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At least 19 recordsLinked to original sources
USGS1985

Food and feeding of fish in Hartwell Reservoir tailwater, Georgia-South Carolina

Food of silver redhorse (Moxostoma anisurum), redbreast sunfish (Lepomis auritus), green sunfish (L. cyanellus), and bluegills (L. macrochirus) was examined to determine whether or not these fish in the Hartwell Reservoir tailwater (Savannah River, Georgia-South Carolina) ate organisms entrained from the reservoir or displaced from the tailwater during water releases associated with the production of hydropower. These fish fed primarily on aquatic insects, crayfish, and terrestrial organisms originating from the tailwater. Major periods of feeding occurred during nongeneration.

Proceedings of the Annual Conference of the Southe↗
USGS1980

Situation report: Heavy DDT contamination at Wheeler National Wildlife Refuge

A DDT manufacturing plant that operated on the Redstone Arsenal near Huntsville, Alabama discharged DDT-Iaden effluent from 1947 to 1970 into a creek on Wheeler National Wildlife Refuge. Seven to 9 years after the plant closed, high DDT, DDE, and DDD levels were reported in soils, river sediments, and fish in the area. Eleven of 27 mallards (Anas platyrhynchos) collected on the Refuge during February 1979 had carcass DDE residues that exceeded levels associated with eggshell thinning. DDE residues in a smaller number of mallards exceeded levels associated with egg breakage, poor hatchability, and abnormal hehavior and poor survival of offspring. Several avian species have disappeared from the Refuge since 1950, probably due to both industrial discharges of DDT from the plant and insecticidal use of DDT in the area. The contamination still presents a threat to herons, waterfowl, and raptors including occasional wintering or migrant eagles (Haliaeetus leucocephalus), and probably many other avian species. A maternity colony of endangered gray bats (Myotis grisescens) is also threatened by this contamination.

Proceedings of the Annual Conference of the Southe↗
USGS1985

PCBs, organochlorine pesticides, and reproduction in river otters from Louisiana

Reproductive tracts from 89 3-year-old female river otters (Lutra canadensis), from Louisiana were examined. Eighteen of these were in a reproductive phase out of synchrony with the expected population norms. Eight of 32 otters had fewer embryos than corpora lutea, indicating intrauterine mortality in 25% of the sample. Chemical analyses of liver tissue from 57 otters revealed a low prevalence of polychlorinated biphenyls (PCB) and organochlorine pesticide contamination. These low Ievels of organochlorine compounds were not associated with atypical reproductive synchrony or intrauterine mortality.

Proceedings of the Annual Conference of the Southe↗
USGS1978

Rehabilitation of birds oiled on two mid-Atlantic estuaries

An estimated 52,500 birds died as a result of 7 major oil spills on 2 mid-Atlantic estuaries between 1973-78. Ruddy ducks ( Oxyura jamaicensis ) constituted 98% of 12,500 birds known to have died from 5 spills on the Delaware River. Seventy-six percent of 40,000 dead birds from 2 Chesapeake Bay spills were horned grebes ( Podiceps auritus ) and oldsquaw ( Clangula hyemalis ). Oiled waterfowl that were captured alive (6% of the estimated mortality) were cleaned with a variety of cleaning agents and techniques. High mortality occurred during and shortly after cleaning, and was apparently due to hypothermia and to toxicity of solvent cleaning agents. Eighty-two percent of the 3,113 birds that were cleaned died prior to or at time of release. The fate of the remaining 18% is unknown. Petroleum solvents used as cleaning agents were toxic to the birds. Most detergents left a surfactant (wetting agent) on the feathers which resulted in subsequent wetting of released birds. Although rehabilitation techniques have improved in recent years, high bird mortality can be expected following future oil spills.

Chesapeake Bay, Delaware River↗
USGS1991

Movements and survival of American black duck and mallard broods on Chesapeake Bay

We attached radio transmitters to day-old American black duck (Anas rubripes) and mallard (A. platyrhynchos) ducklings and monitored duckling habitat use, brood movements, and survival rates for 30 days. Ducklings moved an average of 2.3 km within the first 24 hours and another 1.5 km thereafter. After the initial move, broods usually moved once more. No differences in initial movement distance, subsequent movement distance, or total number of movements were found between black duck and mallard broods. There was some evidence that broods in more human developed areas moved more than broods in less human-developed areas. Black duck duckling survival rates were greater than mallard survival rates in 1 of 2 study years.

