THE nOTEBLNG OF THE KESTREL 209 



requires so much strength of wing or such an exer- 

 cise of force as when birds rise almost straight up. 

 Snipes do it, and woodcocks ; so also pheasants, rocket- 

 ing with tremendous effort; so also a sparrow in a 

 confined court, rising almost straight to the slates. 

 Evidently this needs great power. Hovering is very 

 interesting ; but not nearly so mysterious as at least 

 one other power possessed by birds* 



