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Use of burrow entrances to indicate densities of Townsend's ground squirrels 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...
Authors
Beatrice Van Horne, Robert L. Schooley, Steven T. Knick, Gail S. Olson, Kenneth P. Burnham

Nitrogen metabolism of sheep and goats consuming Acacia brevispica and Sesbania sesban Nitrogen metabolism of sheep and goats consuming Acacia brevispica and Sesbania sesban

We described the effects of two East African browses, Acacia brevispica and Sesbania sesban, on nitrogen metabolism of sheep and goats. The A. brevispica had a substantial amount of proanthocyanidins (condensed tannins); S. sesban did not. The browses were fed at three levels in combination with vetch (Vicia dasycarpa) and teff straw (Eragrostis abyssinica). Fecal N, N balance, and...
Authors
A. Woodward, J.D. Reed

Shorebird diet and size selection of nereid polychaetes in South Carolina coastal diked wetlands Shorebird diet and size selection of nereid polychaetes in South Carolina coastal diked wetlands

Coastal wetlands that are diked and managed may supplement declining natural habitat for migrating shorebirds (Charadriiformes). However, data on shorebird diet in these diked wetlands are scarce. We examined shorebird diet and prey size selection in brackish diked wetlands at the Yawkey Center on South Island, South Carolina, USA. Gut contents of seven Lesser Yellowlegs (Tringa flavipes...
Authors
Louise M. Weber, Susan M. Haig

Population structure of red-cockaded woodpeckers (Picoides borealis) in south Florida: RAPDs revisited Population structure of red-cockaded woodpeckers (Picoides borealis) in south Florida: RAPDs revisited

Six south Florida populations of the endangered red-cockaded woodpecker (Picoides borealis) were sampled to examine genetic diversity and population structure in the southernmost portion of the species' range relative to 14 previously sampled populations from throughout the species range. Random amplified polymorphic DNA (RAPD) analyses were used to evaluate the populations (n= 161...
Authors
Susan M. Haig, R. Bowman, Thomas D. Mullins

Effects of cutting time, stump height, parent tree characteristics, and harvest variables on development of bigleaf maple sprout clumps Effects of cutting time, stump height, parent tree characteristics, and harvest variables on development of bigleaf maple sprout clumps

In order to determine the effects of stump height, year of cutting, parent-tree size, logging damage, and deer browsing on bigleaf maple (Acer macrophyllum) sprout clump development, maple trees were cut to two stump heights at three different times. Stump height had the greatest impact on sprout clump size. Two years after clearcutting, the sprout clump volume for short stumps was...
Authors
J. C. Tappeiner, J. Zasada, D. Huffman, B. Maxwell

Can shrub cover increase predation risk for a desert rodent? Can shrub cover increase predation risk for a desert rodent?

Previous research indicates that predation risk may influence activity patterns, habitat partitioning, and community structure of nocturnal desert rodents. Shrub microhabitat is typically considered safer than open microhabitat for these small mammals. We investigated predation risk for Townsend's ground squirrels (Spermophilus townsendii), which are diurnal desert rodents that detect...
Authors
Robert L. Schooley, Peter B. Sharpe

Temperature, water chemistry, and optical properties of Crater Lake Temperature, water chemistry, and optical properties of Crater Lake

Water temperature, water chemistry, and optical properties of Crater Lake were studied from 1983 to 1991. In winter and spring, wind energy and convection mixed the water column to a depth of 200 to 250 m. The lake was thermally stratified in summer and early fall; however, the epilimnion was only 5 to 20 m thick, and most of the 589 m deep water column was a cold hypolimnion. The lake...
Authors
Gary L. Larson, C. D. McIntire, M.W. Buktenica

Factors leading to different viability predictions for a grizzly bear data set Factors leading to different viability predictions for a grizzly bear data set

Population viability analysis programs are being used increasingly in research and management applications, but there has not been a systematic study of the congruence of different program predictions based on a single data set. We performed such an analysis using four population viability analysis computer programs: GAPPS, INMAT, RAMAS/AGE, and VORTEX. The standardized demographic rates...
Authors
L. S. Mills, S.G. Hayes, M.J. Wisdom, J. Citta, D.J. Mattson, K. Murphy

Indicators of red squirrel (Tamiasciurus hudonicus) abundance in the whitebark pine zone Indicators of red squirrel (Tamiasciurus hudonicus) abundance in the whitebark pine zone

We investigated occupied squirrel middens and squirrel sightings and vocalizations as indicators of red squirrel (Tamiasciurus hudsonicus) abundance in the high-elevation whitebark pine (Pinus albicaulis) zone. Data were collected 1984-1989 from line transects located on 2 study sites in the Yellowstone ecosystem. We evaluated the performance of each measure on the basis of precision and
Authors
D.J. Mattson, Daniel P. Reinhart
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