Chesapeake Bay↗
USGS1982

Food habits of diving ducks in the Carolinas

Food habits analyses were conducted on 264 diving ducks (7 species) from North and South Carolina during the 1970'S. The Baltic clam (Macoma balthica) was the predominant food among canvasbacks (Aythya valisineria) from the Pamlico River area, whereas sago pondweed (Potamogeton pectinatus) predominated in birds from impoundments in North and South Carolina. Shoalgrass (Halodule beaudettei) formed 100% of the gullet food and 99% of the gizzard food in redheads (Aythya americana) from Pamlico Sound. Lesser scaup (Aythya affinis) in North Carolina had fed predominantly on mollusks (Mulinia lateralis and Rangia cuneata), whereas widgeon grass (Ruppia maritima) was the predominant food in birds from South Carolina. In North Carolina, ring-necked ducks (Aythya collaris) fed mainly on vegetation, and greater scaup (Aythya marila), bufflehead (Bucephala albeola), and ruddy ducks (Oxyura jamaicensis) fed mainly on Mulinia lateralis. Food habits data from this study when compared with historical food habits of these species indicate that most diving duck species were feeding more on invertebrates and less on submerged aquatic vegetation than in the past. North and South Carolina have a diverse food supply and appear to offer waterfowl adequate wintering habitat based on these food habits studies. Present trends in wintering habitat, however, could adversely affect diving duck populations in the future.

Proceedings of the Annual Conference of the Southe↗
USGS1997

Evaluation of a mallard HSI model for the Lower Mississippi Valley

We evaluated a habitat suitability (HSI) model developed for mallards ( Anas platyrhynchos ) wintering in the Lower Mississippi Valley by comparing mallard densities obtained from aerial surveys with habitat suitability indices derived from satellite imagery for 25, 256km 2 sampling units. Regression models that related mallard densities to habitat suitability indices accounted for only 29% of the variability in the data and the 95% confidence interval of predicted mallard densities included zero for most habitat suitability indices evaluated. Thus, we conclude that the published HSI model is a poor predictor of wintering mallard density in the Lower Mississippi Valley. We suggest model revision to allow users to remotely obtain model inputs for habitat characteristics at landscape scales. Further, we suggest the model be revised to consider yearly variation in habitat and flood conditions that better reflect the ability of an area to support wintering mallards.

Arkansas, Louisiana, Mississippi↗
USGS2000

Movements and survival of Bachman's Sparrows in response to prescribed summer burns in South Carolina

Prescribed winter burning is a common practice in longleaf pine (Pinus palustris) to manage for red-cockaded woodpeckers (Picoides borealis). The effect of these burns on non-target animals is not well studied. Bachman's sparrows (Aimophila aestivalis) were captured in predominantly longleaf pine stands to be burned and not to be burned at Carolina Sandhills National Wildlife Refuge (CSNWR) and the Savannah River Site (SRS), South Carolina. Sparrows were marked with radio-transmitters and monitored daily. Before burning, daily movements did not differ among sites within or among study areas. Additionally, daily movements did not differ by sex or time within the breeding season. After prescribed burning, daily movements were longer for sparrows in burned stands than in unburned stands. All marked sparrows dispersed 1-3 days after a stand was burned and never returned. We found no evidence that dispersing sparrows successfully breed elsewhere. Bachman's sparrow survival rates and reproductive output after burning were lowered. The juxtaposition of seemingly suitable Bachman's sparrow habitat in relation to burned stands influenced both the duration and length of dispersal movements. Managers need to consider the proximity of available habitats when developing burning plans when managing for Bachman's sparrows.

Proceedings of the Annual Conference of the Southe↗
USGS2000

Survival and reproductive biology of the Bachman's Sparrow

We estimated breeding season survival rates and nest success for Bachman's Sparrows at the Savannah River Site, South Carolina, using radio telemetry. The 1995 breeding season (2 May-9 Aug) survival rate was 0.905 (95% C. I. 0.779-1.03) with 2 mortalities out of 20 individuals. The 1996 breeding season (10 May-25 Jul) survival rate was 0.882 (95% C. I. 0.729-1.04) with 2 mortalities out of 18 individuals. No significant differences in survival rates were detected between years, sexes, or habitat types. The overall breeding season survival rate was 0.893 (95%, C. I. 0.794-0.992). Daily nest survival rate in 1995 was 0.952 (0.013 SE N=26) and 0.889 (0.027 SE N=15) in 1996. Daily nest survival was significantly greater during 1995, with only 1 of 15 nests fledging a single individual in 1996. Nests attempts initiated before 15 June (0.975 [0.012], N=15) had higher survival rates than later nest attempts (0.914 [0.029] N=11, C2=3.77, 1 df, P=0.05).

