Monk Parakeet Overview, All About Birds, Cornell Lab of Ornithology

It may come as a surprise to see noisy, green-and-gray parrots racing through cities in the U.S. But Monk Parakeets, native to South America but long popular in the pet trade, established wild populations here in the 1960s. They are the only parakeets to nest communally; dozens live together year-round in large, multifamily stick nests built in trees and on power poles. These large group nests may be one aid to surviving the cold winters in adopted cities as far north as Chicago and New York.