SIDE LIGHTS ON BIRDS 



are propelled by the backward sweep of the webbed 

 feet alone. The storm petrel, the smallest of web- 

 footed birds, said to derive its name from the 

 Apostle Peter, runs up and down the billows of the 

 Atlantic as nimbly as the ringed dotterel trips over 

 its native sand-dunes. Most birds that seek their 

 living in water are web-footed, but sandpipers, 

 pheasants, and other non-web-footed birds swim 

 well on occasion. 



When one watches the infinite variety in the 

 movements of birds, and how readily their forms 

 respond to the eager impulses from within, it is not 

 difficult to see how, as circumstances and environ- 

 ment change through the ages, new impulses may 

 arise, and in turn create new movements. For 

 example, the dipper has long been regarded as 

 something of an anomaly in bird life. It would 

 appear that this member of the strictly terrestrial 

 thrush family took on a habit in the dim past 

 of searching for food on the margins and partly 

 submerged stones of rivers. Deeper and deeper 

 it thrust its head into the water seeking for 

 aquatic beetles, and other insects. At length it 

 came to disappear altogether, and became a diver. 

 Still it has not acquired even yet any of the char- 

 acteristics of the true diving birds. It is still a 

 thrush. " The acutest observer," — said Darwin, 

 ' ' by examining the dead body of a dipper would never 

 have suspected its sub-aquatic habits." Its feet 

 are unwebbed, without even the slight fringing 

 membrane of the grebes and coots. Its way of 

 going under water, too, resembles more nearly that 

 of a thrush taking a header than the manner of a 

 true diving fowl sliding into its native element." 



In many ways the evolution of movement may 

 be inferred by noting the manners of ceitain birds. 

 Any one who watches the turns and twists of a 



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