Proceedings of the Annual Conference of the Southe↗
USGS2007

Design and implementation of estimation-based monitoring programs for flora and fauna: A case study on the Cherokee National Forest

Science-based monitoring of biological resources is important for a greater understanding of ecological systems and for assessment of the target population using theoretic-based management approaches. When selecting variables to monitor, managers first need to carefully consider their objectives, the geographic and temporal scale at which they will operate, and the effort needed to implement the program. Generally, monitoring can be divided into two categories: index and inferential. Although index monitoring is usually easier to implement, analysis of index data requires strong assumptions about consistency in detection rates over time and space, and parameters are often biasednot accounting for detectability and spatial variation. In most cases, individuals are not always available for detection during sampling periods, and the entire area of interest cannot be sampled. Conversely, inferential monitoring is more rigorous because it is based on nearly unbiased estimators of spatial distribution. Thus, we recommend that detectability and spatial variation be considered for all monitoring programs that intend to make inferences about the target population or the area of interest. Application of these techniques is especially important for the monitoring of Threatened and Endangered (T&E) species because it is critical to determine if population size is increasing or decreasing with some level of certainty. Use of estimation-based methods and probability sampling will reduce many of the biases inherently associated with index data and provide meaningful information with respect to changes that occur in target populations. We incorporated inferential monitoring into protocols for T&E species spanning a wide range of taxa on the Cherokee National Forest in the Southern Appalachian Mountains. We review the various approaches employed for different taxa and discuss design issues, sampling strategies, data analysis, and the details of estimating detectability using site occupancy. These techniques provide a science-based approach for monitoring and can be of value to all resource managers responsible for management of T&E species.

Proceedings of the Annual Conference of the Southe↗
USGS2007

Using a novel micro-sampling technique to monitor the effects of methylmercury on the eggs of wild birds

Methylmercury is the predominant chemical form of mercury reported in the eggs of wild birds. The embryo is the life stage at which birds are most sensitive to methylmercury. Protective guidelines have been based largely on captive-breeding studies done with chickens (Gallus domesticus), mallards (Anas platyrhynchos), and ring-necked pheasants (Phasianus colchicus). Typically these studies are cost and time prohibitive. In the past, researchers have used either egg injections or the ?sample egg? technique to determine contaminant effects on bird eggs. Both techniques have their limitations. As an alternative to the above methods and because most of the methylmercury is found in the albumen we have developed a novel, less invasive technique, to micro-sample the albumen of eggs in the field. An albumen sample would be analyzed and then compared to the hatching success of that egg. Using the micro-sampling procedure, the egg is oriented with the blunt end up and the pointed end down. A vent hole is drilled at the top to relieve pressure. Approximately one third up from the bottom, a withdrawal site is drilled just until the inner shell membrane is exposed. A syringe with a 21 or 18 gauge needle is gently inserted just into the egg and approximately 200?300?l of albumen is removed. Almost concurrently this site and then the vent are sealed. Thus far we have experimented with both chicken and mallard eggs in the laboratory. We sampled chicken eggs at days 0 and 3 of incubation with a hatching success of 76% and 70%, respectively. Neither group was significantly different from control eggs (P=0.52, 0.54). Field studies are in progress using this technique in which birds are allowed to incubate their own eggs. We envision micro-sampling to be a tool that researchers and managers could use in the field to determine the effects of mercury or other contaminants in bird populations. Micro-sampling would reduce the impact on the sampled population and could be used to monitor sensitive species without impacting reproduction and recruitment.

Proceedings of the Annual Conference of the Southe↗
USGS2007

Effects of habitat change along Breeding Bird Survey routes in the central Appalachians on Cerulean Warbler population

The cerulean warbler (Dendroica cerulea) is one of the highest priority bird species in the eastern United States because populations have declined 4.3% annually during 1966?2005 based on Breeding Bird Survey (BBS) data. Habitat loss and fragmentation due to land use changes is thought to be one of the major factors contributing to the decline. BBS routes, the primary source for monitoring bird population trends, include 50 sampling stops every 0.8 km. Although data from BBS routes are extrapolated to determine regional trends in bird populations, it is important to understand the effects of habitat changes at the stop-level along BBS routes. Route-level analysis of habitat changes may mask important changes that are occurring at a smaller scale particularly for the cerulean warbler which displays several micro-scale habitat preferences. We are examining cerulean warbler habitat and population changes in its core breeding range of the Ohio Hills and Cumberland Plateau physiographic regions. We quantified land cover changes within 300 m of BBS routes in the core cerulean warbler breeding range of Ohio, West Virginia, and Kentucky by digitizing aerial photographs from two time periods: the 1980s and 2004. We also quantified land cover changes within 300 m of BBS routes with the National Land Cover Dataset (NLCD) from 1992 and 2001. The hand-digitized aerial photos will be compared with the NLCD to determine how similar the two methods are in quantifying land cover changes. We then compared stop-level land cover changes with stop level changes in cerulean warbler detections within the same time periods along the BBS routes. This will allow for a more detailed analysis of how well habitat changes along BBS routes reflect the changes in cerulean warbler populations.

Proceedings of the Annual Conference of the Southe↗