Put A Camera On A Falcon’s Head, And You’ll See How They Are Such Accurate Killers
A BBC documentary inspired an animal researcher to mount minute cameras on birds of prey to understand their lethal hunting strategies. Using social networking media, Suzanne Amador Kane from Haverford College teamed up with falconers around the world to study their behavior. Their findings are published in an article in The Journal of Experimental Biology. The study claims that falcons target their prey by flying at an appropriate speed so that the target appears stationary in the falcon's visual field.
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Several falconers around the globe, at Amador Kane's request, conducted the experiment by attaching the miniaturized spy cameras to backpacks and tiny helmets worn by the falcons. The cameras filmed the predator-prey behavior. Then, Amador Kane and her undergraduate student Marjon Zamani looked the film frame by to study the falcons' pursuit of prey and attempted to either prove or disprove three possible hypothetical hunting strategies.
Very simple: the falcon flies directly at its prey. This strategy is pretty bad; it wastes the predator's time and energy while the prey can easily take evasive action. Under this approach, the prey would always be at the center of the frame in the movie.
The second hypothetical strategy was suggested a decade earlier by Vance Tucker. In this approach, the predator keeps its prey at a specialized visual range: an angle of 40 degrees off center. Falcons, according to Amador Kane have two regions of very sharp vision, one forward and the other 30 degrees to the side. Tucker's suggestion was rejected because Amador Kane and Zamani did not find this evidence in films. This strategy would compel the falcon to fly in a spiral path towards the prey. However, the duo found that the falcon rarely looked beyond 30 degrees.
The last proposed strategy is that the falcon, while fixing its prey in sight, maneuvers in a way that helps it keep the prey's image motionless against the background. This approach would help the falcon swoop directly on to the prey in the least possible time. This strategy, according to Amador Kane offers two advantages. The first advantage is that the prey stays in the central visual field of the predator, rather than off to one side, and the second advantage is that the victim cannot see the striking predator up until the time when it actually strikes.
This strategy appeared most logical and appealing to Amador Kane and Zamani. Other animals like bats, and even human follow the same strategy according to Amador. "Think about chasing a toddler around in the playground: they keep zigging and zagging away from you... so you just have to head them off," Amador Kane said.
Photo of falcon vis Shutterstock.
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