Resources related to Abundance

Reproductive ecology and habitat use of Pacific Black Scoters (Melanitta nigra americana) nesting on the Yukon-Kuskokwim Delta, Alaska

Abstract.—Abundance indices of Black Scoters (Melanitta nigra americana) breeding in Alaska indicate a long- term population decline without obvious cause(s). However, few life history data are available for the species in North America. In 2001-2004, information was collected on nesting habitat and reproductive parameters (i.e. com- ponents of productivity) from a population of Black Scoters nesting on the Yukon-Kuskokwim Delta, Alaska. A total of 157 nests were found over four years.

Energy-Based Carrying Capacities of Bufflehead Bucephala albeola Wintering Habitats

We present a model for calculating energy-based carrying capacities for bufflehead (Bucephala albeola), a small North American sea duck wintering in coastal and estuarine habitats. Our model uses estimates of the seasonal energy expenditures that incorporate site-specific energetic costs of thermoregulation, along with available prey energy densities to calculate carrying capacities in numbers of birds per winter. The model was used to calculate carrying capacities under several foraging scenarios for bufflehead wintering at three urban and three rural sites in the coastal northeast U.S.

To fly or not to fly: high flight costs in a large sea duck do not imply an expensive lifestyle

A perennial question in ornithology is whether flight has evolved mostly to facilitate access to food or as an anti-predator strategy. However, flight is an expensive mode of locomotion and species using flight regularly are associated with an expensive lifestyle. Using heart rate (HR) data loggers implanted in 13 female common eiders (Somateria mollissima), our objective was to test the hypothesis that a high level of flight activity increases their energy budget.

Influence of annual variation in food supply on abundance of wintering common eiders Somateria mollissima

We investigated how the annual variation in the abundance of wintering common eiders
Somateria mollissima was related to the abundance of benthos over 4 yr. The study was conducted at
2 sites, Tunø Knob and Ringebjerg Sand, Denmark, from 1994 to 1998. Benthos was sampled along
permanent transects in November, and common eiders counted and localized from observation
towers during the winter. The benthic community was dominated by the blue mussel Mytilus edulis,

Assessing the impact of the Tunø Knob wind park on sea ducks: the influence of food resources

This study deals with the influence of benthos abundance when
assessing the potential impact of a small wind park on wintering sea
ducks. Using the Before-After-Control-Impact design, it was suggested
in a recent study (Guillemette et al. 1998) that the wind park provoked
a decline in the abundance and a change in the distribution of common
eiders Somateria mollissima and common scoters Melanitta nigra .
However, the observed decline in sea duck abundance occurred concomitantly
with a decline of benthic food supplies. We measured concomitant

The role of herring spawning grounds as Marine Protected Areas for scoters (Melanitta spp.) in the Puget Sound-Georgia Basin

Scoters and other waterbirds congregate in dramatic numbers to consume Pacific herring (Clupea pallasi) spawn each spring along most of the Pacific Coast. Spawning occurs later at progressively higher latitudes, and may thus provide critical staging areas for scoters acquiring reserves as they migrate north to breed.

Effects of temperature and mussel size on intertidal mussel bed infaunal communities: implications for climate change and biodiversity.

While mussel beds can withstand the changing tides, global climate change may cause damage to these diverse ecosystems. As the amount of carbon dioxide in the air increases, so does the amount of carbon dioxide dissolved in seawater. The resulting acidification changes the basic chemistry of the oceans and decreases the growth rate of organisms which rely on dissolved calcium carbonate to build their shells.

Relative roles of eelgrass vs. hard-mixed substrates as habitatfor scoters (Melanitta spp.) in Puget Sound

Scoters ( Melanitta spp. ) are sea ducks that breed in freshwater wetlands of Canada and Alaska and winter in estuaries and bays on the Pacific and Atlantic coasts (Fig. 1). As with most sea ducks, scoter populations have declined in many parts of their Pacific Coast ranges. Three species of scoter can be found in wintering in Puget Sound, the common scoter ( Melanitta nigra ), the white-winged scoter ( Melanitta deglandi ) and the surf scoter ( Melanitta perspicillata ). The combined population of all three scoters declined by 57% between 1978-79 and 1992-99.

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