European catfish typically trawl the bottom of freshwater lakes and rivers for food, opening their flat mouths to consume crustaceans, worms, small fish, and even the occasional frog. But along one stretch of island in the Southwestern region of France, the invasive species seems to have taught itself how to hunt unsuspecting pigeons. (Check out the video above.)

French biologists from the University of Toulouse wanted to observe this adaptation firsthand, and set up shop on a bridge overlooking the Tarn River, where the birds gather to bathe. They discovered that the catfish are squirming their way into shallow waters before lunging at birds, temporarily beaching themselves in the process — a hunting technique more associated with killer whales. If successful in chomping down on a pigeon, they violently drag the prey back into the water. The catfish's efforts succeeded 28 percent of the time.     

What makes these catfish such adept killers? Researchers noticed that the fish only attack pigeons that fidgeted in the water. Birds that remained still, even when partly submerged, largely went untouched. This led researchers to believe that the catfish sensed prey using the water's vibrations rather than their eyesight. 

The biologists aren't sure how this feeding habit started. Nonetheless, the European catfish now joins other species that have developed a taste for pigeon flesh. Like this turtle, for instance:

And this pelican: