DISTANCES TRAVELLED BY BIRDS 69 



reached the north coast of South America. The 

 New Brunswick birds cannot be ready to leave before 

 the middle of July, and Mr Cooke allows them fifty 

 days for the trip, bringing them to the Gulf States 

 in September ;' he argues that this is proof that the 

 earlier migrants must have been birds from the 

 southern part of the range. Black- throated blue 

 warblers, Dendroica coerulescens , reach Cuba at about 

 the time that others of the same species are arriving 

 in North Carolina ; the first, he concludes, are birds 

 from the southern Alleghanies and the others from 

 northern New England or beyond (20). Other 

 species illustrate the same order which he calls 

 " normal/' but show that it is not an invariable 

 rule. 



Southern-bred Maryland yellow-throats, Geothlypis 

 trichas, reside throughout the year in Florida ; those 

 in the middle districts of the range migrate for a 

 short distance only, whilst the Newfoundland birds 

 pass over the winter home of their southern relatives 

 to the West Indies. The palm- warblers of the in- 

 terior of Canada travel 3000 miles to Cuba, passing 

 through the Gulf States early in October ; those 

 from north-eastern Canada travel later and slowly 

 and settle in the Gulf States, after a journey 

 of only half the distance. He sums up wisely 

 " No invariable rule, law, or custom exists in re- 

 gard to the direction or distance of migration. . . . 



