This is Scientific American's 60 Second Science. I'm Lucy Wong.

You might expect to hear parrots like these in the wild of South America, but the birds are actually nesting in the middle of Chicago.

Despite being known as monk parakeets, the green and gray squackers are true parrots, and they've been living in the Windy City since the 1970s, but not just there.

There are monk parakeets in many, many states. They're breeding in around 21 states.

Jenny Euling, a PhD student now at Cornell, who was at the University of Chicago when she studied these birds.

Certain populations will pop up in certain states and then you know

disappear but they're by far the most widespread of any of the species.

Euling wanted to know how many non-native parrots were living in the US. To do this...

We used E-bird and Christmas Bird Count or CBC and we used these two databases because they

have the largest spatial distribution of data basically for the United States.

Euling and our team looked at data collected from 2002 to 2016

and deduced that there were 56 different species of Paris living free in 43 states. Of these species, 25 of them had

become naturalized, that is, able to successfully breed and maintain their own

population without the addition of additional

individuals from captivity. Most of these non-native parrots were either

released by owners or escaped from captivity. Some establish breeding populations and some of these new

populations are saving entire bird species. The Red Crown parrot is declining in its

native range but it's actually increasing in the U.S. and it's becoming pretty common.

And so I think that leads to a really interesting question of, you know, could we possibly use

these populations of non-native parrot species to understand the biology of a species

that's declining in its native range.

The study is in the Journal of Orthology.

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