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Publications

Publications from USGS science centers throughout the Southeast Region.

Filter Total Items: 10361

Seasonal distribution, movements and habitat associations of northern squawfish in two Lower Columbia River reservoirs Seasonal distribution, movements and habitat associations of northern squawfish in two Lower Columbia River reservoirs

We tracked 335 northern squawfish implanted with radio transmitters in the Columbia River in May–December 1993 and May–September 1994. Most fish were released near The Dalles and John Day dams, with the remaining fish released into reservoir areas away from dams. We used boats with mounted Yagi antennas, fixed site receiver stations near the dams and aerial surveys to track movements of...
Authors
Theresa L. Martinelli, Rip S. Shively

Relative costs of prebasic and prealternate molts for male blue-winged teal Relative costs of prebasic and prealternate molts for male blue-winged teal

We compared masses of definitive basic and alternate plumages of male Blue-winged Teal (Anas discors) to evaluate the hypothesis that nutritional investments in basic and alternate plumages are related to the duration that plumages are worn and to assess the relative costs of prebasic and prealternate molts. Because these plumages are worn by males for approximately equal durations, we...
Authors
W.L. Hohman, S.W. Manley, D. Richard

Use of inexpensive pressure transducers for measuring water levels in wells Use of inexpensive pressure transducers for measuring water levels in wells

Frequent measurement of below ground water levels at multiple locations is an important component of many wetland ecosystem studies. These measurements, however, are usually time consuming, labor intensive, and expensive. This paper describes a water-level sensor that is inexpensive and easy to construct. The sensor is placed below the expected low water level in a shallow well and, when...
Authors
B. D. Keeland, J.F. Dowd, W.S. Hardegree

Long-term growth trends of baldcypress (Taxodium distichum (L.) rich.) at Caddo Lake, Texas Long-term growth trends of baldcypress (Taxodium distichum (L.) rich.) at Caddo Lake, Texas

Caddo Lake, situated on the border of northeast Texas and northwest Louisiana, USA is a medium-sized lake dominated by stands of baldcypress (Taxodiwn distichum). A study of tree growth was initiated at Caddo Lake to address concerns about the health of the baldcypress ecosystem. The lake has been subjected to several dramatic water-level changes over the past 200 years, including water...
Authors
B. D. Keeland, P.J. Young

Source-sink dynamics and the coexistence of species on a single resource Source-sink dynamics and the coexistence of species on a single resource

We investigate the potential for coexistence of species that compete for a shared resource when the resource occurs in both a source area acting as a refuge and a sink area where it is used by the competing species. Our model shows that the mixing rate between the source and sink resource populations has a dramatic influence on the outcome of competition. When there is a strict sink...
Authors
M. Loreau, D.L. DeAngelis

Hydrogeologic framework of western Cape Cod, Massachusetts Hydrogeologic framework of western Cape Cod, Massachusetts

The aquifer of western Cape Cod consists of several hydrogeologic units composed of sand, gravel, silt, and clay (fig. 1) that were deposited during the late Wisconsinan glaciation of New England. The aquifer is a shallow, unconfined hydrologic system in which ground-water flows radially outward from the apex of the ground-water mound near the center of the peninsula toward the coast...
Authors
John P. Masterson, Byron D. Stone, Donald A. Walter, Jennifer G. Savoie

Coastal wetlands and climate change Coastal wetlands and climate change

Abstract has not been submitted
Authors
G.R. Guntenspergen, B.A. Vairin, V.R. Burkett, D. McGrath
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