Publications
These publications showcase the significant science conducted in our Science Centers.
Filter Total Items: 16746
Standard test methods for measuring the toxicity and bioaccumulation of sediment-associated contaminants, ASTM E1706-95a Standard test methods for measuring the toxicity and bioaccumulation of sediment-associated contaminants, ASTM E1706-95a
No abstract available.
Authors
C.G. Ingersoll, F.J. Dwyer, P. V. Winger, G.A. Burton, G.T. Ankley, T. J. Norberg-King, R.A. Hoke, D. Bedard, K. Day, P. Landrum
Population trends of the loggerhead shrike from the North American Breeding Bird Survey Population trends of the loggerhead shrike from the North American Breeding Bird Survey
North American Breeding Bird Survey data indicated a general decline in Loggerhead Shrike (Lanius ludovicianus) populations during 1966-1993. At the continental level, shrikes declined at an average rate of 2.9% per year. Average rates of regional declines varied from 2.5-3.4% annually. These declines were prevalent in most states, provinces, and physiographic strata. Only the Edwards...
Authors
B.G. Peterjohn, J.R. Sauer
Changing land use: Problems and opportunities Changing land use: Problems and opportunities
Under the pressure of increasing human populations and expanding demands for food and fiber, native tropical and temperate habitats are becoming more restricted, and populations of many resident and migratory birds are declining. Mist net surveys of 111 forest and agricultural sites in Mexico, Belize, and Guatemala show that some migratory species use a wide variety of habitats during...
Authors
C.S. Robbins, D.K. Dawson, B.A. Dowell
Neotropical migrant landbirds and landscape changes in Los Tuxtlas, Veracruz, Mexico Neotropical migrant landbirds and landscape changes in Los Tuxtlas, Veracruz, Mexico
Faced with the problem of habitat loss and with the need to preserve the remaining components of the original avian biodiversity in neotropical regions such as Los Tuxtlas, it is imperative to determine how the neotropical migrant bird species have responded to the anthropogenic alterations of their natural habitats. To provide data in this direction, we censused neotropical migrant...
Authors
A. Estrada, R. Coates-Estrada, E. Diaz-Islas, C.S. Robbins, B.A. Dowell, D. Meritt
Accuracy of migrant landbird habitat maps produced from LANDSAT TM data: Two case studies in southern Belize Accuracy of migrant landbird habitat maps produced from LANDSAT TM data: Two case studies in southern Belize
The study investigated the utility of Landsat TM data applied to produce geo-referenced habitat maps for two study areas (Toledo and Stann Creek). Locational and non-site-specific map accuracy was evaluated by stratified random sampling and statistical analysis of satellite classification (SCR) versus air photo interpretation results (PIR) for the overall classification and individual...
Authors
J.P. Spruce, S. Sader, C.S. Robbins, B.A. Dowell
On the use of secondary capture-recapture samples to estimate temporary emigration and breeding proportions On the use of secondary capture-recapture samples to estimate temporary emigration and breeding proportions
The use of the Cormack- Jolly-Seber model under a standard sampling scheme of one sample per time period, when the Jolly-Seber assumption that all emigration is permanent does not hold, leads to the confounding of temporary emigration probabilities with capture probabilities. This biases the estimates of capture probability when temporary emigration is a completely random process, and...
Authors
W. L. Kendall, J.D. Nichols
Patterns of prey selection by wolves in Denali National Park, Alaska Patterns of prey selection by wolves in Denali National Park, Alaska
The patterns of selection by wolves (Canis lupus) preying on moose (Alces alces), caribou (Rangifer tarandus), and Dall sheep (Ovis dalli) in Denali National Park and Preserve, Alaska were studied from 1986 through early 1992. Wolves and their prey are legally protected or relatively unharvested in most of the area, and wolf numbers doubled during the study. Based on remains of 294 moose...
Authors
L. David Mech, T.J. Meier, John W. Burch, Layne G. Adams
Sample size and allocation of effort in point count sampling of birds in bottomland hardwood forests Sample size and allocation of effort in point count sampling of birds in bottomland hardwood forests
To examine sample size requirements and optimum allocation of effort in point count sampling of bottomland hardwood forests, we computed minimum sample sizes from variation recorded during 82 point counts (May 7-May 16, 1992) from three localities containing three habitat types across three regions of the Mississippi Alluvial Valley (MAV). Also, we estimated the effect of increasing the...
Authors
W.P. Smith, D.J. Twedt, R.J. Cooper, D.A. Wiedenfeld, P.B. Hamel, R.P. Ford
Loss of antigenicity in the progeny of an apparently healthy population of brook trout Loss of antigenicity in the progeny of an apparently healthy population of brook trout
No abstract available at this time
Authors
C. E. Starliper, J.D. Teska
Evolution of tholeiitic diabase sheet systems in the eastern United States: examples from the Culpeper Basin, Virginia-Maryland, and the Gettysburg Basin, Pennsylvania Evolution of tholeiitic diabase sheet systems in the eastern United States: examples from the Culpeper Basin, Virginia-Maryland, and the Gettysburg Basin, Pennsylvania
High-TiO2, quartz-normative (HTQ) tholeiite sheets of Early Jurassic age have intruded mainly Late Triassic sedimentary rocks in several early Mesozoic basins in the eastern US. Field observations, petrographic study, geochemical analyses and stable isotope data from three HTQ sheet systems were used to develop a general model of magmatic differentiation and magmatic-hydrothermal...
Authors
Laurel G. Woodruff, A.J. Froelich, Harvey E. Belkin, D. Gottfried
Silt fraction heavy-mineral distributions in a lateritic environment: The rivers and insular shelf of north-central Puerto Rico Silt fraction heavy-mineral distributions in a lateritic environment: The rivers and insular shelf of north-central Puerto Rico
This fraction, which is enriched in heavy minerals relative to the sand fraction, is mainly detrital but contains a strong authigenic component. The authigenic silt heavy-mineral fraction is largely a product of the lateritic weathering and dominated by iron oxides and alterites. Grains of bladed rutile and leached ilmenite are common. Spatial variability in silt-fraction mineralogy is
Authors
L.J. Poppe, J.A. Commeau, G. Luepke