How Fast Can A Falcon Dive?: Fascinating Answers to Questions about Birds of Prey

Three. Raptor Behavior

THREE Raptor Behavior Question 1: How intelligent are birds of prey? Answer: An animal can have good vision and a good memory and not be particularly intelligent. We know that raptors generally have good memories, as is apparent when trained birds recognize former owners after a long absence. Raptors have relatively large eyes in proportion to their body, and their vision is superior to that of most other birds and mammals. Large eye size means the eye can admit more light, and the retina will be larger with room for more rods and cones to provide greater visual power. A correspondingly larger area of the brain is dedicated to efficiently process the flood of visual information. We know that the relative size of an organ has some relationship to its functional significance, and a larger brain is associated with increased cognitive skills and behavioral flexibility. Lazlo Garamszegi of the Université Pierre et Marie Curie in France, along with colleagues Anders Pape MØller and Johannes Erritzoe, examined the relationship between eye size and brain size in birds, and the correlation of eye and brain size with the demanding visual tasks of capturing actively moving prey and nocturnal activity. They conducted postmortem examinations of 2,716 birds and analyzed their measurements in conjunction with data obtained from handbooks and field guides on how they capture prey. Their results statistically demonstrated a positive relationship between eye size and brain size, and a positive RAPTOR BEHAVIOR 47 relationship between eye size and complexity of prey-capture technique. The Harris’s Hawk Parabuteo unicinctus, a North American raptor, uses a coordinated and cooperative hunting strategy when going after prey such as fast-moving small birds and large jackrabbits. This is probably the most advanced form of cooperative hunting known among birds, and it improves their capture rate and allows them to dispatch prey larger than themselves. Groups of from two to seven individuals, usually a pair and their offspring, use several different methods to hunt. They generally are found in desert and savannah habitats with dispersed cacti or small trees on which they can perch to spot prey. In one technique , several hawks pounce on a prey item in an open area. Another method is for one hawk to flush prey from cover while other hawks make the capture. Hawks take turns in the lead during extended chases after prey, so that if one hawk misses or tires, another can take its place and the chase will not flag. Alternatively, a second hawk will come from the opposite direction to intercept the prey. These hawks have become popular for falconry because of their cooperative nature and the ease with which they bond with a trainer and work in tandem with dogs and other trained Harris’s Hawks. Question 2: How fast can a raptor fly? Answer: Raptors are famous for their powers of flight, and most raptors are strong fliers, although there are some exceptions like the Secretary Bird Sagittarius serpentarius, which hunts while walking. Speed is essential to surprise and overcome prey that is fleeing at top speed. Red-tailed Hawks Buteo jamaicensis usually soar in lazy, slow circles while searching for prey, but they can drop quickly from 1,000 feet (over 300 meters) to snatch a rodent or rabbit. The small Sharp-shinned Hawk Accipiter striatus and European Sparrowhawk A. nisus zip through dense forest cover at speeds of 40 miles per hour (64 kilometers per hour) or faster in pursuit of prey. The large Golden Eagle Bird Strikes “It was the worst sickening, pit-of-your-stomach, fallingthrough -the-floor feeling I’ve ever felt in my life,” said the Airbus 320 pilot shortly after it crash-landed. “I knew immediately it was very bad.” In January 2009, he had just taken off from New York’s La Guardia Airport when he noticed a line of birds on the right side of the aircraft. An instant later the windscreen was filled with birds, and his first instinct was to duck. Then there was a thud and both engines stopped, and he smelled burning birds. He landed the commercial jetliner smoothly in the Hudson River adjacent to midtown Manhattan , and all 155 people on board were rescued in short order, thanks to the boats and helicopters that converged on the plane from both nearby shores. A bird strike was confirmed as the cause of the engine failure , and feathers...