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Geology topics

E.J.R. Lohnes

Publications and source records attributed to E.J.R. Lohnes.

8 recordsLinked to original sources
USGS2006

Characterization of breeding habitats for black and surf scoters in the eastern boreal forest and subarctic regions of Canada

We analyzed characteristics of wetland habitats used by breeding black scoters (Melanitta nigra) and surf scoters (M. perspicillata) in the eastern boreal forest and subarctic regions of Canada based on satellite telemetry data collected in the spring and summer. During 2002 and 2004, nine black scoters (four males, five females) were tracked to breeding areas in Quebec, Manitoba, and Northwest Territories. In addition, in 2001?04, seven surf scoters (three males, four females) were tracked to breeding areas in Labrador, Quebec, Northwest Territories, and Nunavut. Based on satellite telemetry data, locations of black and surf scoters in breeding areas were not significantly different in regard to latitude and longitude. Presumed breeding areas were manually plotted on topographic maps and percent cover type and water were estimated. Breeding habitat of black scoters was significantly different than that for surf scoters, with black scoters mainly using open (tundra) areas (44%) and surf scoters using mainly forest areas (66%). Surf scoters presumed breeding areas were at significantly higher elevations than areas used by black scoters. Some breeding areas were associated with islands, but the role of islands for breeding areas is equivocal. These results aid in the identification of potentially critical breeding areas and provide a baseline classification of breeding habitats used by these two species.

Book chapter↗
USGS2005

Habitats used by black and surf scoters in eastern North America as determined by satellite radio telemetry

Satellite radio telemetry was used to determine the movements and habitats of black scoters (Melanitta nigra) and surf scoters (Melanitta perspicillata) in eastern North America. A total of 21 surf scoters were instrumented during five years (2001-05) and 32 black scoters were instrumented during three years (2002-04) with implanted PTT 100 satellite transmitters (39 g) with external antenna. Nesting habitat of black scoters was more open than surf scoters (44% vs. 11%), whereas nesting habitat for surf scoters was located in more forested areas (66% vs. 20%). Locations of black scoters in breeding areas on average were at significantly higher latitude and lower elevations than sites used by surf scoters. Satellite telemetry determined that James Bay was the major molting area for male black and surf scoters, although some males molted along the coast of Labrador-Newfoundland. Black scoters instrumented on the Restigouche River, which is a major staging area, were widely distributed along the Atlantic Coast from Cape Cod to Georgia during winter. Major wintering areas for black scoters were Cape Cod (Martha's Vineyard and Nantucket Island), Long Island, and New Jersey. In these northern marine wintering areas, black scoters were located farther from shore (4.2 km) and in deeper water (8.3 m) than black scoters in more southern estuarine areas, where distance from shore was 3.1 km and water depth was 5.2 m. Surf scoters instrumented in Chesapeake Bay in late winter showed a strong tendency to return to the Bay the following winter after they had migrated to and from breeding areas. In Chesapeake Bay, black scoters and surf scoters were located mostly in mesohaline areas that had similar water depths (5.1 m vs. 7.5 m) and distances from shore (3.0 km vs. 2.9 km). Distance from shore and depth of water increased over time during the winter for both species. Updated information from the ARGOS Systems aboard the NOAA satellites on scoter movements was made accessible on the Patuxent Website.

Book chapter↗
USGS2005

The Atlantic Seaduck Project: Medical Aspects

Some populations of seaducks, especially scoters along the Atlantic Coast, have been declining over recent decades. A joint US-Canadian tearn has been working to capture and surgically implant satellite radio transmitters in these ducks. Black scoters (Melanitta nigra) captured on the Restigouche River in New Brunswick, Canada and surf scoters (M. perspicilata) captured on Chesapeake Bay, Maryland, USA have been tracked by the use of Argos/NOAA polar orbiting operational environmental satellites to their breeding and molting areas and back south to their wintering ranges. Successful capture techniques included night-lighting and a capture net gun. A captive colony of seaducks has been maintained for feeding habits and nutritional studies. Veterinary medicine has played a key role in the surgical implantation of the satellite transmitters and in developing heath procedures for the captive seaduck colony.

