BRITISH BIRDS OF FASTEST FLIGHT 51 
and spine-tailed swifts {Chaetura), and it has been 
a great disappointment to me that I have never 
been able to get a satisfactory estimate of their 
rate of flight, as they never continue on a level 
course. On a small island on the coast of Crete 
I was recently given a good exhibition of what an 
Alpine swift can do. I was watching some of 
these birds feeding round cliffs in which several 
pairs of Eleonora's falcons were about to breed. 
Now, this delightful falcon is no mean flier, and 
as these swifts passed their clifl*, the falcons 
would come out against them like rockets. The 
swifts would accelerate and would seem to be out 
of sight before the falcons were well on their way. 
So confident were the swifts in their superior 
speed, that every time they circled round the 
island they never failed to ' draw ' the falcons, 
and seemed to be playing with them. I may add 
that these same falcons have little difficulty in 
overhauling and striking a rock -pigeon — itself 
no mean performer. I have also seen on record 
the case of falcons and swifts somewhere in India, 
where the former failed time after time to come 
up with his quarry. I, unfortunately, cannot 
trace the reference. 
**I hesitate even to guess at the speed to which a 
