Thanks to Google.com, I found a few links to additional information on the Muscovy Duck and it's impact on Florida...
Deltona newspaper article (March, 2001).

Univ of Florida Extension Service article.

Biscayne Bay campus sign (with pix).

Seems as if the Muscovy was not ever native to Florida, and is therefor considered a domestic pest when it is allowed to multiply and begins to frequent suburban yards and waterways.

Many Floridians must look upon the Muscovy in the same way that some New Yorkers view the common Pigeon.