by Jack Winter

Created on: June 12, 2009

The mottled duck (Anas fulvigula maculosa) is a large duck with a mottled fuscous-brown plumage (Bellrose 1980). The sexual dimorphism of the mottled duck is hard to distinguish because both sexes have nearly the same coloration the exception is that the female has lighter plumage than that of the male. One perceivable characteristic betwixt the female and male is the coloration of the upper mandible: the color in the male mandible varies between olive to yellow, whereas in females the coloration varies from orange to olive with erratic black or brown spots. Another difference between male and female mottled ducks is that the legs of males are bright orange and the females are dull orange in color (Moorman and Gray 1994).

The mottled duck is found in southern Florida and along the Gulf Coast of Louisiana and Texas and down to the Alvarado Lagoon near Veracruz (Bellrose 1980). Its primary habitat is coastal marshes and lagoons (Knopf 1995). The mottled duck is of the dabbling duck variety preferring the freshwater prairie ponds of Florida and the turbid marsh ponds along the Golf Cost (Corman and Gray 1994). The range of a single mottled duck is natal in that it rarely, if ever, travels farther than a couple hundred miles of its birth site (Bellrose 1980). The abundance of the mottled ducks are performed through an annual systematic population survey in Florida only, other parts of the ducks range are not gathered. This is problematic since mottled ducks range near their natal site, which includes the Gulf Coast of Louisiana and Texas as well as far south as Veracruz. In 1991 the spring and fall survey estimated around 28000 and 56000 birds respectively in Florida alone (Moorman and Gray 1994). Some concern about total abundance has arisen due to conflicting reports; in areas where mottled ducks are hunted bag limits are more restrictive (Elsey and Trosclair and Linscombe 2004).

It is unclear as to the evolutionary divergence of the mottled duck from that of the Mallard; however, mottled ducks and Mallards have been known to hybridize (Moorman and Gray 1994). The apparent reason for the hybridization is because the mottled ducks coloration is similar to a female mallard. The mottled duck mating rituals, which are similar to those of the mallard, lead one to believe that the infrequency of crossbreeding with the mallard can be summed up by its "pair formation; which begins as early as August, much earlier than other ducks;" (Moorman and Gray 1994).

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