Many species such as the spot-breasted oriole became established simply because Florida's resources are accommodating. In 1973, Owre (1973) stated that southeastern Florida is preconditioned for exotic invasion because of its many uninhabited shallow-water habitats that suit many species for breeding. Even before 1973, the flora of southeastern Florida contained elements of the world's tropics; therefore, almost every exotic, tropical bird finds characteristics of Florida that are similar to its native land (Owre 1973).
Crider (1968) pointed out that the abundance of canals in tropical southern Florida would probably provide suitable habitat for non-native waterfowl introduced from similar habitat, and that if a waterfowl species suitable for hunting and eating was found its introduction would be advantageous. This and Brookfield and Griswold's (1956) statement clearly illustrate the public's view of the establishment of nonindigenous species. Cruickshank (1980) discussed the birds that exist in southern Florida, and Neville (1990) listed the exotic birds in southern Florida. This rapid establishment may also be seen in the number of established nonindigenous bird species. Del Hoyo (1992) stated that 11 exotic bird species have self-sustaining wild populations in the state since the implementation of agriculture (Table 9).
Although there are several early records of human transportation of birds from one area to another, not much is known about the exact time deliberate releases became commonplace practice (Long 1989). Several reasons people list for introducing birds are aesthetics, food, hunting and sport, controlling pests, escapees, aviculture, and accidental introductions (Long 1989). Some releases of waterfowl are examples of birds that were introduced for aesthetic reasons. Birds such as the mute swan (Cygnus olor) gave social status to those who released them on their lands (Long 1989). However, the successful introduction of nonindigenous birds has caused problems such as competition for resources, the introduction of diseases and parasites, and damage to agricultural crops in many areas of the world (Long 1989). For example, the house sparrow (Passer domesticus) was introduced to control dropworm (Oiketicus spp.) in the United States but has been accused of spreading the cestodes and nematodes in poultry (Long 1989). Other diseases that were introduced by caged bird species such as parrots are positive-Newcastle disease and influenza Type-A virus from caged birds imported from southeastern Asia into North America (Long 1989).
Muscovy Duck (Cairina moschata). This species, sometimes called the royal duck (Pato real), is a native of neotropical lowlands from Mexico south to Central and South America. The first release of this species in Florida was made in 1967 on Fisheating Creek in Glades County where the Florida Game and Fresh Water Fish Commission and the U. S. Bureau of Sport Fisheries and Wildlife released approximately 24 of 100 muscovy ducks that had been imported from Central and South America (Hutt 1967; Crider 1968). After the ducks arrived and were quarantined at the Miami International Airport Port of Entry, a study was conducted from July 1966 through June 1967 to determine the feasibility of the establishment of wild populations of this species in Florida. The ducks were tested on the Fisheating Creek Refuge, in the Guano River Wildlife Management Area, in the Camp Blanding Wildlife Management Area, in the Tallahassee Research Area, and in the Caribbean Gardens. The study revealed that this duck could survive in those areas. Although the attempted establishment of the birds was probably unsuccessful, the fates of these individuals are unknown. The population that is established in Florida was probably established from escaped or released domestic stock that seems to have hybridized with the mallard duck (Anas platyrhynchos) and other waterfowl (Robertson and Woolfenden 1992). At present, muscovy ducks are the most commonly seen waterfowl species in the waters of suburban Florida. Although muscovys ducks fight among themselves, they mingle with other ducks.
Mute Swan (Cygnus olor). This species is indigenous to Europe where it was domesticated by the nobility and by the wealthy (Esch 1993). This swan decorated the homes of the rich and was immortalized in the literature by Yeats and Hans Christian Anderson and by music by Tchaikovsky. Most wild mute swans in the Atlantic Flyway (a corridor from Quebec, Canada, to Florida) are related to captive swans that were released in southeastern New York around 1910 (Esch 1993). The number of wild mute swans has increased by 3,000 since 1987 and now exceeds 8,000 in the Atlantic Flyway, (Esch 1993). Since the 1960's, this species has been reported in Bay, Brevard, Dade, De Soto, Hillsborough, Martin, Palm Beach, and Polk counties (Robertson and Woolfenden 1992). The mute swan is not established in Florida.
