160 NATURE'S STORY OF THE YEAR 



above the other, and swoops at her. She 

 descends, and, as the aggressor approaches, both 

 birds take a more vertical direction, with the result 

 that they swoop at a great pace, and their swish- 

 ing rush through the air can be heard at some 

 distance. The male seems never to actually strike 

 the female, but swings up from the attack, and 

 continues to mount till far aloft. The poor female 

 bird rushes along at a lower level, turning this 

 way and that to snatch her meal ; but the male is 

 following, and immediately renews the attack. 

 This habit of the birds may account for the worn 

 or bitten condition of the tips of the tails of swifts 

 which, on a few occasions, I lifted off the nest. 



On the particular evening in question, swifts 

 were chasing each other noisily, as is their wont ; 

 and I, tired and lazy, sat watching them. At the 

 first sign of dusk a great mob of them began to 

 ascend, and continued their gambols in mid-air. 

 But they gradually rose higher, until at last the 

 query arose in the mind : when would they come 

 down to their nests ? But the precious minutes 

 of daylight were rapidly drawing to a close ; and 

 yet the birds stayed up, and went higher. Then 



