For the Birds Radio Program: Seagulls
In Duluth, it’s a bit of a stretch to call our gulls “seagulls,” but it’s not so inappropriate on the actual sea. Laura was just on Long Island watching gulls dropping hard-shelled animals in hopes of breaking it to get to the food within.
Seagulls Last week I went out to Long Island with my sister-in-law to visit relatives, and spent a couple of mornings on a quiet little beach at Louse Point with my dog Photon. Photon’s gone swimming in Lake Superior and a lot of smaller lakes, but never has she stepped into salt water before. She seemed a bit surprised by the taste but absolutely loved the buoyancy—it was harder getting her to finally leave the water there than it’s ever been before.
As fun as it was watching her cavorting, my eyes kept being drawn to the gulls. I suppose I could legitimately call them seagulls, but with my birder brain, I can’t help but assign them their proper names—Ring-billed, Herring, and Great Black-backed Gulls. They’d glide through the air above the fairly deep water, drop down and grab a crab, conch shell, or other critter, fly to shore with it, gain altitude, and suddenly let it go, dropping it on a large rock or the road. If it broke apart, they’d fly down for a tasty meal. If it didn’t, they’d pick it up, fly up even higher, and drop it again. I watched one Herring Gull drop some sort of shelled creature repeatedly on the roof of a house, and wondered how often it did that, and how the people inside felt about it.
I’ve read a lot about gulls cracking shells, but haven’t seen it very much until this trip, so naturally I googled the behavior when I got home. And it was fun reading all the ways that various scientists over the years glossed over the concept that these gulls might have actually figured out that 1) there was food in these shells and 2) if they dropped the shells on something hard and the shells broke, they could get at that food. One study in 1930 concluded that the gulls didn’t drop the shells preferentially on hard surfaces, but studies from 1946, 1958, and 1978 showed pretty conclusively what my observations on Long Island suggested—that the gulls do in fact fly over hard surfaces to drop the shells. Young gulls have to work much harder than adults to get meals this way—sometimes they don’t pick shells with food inside, and they have more trouble gauging how high up they should drop them and over what surfaces. But it doesn’t take many months for them to get reasonably good at the process.
Although it’s obviously clever for gulls to drop hard shells on the hard ground to crack them open, sometimes they drop softer items that they could have easily penetrated with their beaks. Herring Gulls often drop starfishes, and one observer in 1947 reported a Great Black-backed Gull inexplicably but repeatedly dropping a dead rat from the air. That predated Julia Child’s TV show, so I’m not sure how the gull learned about tenderizing meat.
However and whyever they learn to do it, it was very impressive seeing how many broken shells were strewn about the road to Louse Point, and how easy it was to observe gulls carrying large items and dropping them. I took quite a few photos—I posted one on my twinbeaks blog, and when you click on it it’s easy to find others. Gulls are so common and ordinary that it’s sometimes hard to remember just how uncommonly extraordinary they really are.