Although it can be aggressive and even dangerous to other birds in its territory, the mute swan is one of the most popular captive birds. It eats large amounts of water plants; aggressively defends its nesting area (as large as 4 ha) against ducks, geese, and canoeists; and fouls beaches and reservoirs with cigar-size droppings (Esch 1993). In New York, mute swans have foiled attempts to restore wetlands along the Hudson River. These birds eat new plants as quickly as they are planted (Esch 1993). Chuck Keene, a naturalist at the Museum of the Hudson Highlands, New York, stated that although the mute swans are aesthetically pleasing, they reduce the river's ability to sustain the Atlantic fishery, native waterfowl, and native muskrats (Esch 1993). Eradication has centered on shaking swan eggs to kill the developing embryo, shooting the swans, or trapping and sending the swans to zoos or to private ponds; however, many people do not want the swans killed because they are aesthetically pleasing.
Black Swan (Cygnus atratus). The black swan is a native to Australia and less aggressive than the mute swan. Black swans have been reported in Hillsborough, Monroe, Orange, Palm Beach, and Polk counties in 1961 and in the 1980's (Robertson and Woolfenden 1992). Although this species is not established, populations may increase, and control measures such as hunting and the harvesting of eggs may become necessary.
Greater Flamingo (Phoenicopterus ruber). Until at least 1902, several thousand flamingos migrated annually (June-February, timing variable) from the West Indies (possibly northwestern Andros, Bahamas) into the Florida Bay to molt (Robertson and Wolfenden 1992). In January 1931, a flock of flamingos was shipped to Miami from Cuba and released on the Hialeah Race Course (Allen 1954, 1956). The birds were not pinioned and flew away 1 day after the release. Although wild flamingos were often reported in Florida in the 1930's, breeding colonies were never established. However, in 1942, another flock was pinioned and introduced, and a yearly breeding colony of 65 birds was established (Terres 1980). Because of their resistance to harsh conditions such as high levels of chlorides, sodium carbonate, sulfates, and fluoride, and low ambient temperatures of 68 , greater flamingos are used as tourist attractions in areas that other species cannot tolerate.
Because of the remoteness of their habitats in the wild and their diet of algae and invertebrates, flamingos rarely conflict with human economic interests (del Hoyo 1992). The only reported conflict arose when humans moved the Camargue rice fields of Florida into the flamingo's habitat in 1978 and the birds crushed the rice plants during foraging at night (del Hoyo 1992).
Scarlet Ibis (Eudocimus ruber). The natural distribution and breeding range of the scarlet ibis is confined to northern South America. Although 17 birds fledged from 24 scarlet ibis eggs that were introduced into the nests of white ibises (Guara alba) in the rookery of Greynolds Park, this species is not established in Florida (Bondy 1962). Birds from Dade County have interbred with resident white ibis populations (Quincy 1977). Birds often escaped from the Bush Gardens in Tampa (Robertson 1962). Scarlet ibises outside the species' breeding range are usually individuals that were transferred by storms or by humans (Quincy 1977). This species is expected to disappear soon because it currently exists in an urban area where frequent disturbances preclude breeding. Human encroachment, pollution, predation by cats, and nest competition also preclude establishment (Quincy 1977).
White-cheeked pintail (Anas bahamensis). At one time, the Florida Game and Freshwater Fish Commission desired to introduce the white-cheeked pintail (also known as Bahama pintail and Bahama duck) in Florida to alleviate hunting pressure on the mottled duck (Anas fulvigula) that is native to Florida. This introduction was not made because the Bahamian government would not trade white-tailed deer (Odocoileus virginianus) for this species for fear of introducing diseases of the Florida population of white-tailed deer into the deer populations on their islands (Evans 1960). The white-cheeked pintail was probably the most promising species for introduction and establishment because its northernmost native range was only 80 km from the Florida mainland, indicating a strong probability of survival in Florida (Evans 1960). Pough (1951) indicated that in Florida the white-cheeked pintail was historically hunted near Cape Canaveral and that it may have naturally occurred in Florida as a rare vagrant (Robertson and Woolfenden 1992). Although the Florida Game and Freshwater Fish Commission viewed the white-cheeked pintail as an excellent buffer species for the mottled duck, Sincock (1957) pointed out the possibility of a population explosion of the white-cheeked pintail if it were established. The white-cheeked pintail is not only a prolific breeder but vulnerable to excessive hunting (Evans 1960). Odum (1954) stated that management of an established native species with recreational value such as the mottled duck is wiser than the introduction of a nonindigenous species. Therefore, in 1960, Evans (1960) concluded that the white-cheeked pintail should not be introduced in Florida.
