Hi Tweets,

Another thing I ran across in Leahy's book, The Birdwatcher's Companion that
got me thinking was the entry:

STOOP. ...It was once widely stated with authority that Peregrine Falcons
attained speeds of 180 m.p.h. (passing an airplane diving at 175 m.p.h.) and
even to 275 m.p.h. (Brown and Amadon, Eagles, Hawks, and Falcons of the
World, 1968). But recent attempts to confirm such velocities, using air
speedometers attached to stooping birds (how the heck do they attach them at
*those* speeds? '-) , have been unable to prove speeds in excess of 82 m.p.h.

Well, some say faster, some slower. I've seen nothing on a Peregrine's
terminal velocity for quite a while, but did come up with a maybe practical
seat-of-the-pants estimate of level flat-out flight.

A couple of weeks ago, the big juv female Peale's Peregrine came in over our
shoulders and--at a height of about five feet off the pond's surface--smoked
a straight-across transect of the SE pond at Iona Island in 2 seconds, give
or take a whisker (method: one mississippi, two mississippis--not exactly
quartz-atom-oscillation accuracy but ballpark, even if it may be closer to
third base than home-plate). Each pond is, conservatively, 100 meters
square. A two-second transect then required a velocity of 50 meters per
second, or 3,000 meters (dang near two miles) per minute, or 180,000 meters
per hour. At 1,000 meters to the kilometer, that's 180 km/hr, times 0.6 to
convert the velocity to m.p.h., equals 108 m.p.h.

That's level flight, likely with a fairly long slanting stoop behind us
begun well out over the Iona Causeway flats.

I was never much good at math, but that seems about right; the estimate
seems to tally with observation. Being an old dragstrip rat as a kid may
have helped put in an eye for speed, because ever since seeing my first
Peregrine ripping around, the claimed close-to-200-mph estimate has always
seemed quite on the high side to me. Quick as they were, they just never
seemed to go near as fast as those mid- to late 1960's Top Fuellers like Big
Daddy Garlits who *were* cranking out 180-200 mph (288-320 kph) runs in the
8-second range (thirty years later, I believe Top Fuel dragsters are
currently up to about 375 mph (600 kph) in the low 5's. Hooo.)

So does anyone know the latest in timed Peregrine stoops? Curious too about
Merlin, Prairie Falcon and Gyrfalcon top speeds, presumably in level flight.
Anybody ever timed these things through timing gates?

Michael Price The Sleep of Reason Gives Birth to Monsters
Vancouver BC Canada -Goya
mprice at mindlink.net