Union Terminal’s Winter Crow Roost
Posted On: 01/04/2017 - 2:28pm, Posted By: Emily Imhoff, Collections Manager - Zoology
Every winter, hundreds of American Crows (Corvus brachyrhynchos) gather each night in the Mill Creek valley in Cincinnati, usually in trees just north of Union Terminal, the historic home of Cincinnati Museum Center. They come to socialize and sleep together in a large group called a “roost.”
Trees located near Union Terminal where hundreds of American Crows sleep each night.
During the warmer months of breeding season, American Crows live in small family groups scattered over a large area. When cold weather arrives, dozens or even hundreds of families of these crows will flock from miles around to spend the nights together in a large communal roost. Scientists are not yet completely certain why they do this, but crows are known for their intelligence, so there are likely very good reasons for this behavior. Maybe it is simply the best possible location for sleeping, and they don’t mind sharing. Maybe they are gathering together to share information about food sources. Maybe they want to keep in touch with their neighbors and get to know all the new crows that hatched in this past spring. Maybe they are all gathering near a reliable food source. Maybe they gather because there is safety in numbers, and crow predators such as owls come out at night to hunt. Perhaps it is a combination of all these possible explanations!
American Crow mount from the Zoology Collection
Whatever the reason, they arrive by the hundreds each night, streaming in around dusk. They often settle on buildings and trees nearby before later moving to the roost trees where they will actually spend the night once darkness falls.
Click here to see footage of the crows flying along the Mill Creek valley towards Union Terminal.
When crows gather in a large group, they are very noisy. Every crow seems to have something to say! Luckily, most crows go to sleep before the local human population. However, in well-lit urban areas, crows sometimes stay up quite late, like kids at a slumber party that can’t quite settle down.
American Crows are not the only birds that you will see in large groups during winter: Blackbirds also form large winter roosts. The roosts can include multiple species, such as Brown-headed Cowbirds (Molothrus ater), Red-winged Blackbirds (Agelaius phoeniceus), Common Grackles (Quiscalus quiscula), and European Starlings (Sturnus vulgaris). You may see flocks of these birds foraging together during the day before they fly in groups during the evening to a massive communal roost site, which can include millions of birds.
You can learn more about American Crows online. There is also a growing number of popular science books about crows and other corvids (members of the crow family, including ravens and jays). Try checking one of these out from your local library!
“Gifts of the Crow: How Perception, Emotion, and Thought Allow Smart Birds to Behave Like Humans” by John Marzluff and Tony Angell
“Bird Brains: The Intelligence of Crows, Ravens, Magpies, and Jays” by Candance Savage
“The American Crow & Common Raven” by Lawrence Kilham
“In the Company of Crows and Ravens” by John M. Marzluff and Tony Angell
“Mind of the Raven: Investigations and Adventures with Wolf-Birds” by Bernd Heinrich “Bird Brain: An Exploration of Avian Intelligence” by Nathan Emery