Mallards in Florida during the spring and summer
originated from captive-reared stock. We consider these
semi-domestic mallards, which are proliferating, a serious threat
to Florida's wild waterfowl. Numerous diseases, including duck
plague and fowl cholera, have been linked specifically to domestic
or captive-raised waterfowl, and are easily transmissible to wild
ducks. The potential for such an outbreak is a biological
concern. Another significant threat of mallards is the genetic
introgression of mallards into Florida's mottled duck population
(see hybridization below).
Dealing with nuisance mallards is more complicated
than controlling muscovies. If mallards are obvious
hybrids with muscovies or other domestic ducks (see photo below),
then no federal or state wildlife laws protect them from capture or
direct population control. These hybrids may be moved to a captive
situation where they would not come into contact with wild birds,
or humanely euthanized as a last resort. If, on the other hand, the
mallards have plumage similar to true, wild-strain mallards, and
the birds are not marked as captive reared (generally, either
marked with a clipped hind toe or a seamless metal leg band), then
the birds are protected under federal migratory bird regulations.
Destroying eggs or directly controlling populations requires
appropriate mallard control permits.
Feral mallards are mating with mottled ducks, producing a hybrid
offspring. State biologists are observing more and more mixed
flocks and mixed pairs in the wild and these. These hybrid
offspring are fertile, which further compounds the problem. Every
mallard released in Florida can potentially contribute to the
hybridization problem and the result is that fewer and fewer
pure-bred Florida mottled ducks are left each year. The complete
hybridization could result in the extinction of the Florida mottled
Hybridization - The problem and what you
can do to help.
Mottled duck profile page.