06/20/2026
South American parrots have been living wild in Chicago since the late 1960s. They survive winters that drop below zero by building communal stick nests the size of hay bales on power poles and tree branches, each nest containing up to twenty separate apartments with individual entrances, and by eating almost nothing but backyard bird feeder seed from December through February. They are bright green, loud, and visible from a block away. Most Chicagoans who live near them have no idea they are not supposed to be there.
The monk parakeet is native to the grasslands of Argentina. It is the only parrot species on earth that builds its own nest from sticks. Every other parrot nests in cavities, tree holes, cliff faces, or burrows. The monk parakeet weaves small twigs into a massive communal structure, adding chambers as the colony grows, until the nest resembles a rough ball of sticks three or four feet across hanging from a branch or bolted to the crossarm of a utility pole. Each chamber has its own entrance hole. Each pair raises its young in its own compartment. The structure is occupied year-round, not seasonally, and the thermal mass of dozens of birds roosting together inside a thick wall of interlocking twigs keeps the interior temperature survivable through nights that would kill any individual bird sleeping alone on a branch.
That nest architecture is the reason monk parakeets are the only wild parrot species in the United States breeding in cold climates. Twenty-five parrot species now breed wild in twenty-three states. Every other species is restricted to warm regions: Florida, Texas, Southern California, Hawaii. The monk parakeet breeds in Chicago, New York, Connecticut, and New Jersey. It does this because it carries its own insulation with it in the form of a communal apartment building made of sticks that no other parrot on earth knows how to build.
In the 1950s and 1960s, tens of thousands of monk parakeets were imported from South America into the American pet trade. Inevitably, birds escaped or were released by owners who underestimated how loud a parrot is at six in the morning. By 1968, wild colonies were breeding in at least ten states. In Chicago, the first documented wild nest appeared in 1973 in Hyde Park on the South Side, near the University of Chicago campus.
Stephen Pruett-Jones, an ecologist at the University of Chicago who usually studied wrens in Australia, noticed a group of monk parakeets on his daily commute in 1988 and realized nobody was researching them. He started sending students out to count and map the birds. Over the following decades, his lab documented nearly five hundred monk parakeet nests across the Chicago region, stretching from near Milwaukee in the north to Chesterton, Indiana in the south. He has never actually held a wild parrot in the United States, he said. But he became the spokesperson for parrot research because when he saw the monks in Chicago, he realized nobody else was working on them.
One of Pruett-Jones's students discovered the winter survival mechanism. From December through February, Chicago's monk parakeets switch almost exclusively to backyard bird feeders. They stop foraging in parks and open grass. They eat sunflower seed, millet, and whatever else homeowners put out for cardinals and sparrows. Without human-provided seed, the parakeets would almost certainly not survive the coldest months. In brutal cold snaps, some do not. Pruett-Jones has received reports of dead monk parakeets found on the ground after sustained sub-zero temperatures. The communal nest and the bird feeder together keep the colony alive. Remove either one and Chicago is too cold for a South American parrot.
Harold Washington, Chicago's first African American mayor, lived across the street from one of the city's best-known parakeet colonies in Hyde Park. He called them a good luck talisman. After Washington died in 1987, the USDA attempted to remove the Hyde Park birds as part of a broader effort to eradicate naturalized monk parakeets nationwide. The agency considered them a potential agricultural pest based on crop damage in Argentina. Hyde Park residents threatened a lawsuit. The USDA backed down. The parrots stayed.
The utility company has a different relationship with them. Monk parakeet nests built on power poles and transformer equipment can cause short circuits and outages. ComEd periodically tears nests down. The parakeets rebuild. The cycle has been repeating for forty years. A nest removed from a utility pole in March will be reconstructed on the same pole by May because the birds are not selecting random locations. They are selecting structures with the electrical warmth and elevation that their Argentine instincts interpret as ideal nesting sites.
Fifty-six parrot species have been spotted in the wild across forty-three states. Twenty-five of those species are now breeding. Most will never expand beyond the warm latitudes where they were released. The monk parakeet is the exception because it solved the cold problem twice: once through nest architecture that no other parrot possesses, and once through a dietary switch to human bird feeders that no biologist predicted. A South American grassland bird is raising chicks on Chicago power poles in January because it builds its own apartment building out of sticks and eats from the same feeder as the chickadee next door.
Source: University of Chicago / Cornell Lab of Ornithology / WBEZ Curious City / Block Club Chicago
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