I34. Clark, Migrations of Shore Birds. [ a"? 



THE MIGRATIONS OF CERTAIN SHORE BIRDS. 



BY AUSTIN H. CLARK. 



The object of this paper is to explain, in as brief terms as 

 possible, what I consider is the main factor by which many of our 

 shore birds are guided in their migrations. I refer especially to 

 those species which pass southward over the western Atlantic, 

 from the eastern Canadian Provinces, past the Bermudas and the 

 easternmost of the West Indies to South America, as far south as 

 Patagonia, and return by way of Central America and the Miss- 

 issippi Valley. The bird which I have chosen as the best repre- 

 sentative of this class, and with which I shall mainly deal, is the 

 Golden Plover (Charadrius dominions), as it is large, well known, 

 easily identified (even when passing over at night), and does not 

 occur commonly, as do many other species (for instance the 

 Spotted Sandpiper, Actitis macularius, the Turnstone, Arenaria 

 interpres, and the Yellow-legs Totanus flavipes) , in the southern 

 part of its range at all seasons. 



Briefly summarized, the route taken by this plover in its migra- 

 tions {vide Cooke, Yearb. Dept. Agriculture, 1903, p. 371) is as 

 follows : — Starting from the breeding grounds in western Arctic 

 America, it goes to Labrador (arriving in August) where it fattens 

 on the ' curlew berries ' which are ripe at that time, and then 

 travels southward, leaving the continent at Nova Scotia, over the 

 sea past (sometimes four hundred miles or more east of) the Ber- 

 mudas, then just east of and over the Lesser Antilles, reaching 

 South America at the Guianas and the northernmost coast of 

 Brazil (about the first of September) . It soon disappears, but 

 reappears again on the prairies of Argentina, and goes as far 

 south as Patagonia, where it remains from September to March. 

 In March it appears in northwestern Colombia, Panama, and Cen- 

 tral America, passes up the Mississippi Valley, reaches the prairie 

 regions of the United States in April, crosses into Canada in May, 

 and is back on its breeding grounds in June. 



The question naturally arises, why do the birds come north by 

 a different route from that taken going south, and what guides 

 them in their long sea journey from eastern Canada over the 

 Atlantic to the Guianas ? 



