Red-breasted Merganser

Red-breasted Merganser by Tom Finnie
© Tom Finnie
Mergus serrator
This particular bes-scie, as all mergansers are called in southern Louisiana, is mainly a bird of the coastal waterways, moderately common from the last part of October until the end of April, with a few remaining until as late as June 22. It is especially numerous in Cameron Parish, in Barataria and Vermilion bays, in Lake Borgne, and in Chandeleur Sound. It has probably always been much less common on inland freshwater lakes, but this seems to have been particularly true since 1935. I counted over 100 individuals of this species on False River on December 13, 1934, but in more recent years I have seen it there only occasionally and in very small numbers. In terms of absolute frequency of reports from the interior, it runs a close second to Common Merganser, and it too has been found as far north in the state as Caddo Lake; but a much smaller proportionate number of its sightings have been in noncoastal settings.
The male Red-breasted Merganser has a conspicuously crested, green-glossed blackish head that is separated from the dull reddish breast by a white collar. This combination of characters, together with its brownish sides, really distinguishes it from the male Common Merganser, which is green headed but immaculate white or pale pinkish white on the entire breast and along the sides. The females of the two species are, however, much more difficult to separate. In each the head is reddish, but the two differ in the prominence of the white on the throat and the base of the neck. In the Common Merganser the white throat stands out in sharp contrast to the reddish areas of the head and neck. In the present species the reddish part of the head and neck blend with the white of the throat and foreneck.
--George H. Lowery, Jr., 1974, Louisiana Birds

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