Conference Paper↗
USGS2004

Food habits of mute swans in the Chesapeake Bay

Unlike the tundra swan (Cygnus columbianus) that migrate to the Bay for the winter, the mute swan (Cygnus olor) is a year long resident and therefore has raised concerns among research managers over reports of conflicts with nesting native water birds and the consumption of submerged aquatic vegetation (SAV). Although data on the reduction of SAV by nesting mute swans and their offspring during the spring and summer are limited, food-habits data show that mute swans rely heavily on SAV during these months. Analyses of the gullet and gizzard of mute swans indicate that widgeon grass (Ruppia maritima) and eelgrass (Zostera marina) were the most important food items to mute swans during the winter and spring. Other organisms were eaten by mute swans, but represent small percentages of food. Corn (Zea mays) fed to the swans by Bay residents in late winter probably supplements their limited vegetative food resources at that time of year.

Book chapter↗
USGS2004

The mute swan, its status, behavior, and history in the U. K

For many years the mute swan has been considered a royal bird. It is a prominent resident throughout the United Kingdom (U.K.), often found on the inland waterways. Some people consider it to be a nonmigratory native bird because it doesn't tend to move large distances and doesn't often venture far from freshwater. A mute swan may often live out its life cycle in the same river valley in which it hatched. Over the last 30-40 years, a large amount of research has been carried out on their life cycle, behavior, and mortality caused by such factors as lead poisoning from fishing weights. Throughout the U.K., there are a number of areas where mute swans may be found in large numbers, including (1) the River Thames (which passes through London), (2) Slimbridge Wetlands Center, (3) Berwick-upon- Tweed (the second largest mute swan colony in Britain), and (4) Abbotsbury Swannery (the worlds only managed swan colony). This last site is a truly unique area, and each year it often has over 150 nesting pairs producing between 2-12 eggs per nest. The management is minimal, and the site is ideal for their requirements because it is close to a number of freshwater sources, and has good nesting sites and large quantities of eelgrass Zostera marina and widgeon grass Ruppia maritima, their preferred food sources. The Swannery is located on the south coast of England at the western end of the Fleet Lagoon, a micro-tidal estuary, which borders the English Channel.

Book chapter↗
USGS2000

Establishment of warm season grasses with and without the use of compost soil amendments

Two compost materials (COMPRO and LEAFGRO) were evaluated as soil amendments to enhance wildlife habitats, while maintaining optimal floral and faunal biodiversity. Special emphasis was placed on the role of compost in the establishment and retention of native warm season grasses (Andropogon gerardi, Schizachyrium scoparium, and Sorghastrum nutans). This study was conducted at two sites that were degraded by previous military and farming operations. Sites were plowed twice in 1996 and then a one inch layer of COMPRO or LEAFGRO was applied with a modified manure spreader and disked into the soil to a depth of 3 inches. Vegetation sampling was conducted in 1996, 1997, 1998, and 1999. Initially the greatest vegetation cover occurred in plots treated with LEAFGRO. Plots treated with COMPRO had less vegetation cover than both types of controls plots (with and without warmseason grasses). The reduced plant growth in the plots treated with COMPRO may have been related to the much higher soil pH of these plots on both sites. In subsequent years, amounts of warm season grasses increased, however, in general there was more cover of warm season grasses in plots that did not receive compost than those that did receive compost. Sorghastrum nutans was more abundant on the sites than either of the other two species of warm season grasses. Invertebrate and mammal data collected for three years indicated that there was not more faunal activity in the plots treated with LEAFGRO or COMPRO compost soil amendments. Results indicate that compost amendments did not improve establishment of warm season grasses and the resultant faunal diversity or abundance.

Book chapter↗