SAND DUNES AND SALT MARSHES 



and entirely immerse his head, to emerge 

 without difficulty, carrying in his bill what 

 appeared to be a small silvery fish. I have 

 seen them, after sailing and hovering over the 

 water in a high wind with the spray dashing 

 about them, skilfully pick up food from the 

 tops of the waves. 



It is easy to picture an island community 

 of grackles becoming more and more addicted 

 to a maritime life, owing perhaps to the 

 shrinking of their terrestrial food supply 

 from change of climate or land subsidence. 

 Would not these habits become in time as 

 much inherited as are similar habits in the 

 gulls'? Or, to put the question in another way, 

 were not the inherited traits of the gulls orig- 

 inally acquired? 



The Ipswich sparrow is the only strictly 

 dune dweller among the birds. Its summer 

 home is on Sable Island, an island of sand 

 dunes off Nova Scotia, and it spends its win- 

 ters along the sandy portions of the Atlantic 

 coast. It is evidently a near relation of the 

 Savannah sparrow, who is somewhat smaller 

 and darker, and lives in marshes and open 

 fields from Labrador to New Jersey. As the 

 glaciers receded, we can picture the gradual 



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