Wild Thing: A Duck of Our Own
Unlike other waterfowl, mottled ducks hang around Texas all year.
By Tucker Slack
Holler “Duck!” in a crowd and the folks who don’t drop down will likely get a mental image of a big, green-headed northern mallard. This comes as no surprise, given the bird’s colorful plumage, large size and abundance.
But down in the coastal country where mosquitoes reign, the mallard plays second fiddle to its obscure cousin, the mottled duck. While they are often referred to as black or summer mallards, mottled ducks are not really mallards at all, though they’re related.
The mottled duck (Anas fulvigula) is a year-round resident of our state, which is a unique situation among waterfowl. Mottled ducks generally spend their entire lives within about 60 miles of the Gulf of Mexico. Although they don’t participate in a traditional waterfowl migration, they do “migrate” along the coastline in search of optimal habitat conditions. They roam the coastal prairies and marshes of Texas and Louisiana and readily move between the two states.
These ducks are aptly named for their mottled brown appearance. A medium-size dabbling duck, only slightly smaller than mallards, they are dark brown with a lighter, buff-colored head and neck. The white underside of the mottled duck’s wing contrasts sharply with the dark bird and creates the illusion of silver wings when in flight.
Sexes are similar in appearance, with the major difference being bill coloration. Males have a yellowish-green to olive-colored bill, while females have an orange bill, accented with varying degrees of dark spots or splotches. The speculum, or colored part of the wing, is deep purple or bluish-green with a trailing edge of white.
Mottled ducks form pair bonds early, with more than three-quarters of the pair bonds formed by November. Males protect territories and hens as they nest on the ground; an average clutch size is nine eggs. Shortly after hatching, the ducklings are capable of leaving the nest but remain close to their mother for her protection.
TPWD has a long history studying these interesting denizens of our coastal marshes. These birds are as tough as they come, and they have overcome all obstacles in their way. They’ve had to deal with the alarming loss and conversion of coastal wetlands and the increased development of our coastline. They also must contend with the ingestion of lead and the threat of genetic swamping caused by hybridization with mallards.
Mottled ducks are now used as both a focal species for coastal habitat management efforts and a barometer to gauge the efficacy of current management practices. Through increased knowledge and effective management decisions, we can help to ensure a bright future for these unique and resilient birds.
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