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Full-Text Articles in Ornithology
Flight Of The Sea Ducks, Paul A. Johnsgard
Flight Of The Sea Ducks, Paul A. Johnsgard
Papers in Ornithology
Their migration routes have been charted. Their breeding biology is known. Their eggs meat and feathers have long been used by man. But eiders at sea remain an enigma.
Nesting in colonies that can number hundreds of birds, the eiders are among the most conspicuous of tundra-breeding birds. Although female eiders are a study in grays and browns that match the arctic tundra, the males are most boldly patterned in black and white, with striking green head colors. When the nesting season ends, the birds disperse over the vastnesses of the northern oceans, out of range of most human observers. …
Seventy-Five Years Of Changes In Mallard-Black Duck Ratios In Eastern North America, Paul A. Johnsgard, Rose Disilvestro
Seventy-Five Years Of Changes In Mallard-Black Duck Ratios In Eastern North America, Paul A. Johnsgard, Rose Disilvestro
Papers in Ornithology
One of the most spectacular shifts in waterfowl dIstnbution patterns in North America is the degree to which Mallards (Anas platyrhynchos) have come to replace Black Ducks (Anas rubripes) as the dominant breeding and wintering species in the eastern half of the United States and Canada over the past several decades. The reasons for these changes in the actual and relative numbers of Mallards and Black Ducks are doubtless many and probably include such factors as man-induced habitat changes, game management practices such as artificial stocking programs and changing hunting regulations, and possibly even climatic trends, …