Jun 07 2013
Peregrines are famous for speed when diving on their avian prey. The dive was named a “stoop” because the word means “to bend the head or body downward and forward.”
The stoop is amazing in many ways:
- Peregrines dive at a 30 to 60 degree angle.
- They may start the stoop 5,000 feet away from the prey and drop 1,500 to 3,400 feet in altitude. These distances are exceeded when a falcon sky-dives with a falconer.
- Land-based speed calculations have clocked them at 100 to 273 miles per hour. Falconer Ken Franklin sky dives with his falcon at 242 mph.
- Peregrines can accelerate from 100 to 200 mph in eight seconds according to Ken Franklin.
- At 150 mph they tuck their wings tight and extend their shoulders, making their bodies into a diamond shape.
- At 200 mph peregrines pull in their shoulders and extend their heads to become extremely streamlined.
- Because their acute vision is at a 40 degree angle, they reduce drag and keep an eye on their prey by not diving straight at it. Instead they spiral downward keeping the prey to the side so they can see it. Their logarithmic spiral is rarely noticeable from the ground.
Here are three examples of diving peregrines, thanks to Chad+Chris Saladin.
Above, Mo is tucked into an arrow shape in Canton, Ohio.
Below, Rocky at Cuyahoga Valley National Park shows how peregrines hold their wings slightly open at the shoulder. If he was going faster his shape would be more angular.
And finally, Dorothy and E2’s son Henry shows off his flying prowess at Tower East in Shaker Heights, Ohio. His angle of attack is dramatic but he’s not traveling so fast that he has to tuck in his wings.
He stoops and conquers.
p.s. She Stoops To Conquer is a play by Oliver Goldsmith first performed in 1773.