47 



est comer or shadow before squatting, while the skimmer 

 crouches instantly, and with two or three instinctive flicks 

 of feet and legs, almost buries himself. 



5. — The sight of small but entire fish excites a newly- 

 hatched skimmer much more than does macerated fish. 

 Terns af first readily eat macerated fish and are not excited 

 b}^ the sight of entire fish until after the first week. These 

 facts would seem to indicate that young terns are fed, for a 

 few days at least, upon regurgitated fish; but the sharp 

 mandibles of a young skimmer merely cut macerated fish in 

 two, so skimmers are doubtless fed from the first on entire 

 fish. 



6. — The act of peckmg is instinctive to a certam extent, 

 but is acquired very slowly in this way. By imitation it is 

 learned quickly, and is performed successfully within a few 

 minutes. 



7. — The art of flying is wholly instinctive, the terns learn- 

 ing the use of their wings as soon as the primaries are large 

 enough to support them. 



