40 AMID THE HIGH HILLS 
" All the gyrfalcons are much faster on the 
wing than peregrines, and having trained and 
flown both species of these falcons for many years 
I have been enabled to prove this beyond doubt." 
The swift has still to be considered. There 
are three species of swifts which rank as British 
birds : the common swift (Cypselus apus), the 
Alpine swift {Cypselus melha), and the spine- 
tailed or needle- tailed swift {Acanthyllis caudacuta 
or Chaetura caudacuta caudacuta). The Alpine 
swift is a rare visitor here, only about thirty 
having been satisfactorily identified at different 
times from April to October in different parts 
of these islands, but chiefly in the southern part 
of England. It breeds in mountains throughout 
Central Europe, and eastwards to India. The spine- 
tailed swift is even a rarer visitor here, only two re- 
corded instances of specimens having been obtained 
— one in Essex in 1846 and one (said to have been 
in company with another) in Hampshire in 1879. 
It breeds in the mountains of North-eastern Asia, 
and in winter goes as far south as Australia. 
Swifts are perhaps the most powerfully winged, 
in proportion to their weight, of all British birds. 
Their form is that which has been found to 
make the fastest sailing vessel — fuU forwards and 
