If you’re a hawk trying to get dinner in mid-air by grabbing one juicy bat out of a huge swarm of bats, how should you proceed? A new paper in Nature partly written by three UNH professors at the Center for Acoustics Research and Education in Durham says they just charge in, willy-nilly, and hope for the best.
Here we show that Swainson’s Hawks Buteo swainsoni and other raptors attacking swarming Mexican Free-tailed Bats Tadarida brasiliensis steer by turning towards a fixed point in space within the swarm, rather than by using closed-loop pursuit of any one individual. Any prey with which the predator is on a collision course will appear to remain on a constant bearing, so target selection emerges naturally from the geometry of a collision.
Not very sophisticated but presumably it works. The paper is here.