In winter, flocks of American Robins spend the night together. Typically, a few dozen to a few hundred birds roost communally in trees or an old barn, or under a bridge. But larger robin roosts can number in the thousands, or even tens of thousands! In 2007, observers near St. Petersburg, Florida, estimated that 720,000 robins were roosting on an island of mangrove trees. If the average robin weighs 2.7 ounces, that was nearly 61 tons of robins!
