LOVE AND COURTSHIP AMONG BIRDS. 265 



themselves, or strut before the females; others, again, by special 

 noises which they produce. 



While a few falcons, and all owls, express their desires chiefly, 

 if not exclusively, by means of loud cries, other birds of prey 

 indulge, either alone or in company with their mates, in a mag- 

 nificent play of wings, which is now a kind of round dance, and 

 anon becomes a perfect frenzy. Eagles, buzzards, peregrine falcons, 

 kestrels, and lesser kestrels circle round each other for hours at a 

 time, ascend spirally to giddy heights, exercise, obviously to their 

 mutual pleasure and satisfaction, all the arts of flight of which they 

 are capable, utter shrill cries from time to time, spread out their 

 plumage in the sunlight, and, finally, glide slowly down and assume 

 a dignified sitting posture, there to resume their caressings. Kites, 

 which behave in an essentially similar manner, let themselves sud- 

 denly down, with half -closed wings, from a very considerable height, 

 until they are just over the ground, or a sheet of water, then begin, 

 more quickly than usual, to describe a series of curves, remain 

 hovering for some time over a particular spot, or execute other 

 wonderful movements, then slowly soar again to their former height. 

 Harriers fly for some time with apparent indifference behind the 

 desired mate, then begin to circle round her, describe with her a 

 series of intersecting curves, and, suddenly leaving her, soar, with 

 head directed upwards, almost perpendicularly up to a considerable 

 height, increasing, at the same time, the speed of their ordinarily 

 leisurely flight to a surprising rapidity; then, tumbling precipitately 

 over, fall with almost closed wings to near the ground, circle there 

 once, twice, or oftener, ascend again and proceed as before, till at 

 last the female makes up her mind to follow their example. But 

 all these which we have mentioned are surpassed by the bateleur, 

 or mountebank, a harrier about the size of an eagle, living in the 

 interior of Africa, and one of the most remarkable of birds of prey in 

 form and behaviour (p. 188). Its marvellous flight is at all times 

 likely to attract the attention of observers, but during the pairing- 

 time this becomes an incomparable mountebank performance in the 

 air, a bewildering acrobatic display, which seems to unite in itself 

 all the arts of flight practised by the other birds of prey. 



