MOVEMENT IN BIRDS. 



The swifts, swallows, and nightjars bear down 

 upon the fl3^ng insect, taking it up in their wide 

 bills, without checking their course — the swift 

 especially will arrest the mayfly hundreds of feet 

 below without deviating by ahair's-breadth, from 

 the line of its exquisite curve. The fly-catchers 

 made sudden sallies from a vantage point of 

 branch or railing, bringing back their prey to the 

 perch, there to devour it. It would appear that 

 the fly-catching habit is in a state of evolution. 

 Many birds now, including the robin, chaffinch 

 and sparrow, take up their stations on the sides 

 of a stream when the mayfly is up, and work 

 precisely on the lines which, we believe, were 

 once peculiar to the fly-catcher. Yet they still 

 lack the art of the true fly -catcher : they fre- 

 quently miss their aim, and flutter awkwardly to 

 correct their course. 



It is certain that the starling has adopted new 

 methods within recent times. It may now be 

 seen on a still, sunny day, hawking for flies in 

 mid-air exactly as the swallow does, although 

 of course its aerial movements are wanting in the 

 ease and grace of the true masters of the craft that 

 have a racial experience of hundreds of centuries 

 behind them. 



Birds as Anglers. 



The movements of aquatic birds when seeking 

 food differ in accordance with their conformation 

 and habits. 



Some ducks dive : others feed only on the 

 surface. Around the Bass Rock the calm sea 

 may be seen thrashed into foam by the thou- 

 sands of gannets dropping as though turned into 

 marble, to the deeps below. These become 

 submerged and remain for an appreciable time 

 under water. 



55 



