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
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
Estimates of range-wide abundance, harvest, and harvest rate are fundamental for sound inferences about the role of exploitation in the dynamics of free-ranging wildlife populations, but reliability of existing survey methods for abundance estimation is rarely assessed using alternative approaches. North American mallard populations have been surveyed each spring since 1955 using internationally coordinated aerial surveys, but population size can also be estimated with Lincoln's method using banding and harvest data.
The following briefing material has been assembled for use by The Pacific Flyway Council, Pacific Flyway Study Committee & Cooperators and by U. S. Fish and Wildlife Service
personnel in formulating recommendations for the 2013-2014 waterfowl hunting seasons. This collection of
harvest, population, and hunter data can also serve as a desk-top reference for providing responses to inquiries
from agency personnel, the media, and public.
Knowledge of ecological factors that influence birth, death, immigration, and emigration provide
insight into natural selection and population dynamics. Populations of Pacific common eiders
(Somateria mollissima v-nigrum) on the Yukon-Kuskokwim Delta (YKD) in western Alaska declined by
50-90% from 1957 to 1992 and then stabilized at reduced numbers from the early 1990’s to the
present. This study investigates the primary underlying processes affecting population dynamics of
We estimated the summer and winter abundance of marine birds in Prince William
Sound, Alaska, following the 1989 Exxon Valdez oil spill, examined changes in population size
between pre-spill and post-spill surveys, and compared pre- to post-oil spill population trends in
the oiled zone of the Sound relative to trends in the unoiled zone.
Ninety-nine species of birds were observed on surveys. Not all species were equally vulnerable to
the oil spill because of the seasonal and geographic distribution. Estimated populations of 15 to
The goal of this project was to determine whether the Exxon Valdez oil spill had measurable sublethal effects on six species of migratory and resident seaducks in Prince William Sound and the Kodiak Archipelago. The six seaduck species were harlequin ducks, Barrow's and common goldeneyes, and surf, black, and white-winged scoters. The harlequin ducks are both resident in and winter migrants to the oil spill area. The other species do not breed in the oil spill area but are winter migrants.