Thousands of Common Eider carcasses have been found floating in the cold water off Cape Cod or rotting on beaches. Many more of the birds have been found emaciated, exhausted, and suffering, often near death. In recent years, a mysterious virus has taken a mounting toll on the region’s common eiders, a normally bulky sea duck considered a barometer for the health of Cape Cod Bay.
Determining appropriate statistical distributions for modeling animal count data is important for accurate estimation of abundance,distribution,and trends.In the case of
seaducks along the U.S.Atlantic coast,managers want to estimate local and regional abundance to detect and track population declines, to define
Abstract
This paper presents a simple stochastic model of the dynamics of waterfowl aggregation, investigates model fit, and considers
variance in the model’s parameter estimators. The model, a marked-point process with four parameters, describes a behavioral
process defined by the movements of animal groups. My approach provides new methods to explore animal social behavior. I
illustrate the fit of the model to field observations of 39 aggregations observed when they were not at equilibrium and outline a
Although monitoring data for sea ducks (Tribe Mergini) are limited, current evidence suggests that four of the most common species wintering along the eastern coast of the United States—long-tailed duck Clangula hyemalis, white-winged scoter Melanitta fusca, surf scoter Melanitta perspicillata, and black scoter Melanitta americana—may be declining, while the status of American common eider Somateria mollissima dresseri is uncertain.
Informed management of waterfowl (or any animal population), requires management goals and objectives, the ability to implement management actions, periodic information about population and goal related variables, and knowledge of effects of management actions on populations and goal related variables. In North American international Treaties mandate a primary objective of protecting migratory bird populations, with a secondary objective of providing hunting opportunity in a manner compatible with such protection.
The world distribution of Barrow’s Goldeneye (Bucephala islandica) consists of three
separate populations: 150 000 to 200 000 birds in western North America (Eadie et al 2000),
a resident population of 2000 in Iceland (Gardarsson 1978), and approximately 4500 birds in
eastern North America (Savard and Dupuis 1999; Robert et al 2000a). The breeding range is
discontinuous in North America and is largely restricted to northwestern North America, where
more than 90% of the world’s population breeds (del Hoyo et al 1992). Little is known of the
Studies of declining populations of sea ducks have focused mainly on bottom–up processes with little emphasis
Concerns about apparent declines in Steller's eider (Kertell 1991) and other sea duck populations
prompted personnel of the Kodiak National Wildlife Refuge to initiate an annual winter aerial
survey to assess and monitor sea duck populations.The fourth Kodiak aerial Steller's eider winter survey was flown from 29 January to 2 February
2001, covering most of the eastern coastal portion of the Kodiak Archipelago. The survey design
consisted of a single flight parallel to the shoreline between 200 and 400 meters offshore, with s-
Since 1992, U.S. Fish and Wildlife Service, Migratory Bird Management has flown a spring
aerial survey in southwest Alaska to monitor trends in the Pacific population of Steller’s eiders
and improve understanding of habitat use and timing of spring migration. Due to constraints with
the traditional spring survey, we sought to test
the feasibility of an alternative monitoring approach using photography of fall molting flocks
along the Alaska Peninsula. Our goal was to determine whether different survey timing and methods
The majority of the Pacific population of Steller's eiders migrates along the Bristol Bay coast of the
Alaska Peninsula in the spring, crosses Bristol Bay toward Cape Pierce, then continues northward
along the Bering Sea coast. Most then cross the Bering Strait to their breeding grounds in Siberia, with
a smaller number continuing north to the Alaska North Slope to breed (U. S. Fish and Wildlife Service
2002, Gill et al. 1978). During migration the eiders linger to feed at the mouths of lagoons and other