The bird in the picture next to this post is a common myna (Acridotheres tristis), a native of southeastern Asia. The picture was taken by me on a Marine Biology field trip. Unfortunately, the trip wasn't to India, but to Florida--I snapped the picture in a Wal-Mart parking lot in Homestead. Florida cities have more birds than do many. Among the most common birds I saw were mynas, collared doves, rock pigeons, starlings, monk parakeets, cattle egrets, house sparrows, and house finches. If you know anything about birds, you know that not one of those species is native to Florida. In fact, Florida has had reports of nearly 200 species of exotic birds. Many of them are known only from a sighting or two, but others, including all of those listed above, have established breeding populations in Florida. Many of these birds are escaped pets--or worse, pets that have been released into the wild by owners tired of caring for them.
So what? Why should we care if a new bird or two is introduced into an area? Exotic birds compete with native birds for food and nesting space. For example, many authorities blame the decline in populations of native bluebirds on the fact that starlings and house sparrows outcompete them for the best nesting sites. Non-native birds may carry infections to which native birds lack any immunity. Non-native birds (such as parakeets and mynas) may act as agricultural pests. If they hybridize with native birds, non-native birds may dilute the gene pool of native birds.
The problem of introduced exotic species receives less attention than some other environmental maladies, but it has the potential to cause great harm to natural ecosystems, and to human activities. Everyone has heard stories of the problems caused by zebra mussels, fire ants, tiger mosquitoes, and killer bees; stories of more bizarre exotics (such as monitor lizards, pythons, and monkeys) are less well known. Despite this, people still seem to ignore the exotic pet trade. Apparently folks in Louisiana are all excited about the possibility of selling red-eared sliders as pets, even though there is the possibility of the turtles carrying salmonella, the turtles don't live very long in captivity (they have the potential to live 40 years in the wild), and no one has determined just what increased pet trade will do to the wild populations. No one seems to be worried about the effects released turtles might have in areas outside their natural range.
Here's the deal: We already have dogs and cats, and they do enough damage to the environment. There is absolutely no need for people to have more exotic pets. This isn't about the "rights" of pet owners--you DO NOT have the right to put your local ecosystem at risk. If you need a pet, shelters are full of cats and dogs that need you, too. Do everyone a favor--pass on the baby alligator. Skip the boa constrictor. Leave the parrots where they belong.