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Explore WARC's science publications.

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USFWS selected geographic analyses USFWS selected geographic analyses

The geographic information system (GIS) used by the National Wetlands Research Center (NWRC) of the U.S. Fish and Wildlife Service has been valuable in assisting natural resource managers in planning and managing coastal fish and wildlife resources. In the past 5 years, NWRC has conducted about 60 studies employing this technology. Applications have ranged from simple natural resource...
Authors
Floyd O. Stayner, James D. Scurry, James B. Johnston, Mary C. Watzin, Pasquale F. Roscigno

Estimating wintering Bald Eagle densities in the Mississippi Alluvial Valley Estimating wintering Bald Eagle densities in the Mississippi Alluvial Valley

Surveys on the winter distribution of Bald Eagles have been concentrated in the northern USA (Hastings 1988, Mattson 1988), where Bald Eagles are most common. Few density estimates for wintering Bald Eagles exist. In the past, different survey techniques with little standardization have been used. Statistical analyses and error measurements of existing winter survey data usually are not...
Authors
Mike Brown, James R. Nassar

Global climate change: USFWS coastal research Global climate change: USFWS coastal research

Scenarios of global climate change are still ambiguous; however, increasing sea level and atmospheric carbon dioxide (CO2) concentrations seem certain, although rates of change are still being debated. Predictions for other aspects of climate change, such as temperature, tropical storm frequency and intensity, and precipitation, are still in debate, and all predictions for local (e.g...
Authors
Janet R. Keough, Thomas W. Doyle, Robert E. Stewart

Effects of site, landscape features, and fire regime on vegetation patterns in presettlement southern Wisconsin Effects of site, landscape features, and fire regime on vegetation patterns in presettlement southern Wisconsin

The presettlement tree cover (1831–33) of 3 townships in a southern Wisconsin landscape was analyzed using original survey records. Four forest types were identified: closed forest, open forest, savanna, and prairie. Comparisons of vegetation types and landscape pattern were made between the east and west sides of the Pecatonica River, which bisects the landscape and could have acted as...
Authors
Lawrence A. Leitner, Christopher P. Dunn, Glenn R. Guntenspergen, F. Stearns, David M. Sharpe

Geographic and temporal variation in the diet of Yellow-headed Blackbirds Geographic and temporal variation in the diet of Yellow-headed Blackbirds

Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) are presumed predators of sunflower (Helianthus annuus) in the northern Great Plains. Their esophageal contents varied temporally and among three provinces and three states in relation to regional agricultural bases but males contained more sunflower and small grains than females whereas females contained more weed seeds and...
Authors
Daniel J. Twedt, William J. Bleier, George M. Linz

The measurement of mangrove characteristics in southwest Florida using spot multispectral data The measurement of mangrove characteristics in southwest Florida using spot multispectral data

An intensive in situ sampling program near Marco Island, Florida during 19–23 October 1988 collected information on mangrove type, maximum canopy height, and percent canopy closure. These data were correlated with selected vegetation index information derived from analysis of SPOT multispectral (XS) data obtained on 21 October 1988. The Normalized Difference (ND) vegetation index...
Authors
John R. Jensen, Hongyue Lin, Xinghe Yang, Elijah Ramsey III, Bruce M. Davis, Chris W. Thoemke

Fishes Fishes

No abstract available.
Authors
Noel M. Burkhead, R.E. Jenkins

Additions to the ichthyofauna of the Bahama Islands, with comments on endemic species Additions to the ichthyofauna of the Bahama Islands, with comments on endemic species

Literature records or other documentation are given for 57 species of shorefishes added to the Bahaman ichthyofauna since publication of Fishes of the Bahamas; included are 32 new species described or discovered since 1967. Known distribution is specified for each species, including extralimital ranges of non-endemics. Fourteen species are listed as known only from the Bahamas although...
Authors
William F. Smith-Vaniz, Eugenia B. Bohlke
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