Schooley, Steven T. Knick, G.S. Olson, K.P. Burnham

Landscape characteristics of disturbed shrubsteppe habitats in southwestern Idaho (USA)

We compared 5 zones in shrubsteppe habitats of southwestern Idaho to determine the effect of differing disturbance combinations on landscapes that once shared historically similar disturbance regimes. The primary consequence of agriculture, wildfires, and extensive fires ignited by the military during training activities was loss of native shrubs from the landscape. Agriculture created large squar
Authors
Steven T. Knick, J.T. Rotenberry