DNA unlocks parakeet's hidden past
South American conures are closest relatives of North America's extinct parrot
Published: October 16, 2012
The Carolina Parakeet has been extinct since at least the 1920s, and the gaps in ornithologists' understanding of it are many. Now, thanks to a new DNA analysis of parakeet specimens, scientists have unraveled the bird's evolutionary history.
John James Audubon depicted seven Carolina Parakeets in this painting. The species went extinct about a century after the artist put down his brush.
The species was the only naturally occurring parrot in eastern North America, but its closest relatives were not found in nearby Mexico, Cuba, or the Caribbean. Rather, says Jeremy Kirchman of the New York State Museum and Erin Schirtzinger and Timothy Wright of New Mexico State University, the parakeet's kin are from South America.
The researchers found that its DNA is most similar to those of the Nanday, Sun, and Golden-naped Conures; a fourth species, Jandaya Conure, is thought to be another close relative, but its DNA was not part of the study. Like the parakeet, three of the four conures are known for bright yellow and orange plumage. The scientists suggest that "this striking coloration evolved in the shared ancestor" of the birds but was partially lost in the Nanday Conure, which lacks yellow feathers.
Writing in the April 2012 issue of The Auk, Kirchman and his colleagues also note that the DNA evidence confirms that the Carolina Parakeet is not related to a familiar species with which it shares fully feathered ceres -- Monk Parakeet, whose closest relative is the White-winged Parakeet.
The discovery of Carolina Parakeet's relationship with South American species, rather than parrots that were geographically closer to its range, suggests that the parrot family colonized North and Central America in more than one wave.
"If Neotropical parrots indeed had their original diversification in South America after colonization from Antarctica, as is generally agreed," the researchers write, "this result suggests that there have been several distinct colonizations of Central and North America by different lineages."
And now that scientists know for sure what Carolina Parakeet DNA looks like, they can use it as a barcode to test other potential remains of the species. Of particular interest are two sets of eggs that reside in the Florida Museum of Natural History. They were collected in April 1927. If confirmed to be parakeet eggs, they'd be the latest known specimens of the species.