Relatively few non-native bird species have become established in Florida (Hardin 2007), as only about 5% of the roughly 200 non-native species introduced have succeeded at becoming established (Avery 2007). The purple swamphen (Porphyrio porphyrio), a recent introduction to Florida, was judged to merit eradication by a consensus of land management agencies based on its increasing population and range expansion, its potential impact to native species, and the potential for an eradication effort to succeed (Ferriter et al. 2008, Hardin 2007). This large rail species is native to Europe, Africa, Asia and Australia. It also is native to American Samoa, a factor potentially complicating its control in Florida if eradication efforts were delayed (Ferriter et al. 2008). Because it is native to American Samoa, the purple swamphen is being considered for inclusion to the Migratory Bird Treaty Act (MTBA). However, the MTBA provides protection for a species throughout all U.S. holdings and historically has not made geographic distinctions within the U.S., which could protect purple swamphens from removal in Florida in the future. This factor increased the urgency to move on the Florida population.
The species was first observed in the wild in urban southeast Florida in 1996, where the population resulted from escapes from a local aviculturist or escaped from the Miami Metrozoo in 1992 as a result of Hurricane Andrew (Avery 2007, Ferriter 2008, Hardin 2007). As the population increased to over 200 birds, it still remained only in developed areas, but by 2006 it had expanded its range to Everglades Conservation Areas and has been reported as far north as Lake Okeechobee (Hardin 2007). Efforts to eliminate the purple swamphen were prompted by its ecological similarity to the native common moorhen (Gallinula chloropus) and purple gallinule (Porphyrula martinica) and the looming potential for it to be protected by the MTBA (Ferriter 2008, Hardin 2007).
Purple swamphen control was initiated in 2006 in a cooperative effort among biologists with the South Florida Water Management District (SFWMD), the U.S. Fish and Wildlife Service (USFWS), and the Florida Fish and Wildlife Conservation Commission (FWC). Over 800 birds were located and removed during October 2006-August 2007 (Clary 2007). Efforts are scheduled to continue to remove the remainder of the introduced population. At the least, potential impact to native wildlife and vegetation can be minimized, or at the best, the species will be eradicated from Florida (Avery 2007, Hardin 2007).
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