Gulls Turn Cannibal on Sundays


Wikimedia Commons

Ah, Sunday. The day of rest. A day for sleeping in, having a big brunch and watching bad action movies on basic cable. A day for murdering your own children and consuming their bodies.

Wait. What?!

On the Dutch island of Texel, humans’ seven-day week has impacted some of the local wildlife in a pretty macabre way. The island sits in a rich fishing region, and its waters are crisscrossed by trawlers and shrimp boats through most of the week. Mondays through Thursdays, the boats are a boon for the local European Herring Gulls and Lesser Black-backed gulls, which follow them and feast on scraps and by-catch that get thrown overboard. On Friday, though, the buffet starts to get a little smaller, as many boats are homeward bound for the weekend. On Saturday and Sunday, the waters are nearly empty and the gulls start to get hungry without the surplus of human-supplied food. 

By Sunday, the lack of food can drive the birds to cannibalism, says CJ Camphuysen, a marine ornithologist who studied the gulls extensively for his PhD thesis. The gulls sometimes eat their own chicks or their own eggs, or they’ll snatch the unattended chicks of other birds and bring them to their nest for a family meal. 

According to Camphuysen, the area’s fishing fleet is projected to shrink in the coming years, but even before then, new policies about tossing by-catch overboard will rob the birds of some of the food they’ve come to rely on. Cannibalism won’t be a sustainable alternative for every day of the week, so he expects that many birds will move inland in search of alternate food sources. Young gulls will grow up without ocean views, but at least they’ll live through the weekend.