The United States was once home to two endemic parrots species: the Carolina parakeet, which was hunted to extinction, and the thick-billed parrot, a Mexican species that was driven out of its American range by a combination of shooting, logging and development. And yet, it is still possible to spot parrots in the wild in nearly all American states. As Ryan F. Mandelbaum reports for Gizmodo, a new study has found that 56 parrot species can be found across the country—the result of pet birds escaping or being released into the wild.
It is no secret that feral parrot populations exist in the U.S. Some groups, like the monk parrots of Chicago’s Hyde Park, are famous. But more work needs to be done to understand the biology of these parrots and their interactions with native bird species. A vital first step toward this goal is gaining a better understanding of the parrots’ distribution, a team of researchers writes in the Journal of Ornithology. So the scientists set out to track parrot populations across the country.
The team looked at citizen science records from 2002-2016, drawing on two databases that track bird sightings. The first is the Christmas Bird Count, an annual survey facilitated by the National Audubon Society that recruits birdwatchers to catalogue any birds they see and hear between December 14 and January 15. Audubon staff reviews the data before it is made public. The researchers also analyzed the eBird database run by the Cornell Lab of Ornithology, which allows birders to enter sightings from any trip. Experts flag atypical entries and consult with users to make sure that the sightings are accurate.
To determine whether a species was “established” in the U.S., the researchers looked for two criteria: signs of breeding and at least 25 sightings of the species during the period of study. Twenty-five, the researchers acknowledge in their report, is a “somewhat arbitrary” number, but it helped exclude rare species that made it to the wild but did not establish a self-sustaining breeding colony.
In total, the team counted sightings of 56 distinct parrot species in 43 different states. Twenty-five of these species showed signs of breeding in 23 different states. The most common species were monk parakeets, the red-crowned Amazon, and the nanday parakeet.
“Many of them were escaped pets, or their owners released them because they couldn't train them or they made too much noise—all the reasons people let pets go,” says Stephen Pruett-Jones, study co-author and an ecologist at the University of Chicago. “But many of these species are perfectly happy living here and they’ve established populations. Wild parrots are here to stay.”
Florida, California and Texas had the greatest number of introduced parrot species and supported populations of all 25 breeding species—perhaps unsurprisingly, given the states’ warm climate and the fact that most of the parrots have natural distributions in tropical regions. But there are large parrot populations concentrated in colder areas. Monk parakeets, for instance, have established colonies in at least 21 states, their success driven by several factors: they build their own nests, are able to nest on both natural and man-made structures and, during the winter months, adjust their diet to feed almost exclusively from backyard bird feeders.
The team’s report is based on observations from non-scientists, which “are certainly not perfect records of all non-native parrot species sighted in the USA,” the study authors note. Mistaken identifications are possible, and data from citizen scientists tend to be clustered in areas with more people, leading to uneven sampling. But since there are no standardized surveys of non-native parrots species in the country, “citizen science databases are a good starting point,” the researchers maintain.
As yet, there is no evidence that introduced parrots are detrimental to native bird species, though more research into this topic is needed. Monk parakeets have been known to be a nuisance to humans; they often nest on electrical transmission poles, telephone poles and electrical transformers, which can cause fires and power-outages. But people nevertheless seem to like having wild parrots around. Harold Washington, the first African American mayor of Chicago, once lived across from the Hyde Park monk parakeet colony, and affectionately came to view them as a “good luck talisman.” After Washington died in 1987, wildlife officials tried to remove the parrots, but the effort came to a halt when the public banded together and threatened a lawsuit.
Non-native parrots in the U.S. may also become important to the conservation of species that are endangered in their natural ranges. According to Pruett-Jones, there are already more red-crowned Amazons in California than there are in their native habitats in Mexico.
“Because of human activity transporting these birds for our own pleasure, we have inadvertently created populations elsewhere,” he says. “Now for some of these parrots, they may become critical to the survival of the species.”