I am the senior author of the life history of the Monk Parakeet, published in 1998 in the Birds of North America series (Vol. 9 No. 322). (This series is supported in part by the American Ornithologists' Union, Cornell Laboratory of Ornithology, and the Academy of Natural Sciences.) When reading early scientific accounts of the Monk Parakeet's arrival in the United States, it was clear that the species was rarely treated objectively.

The anti-parakeet feelings stemmed from fears that the Monk, a native of South America, would spread across the country like Carp, Kudzu, and other invasive, non-native species. However, prudent scientific caution often crossed the line into "guilty until proven innocent."   For example, the following came from a piece about the parakeets that appeared in a 1973 Journal of Agriculture of University of Puerto Rico,

the phrase 'further research is needed' must never become a euphemism for failure to act.

This sentiment reminds me of the humorous line, "Don't bother me with the facts, my mind is made up."

Interestingly, those early accounts also contained the reasons why the Monk Parakeet has not spread across the continent during the past 30 years, as originally feared. Noted ornithologist John Bull, who chronicled the parakeet's arrival in New York during the early 1970s stated, correctly, that the Monk was either "strictly" or "virtually sedentary."

Be that as it may, in a 1971 leaflet published by what is now the U.S. Fish and Wildlife Service, Gardiner Bump, who consulted John Bull, wrote,

If established here [New York and New Jersey], there is every reason to expect that it will gradually extend its range southwards to Florida and westwards to include the Southwest and the West Coast.

In fact, with the knowledge at hand then, there was very little reason to expect such a spread. The passage of time has confirmed John Bull's sedentary characterization of the species.

You see, because of the successful invasions of a few exotic species, such as Starlings, House Sparrows, and Pigeons, some biologists often think that ALL non-native species, such as the Monk Parakeet, are chomping at the bit to invade and exploit North America.

More often than not, exotics that are accidentally released on the continent disappear quickly and without notice. Also, many of these early "success" stories – unlike the Monk Parakeet, which was introduced for a captive existence – weren't accidentally released, but were deliberately introduced into the North American ecosystem.

Starlings, for instance, had been unsuccessfully released in New Jersey, Massachusetts, Ohio, Oregon, and Quebec before they were finally, and successfully, introduced in New York in 1890. By 1980, according to one authority, there had been, roughly, 120 species of birds released in the United States. This list includes transplants and the reintroduction of rare natives, such as the Peregrine Falcon. Of these, about a third took hold, most of these only to be locally established. Very few became a widespread nuisance.

Unfortunately, some of today's ornithologists continue to ignore the facts and maintain that the parakeet is a looming threat, having still to prove its innocence. From his 1989 book, The Birds of Illinois, H. David Bohlen writes of the Monk Parakeet,

. . . their maliciousness toward people has yet to be demonstrated in the Northern Hemisphere . . .

Maliciousness? Come again?

At the risk of appearing vain, I'll close with my own words from the introduction to the Birds of North America life history for the Monk Parakeet.

Early on, it was feared that this parakeet would thrive in its new home, ravaging crops as its range expanded. Over the years, this threat has not materialized and, in many areas, efforts to retrieve wild parakeets have been discontinued. It is worth noting that, in Argentina, agricultural losses attributed to the Monk Parakeet have never been accurately measured.