The phrase “The First Robin of Spring” is misleading. We think it means that robins leave for the winter. Not so in Pittsburgh. We always have robins in December.
American robins (Turdus migratorius) are very versatile birds. They change their diet for the season, eating invertebrates in summer and fruit in winter. They take advantage of invasive species, especially earthworms and bush honeysuckle. They move quickly to places where we’ve changed the landscape, adopting our farms and suburbs. And they’re flexible on migration.
Studies have shown that American robins migrate an average of 300-750 miles but that average doesn’t tell the whole story. Some flocks head directly south, arriving in Florida by early December. Others take their time, pausing when they find abundant food along the way. Still others stay home or travel less than 60 miles from their breeding grounds especially in the last two decades as the climate warms.
Every December, huge flocks of robins feed and roost in Allegheny County. In 2008 Scott Kinsey discovered 100,000 of them roosting in Carnegie. The flocks stay through the month and are counted on the Christmas Bird Counts. Then, when the fruit is gone, the ground freezes, or there’s snow cover the robins move on.
In Pittsburgh they normally don’t leave until January.
(photo by Chuck Tague)