146 OBSERVATIONS ON BIRDS. 



times clinging to the twigs with their bills and claws, 

 and pulling at them, at the same time flapping their 

 wings in order to support themselves. The nests 

 are lined with grass, and other vegetable matters of 

 that kind. One year we noticed a number of nests 

 having the leaves of pine-apples interwoven with the 

 sticks ; these had been obtained from a dung-hill in 

 the garden near a hot-house, out of which the dead 

 leaves of these plants had been ejected. 



In large rookeries, during the breeding-season, a 

 strong smell proceeds from these birds, very percepti- 

 ble to persons walking under the trees on which the 

 nests are built. This seems to arise partly from the 

 number of individuals collected together, and partly 

 from the quantity of dung dropped. Where this 

 dung falls, nettles vegetate very luxuriously. 



March 18th, 1843. The nests of the rooks appear 

 finished, yet few birds can be observed actually 

 sitting. They keep stationary on the trees, perched 

 in pairs on the very uppermost twigs, which bend 

 beneath their weight. They spend much of their 

 time in cawing, accompanied by a shaking of the 

 wings ; the hens receiving the attentions of the cock. 

 Every now and then I see them pulling at the blos- 

 soms of the elms, on which trees the nests are mostly 

 built. 



