Like some kinder, gentler version of Alfred Hitchcock’s The Birds, hundreds of robins have invaded our backyard. Fortunately, they’re not after me. They’re intent on the ripe red berries on a holly tree whose limbs overhang our yard.
Robins travel in large flocks this time of year here in the mid-Atlantic region. The ground has been frozen for weeks, so earthworms are off the menu. But the holly berries have just ripened, and they are among the few fruits on offer in winter. The robins arrive in hordes because this way they discourage competitors who don’t hang with such an imposing posse. But aren’t the berries poisonous? They were earlier in the season. But after a few rounds of freezing and thawing, the berries have become softer and less toxic.
If you’ve been invaded by robins, you’ll notice that they leave a terrible mess of dark purple or black gunk in their wake. It’s not bird poop. Robins have a long esophagus, so they can gobble and store a lot of berries quickly. (Another advantage they have over their avian competitors.) After some preliminary digestion, they regurgitate and spit out the seeds, making more room––fast––for more berries.