BRITISH BIRDS OF FASTEST FLIGHT 43 
hunting together. If the swift had, say, ten 
seconds' warning, ^ I do not believe any falcon 
could touch it. As regards endurance, those 
birds with the greatest endurance are the swifts, 
swallows, petrels, and gulls. Swifts are probably 
endowed with the greatest powers, being denied 
by nature the advantages of perching, alighting 
on water, or resting on the ground. I have 
recently been studying the power of flight of 
various groups of birds, and find that the wings 
of the swift and petrel groups have wing outlines 
best suited for both endurance and speed. The 
falcon has a wing intended for short rapid flights 
and not for endurance. 
•' You have doubtless seen falcons huntingf. 
When they set out on a regular hunt they are not 
usually much faster than their quarry, unless it is 
some unfortunate non-game bird, and they only 
gradually overtake it. But I think a falcon usually 
makes full use of surprise and force of gravity. 
If these fail, he often abandons the chase, recog- 
nising that wearing a bird like a golden plover or 
teal dow^n by sheer endurance and honest straight- 
forward flying is a troublesome and not always 
successful task." 
^ This is a very considerable warning. — H. F. 
