Birds of Britain 



now drawing close together in a compact mass, or spreading 

 out in wedge-shaped formation, rising and falling as though 

 imhued with one mind. These flocks are to a large extent 

 migratory, and in the evening will often collect to roost on 

 reed-beds, which are laid flat with their weight. To enter 

 such a spot quietly just after dusk and then make a noise, 

 will afford one a sensation never to be forgotten, as they 

 rise with a sound like rolling thunder, caused by the clatter- 

 ing of thousands of wings against the reeds, while others 

 farther off, disturbed in turn, will also rise, until the whole 

 flock is on the wing, circling round our head with a subdued 

 roar which increases and diminishes as they approach or 

 retreat. In a few minutes, however, if we remain quiet, 

 they will soon begin to return, making no sound except the 

 rattling together of the reeds as they settle, and in a few 

 minutes all is quiet once more. At daybreak the flock 

 divides into smaller parties which set out to forage in the 

 neighbouring country. In the afternoon, as their hunger is 

 appeased, the scattered flocks begin to collect again, and it is 

 then that we may observe the evolutions referred to above, 

 till finally at dusk they are all roosting once more in the 

 reed-bed. After staying in the locality for some time, their 

 numbers being increased by fresh arrivals daily, they will 

 one night fail to return to their accustomed quarters, but 

 will instead start on a long journey on which we are unable 

 to follow them. Apart, however, from these large flocks, 

 smaller bodies will be found throughout the winter, wander- 

 ing over the country and even penetrating the parks and 

 gardens of our large cities. In March and April a migration 

 of small flocks returning to their accustomed breeding 



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