24 MICHIGAN BIRD LIFE. 
level, hence its resistance to the passage of a bird at that height would be 
lessened one-half. It does not follow, however, that therefore a bird at a 
height of three and one-half miles can fly at double its speed at the surface 
without increased effort. A moment’s thought will show how preposterous 
is such a claim. The very tenuity of the air, which lessens by one-half the 
resistance to the forward motion of the bird, must lessen in exactly the same 
proportion the supporting power of the air and its resistance to the wing- 
strokes, which alone give the bird headway. We may dismiss as absurd 
the claim that birds may double their speed by flying in rarified air. 
After careful search I have been unable to find a single instance in which 
the speed of any bird has been shown by actual measurement to reach over 
100 miles per hour. There are plenty of guesses, a few bold but unsupported 
assertions, and a number of more or less probable estimates. 
The figures furnished by pigeon fanciers give us some idea of the possi- 
bilities of the homing pigeon, so often miscalled the “carrier pigeon.” These 
records of course give only the average speeds, but these are certainly sug- 
gestive. The greatest velocity of which I find mention is eighty miles an 
hour, at which rate a homing pigeon ts said to have covered 114 miles in 
1892. Iam unable, however, to verify this statement. Another, and more 
likely record, is seventy-one miles an hour for a distance of eighty-two miles, 
while the average velocities of the winners in a large number of contests 
do not exceed forty miles an hour. In 1883 the best time made in eighteen 
races was 208 miles at the rate of fifty-five miles per hour. Over longer dis- 
tances the velocity is very much less, and in the longest flight of which I can 
find a record, that of a pigeon which flew from Pensacola, Florida, to Fall 
River, Mass., fifteen and one-half days were consumed in covering the 1,183 
miles, the average speed being seventy-six miles per day. 
In experiments tried with swallows in France it is claimed that one swallow 
flew 160 English miles in ninety minutes, giving a velocity of 107 miles an 
hour, but this record is open to serious question. 
Wild geese, and especially wild ducks, have been credited with a speed of 
nearly 100 miles an hour, yet in two cases where it was possible to measure 
the speed of flocks passing a given point, it was found that the geese flew at 
the rate of but 44.3 miles per hour, and the ducks at approximately forty- 
eight miles per hour, and in neither case did the height exceed 1,000 feet. 
These measurements were made at the Blue Hill Meteorological Observatory 
at Milton, Mass., by trained observers with the instruments used daily in 
determining the velocity of clouds.* In 1893 Dr. Hubert L. Clark noted 
two Buffle-head ducks flying along the Potomac River parallel with a train 
on which he was a passenger. The train was found to have a speed of about 
thirty-seven miles an hour, and the ducks were unable to keep up with it. 
Heinrich Gatke’s statement that the Golden Plover flies at the rate of over 
200 miles an hour is based on data which he misunderstood or misrepresented. 
He states positively that the Golden Plover migrates in autumn from Labrador 
to Brazil, over the Atlantic in one uninterrupted flight of 3,000 miles! He 
further assumes (without explanation) that fifteen hours is the longest time 
any bird could remain on the wing without food, and hence that the above 
flight of 3,000 miles is made in fifteen hours, at an average speed of “212 
geographical miles an hour.”t He does not explain exactly why this speed 
is 212 miles instead of precisely 200 miles per hour, as we should figure it, 
but we need not quibble about a paltry dozen miles in the case of birds moving 
*Science, New Series, V, pp. 26, 585-586. 
+ Heligoland as an Ornithological Observatory, Edinburgh, 1895. 
