i6 MIGRATION OF WARBLERS 



the Redstart, Oven-bird and both the Water-Thrashes. Nearly all 

 the Warblers of the western United States spend the winter in Mexico 

 and the contiguous portions of Central America. 



Knowing that so many Warblers from the eastern United States 

 spend the cold season in South America, and seeing the chain of 

 islands in the West Indies stretching from Florida to Venezuela, one 

 would suppose these islands to be the principal route of migration 

 between the two countries. As a fact no Warbler takes the shortest 

 course between New England and South America, by a direct flight 

 across the ocean, as is done by many of the water birds, and few 

 Warblers reach South America by way of the West Indies. The 

 Blackpoll and the Connecticut Warbler are probably the only ones 

 that use this route regularly and commonly, while the rest of the 

 Warblers of the eastern United States, follow along the coast to 

 Florida, then make a long flight across the Gulf of Mexico and thus, 

 by a roundabout course through Central America, reach their winter 

 home in South America. In the case of the Yellow Warbler, the 

 route actually followed is about two thousand miles longer than a 

 straight course across the Atlantic Ocean, The reasons for taking the 

 longer journey seem to be the impossibility of making so long a single 

 flight (2,500 miles) as would be required by the direct course from 

 New England to Venezuela and the scarcity of food in the West 

 Indies due to the small size of the eastern islands. 



The Warblers are night migrants ; the hundred-mile trip between 

 Florida and Cuba is apparently always made at night and at such 

 a speed that, in spring migration, many birds leaving Cuba after sun- 

 set, arrive on the Florida coast before midnight. The longer flight, 

 five to seven hundred miles, across the Gulf of Mexico is also evidently 

 made in a single night without stop or rest. How long a journey 

 is made each night when the bird is flying over land is as yet unknown. 

 But either the flight is short or else, after a single night's journey, 

 the bird stops for several days to feed, for the general advance of a 

 species in its northward migration is only a few miles per day. The 

 Black-and-White Warbler, an early migrant, averages only thirteen 

 miles per day and occupies a whole month in the journey from North 

 Carolina to Massachusetts. The late migrants move faster and the 

 Canadian Warbler, one of the latest, averages thirty miles per day 

 and in a month crosses the whole width of the United States from 

 the Gulf of Mexico to Canada. 



Warblers also perform long migration journeys by day. May- 

 nard (Birds E. N. A., Rev. ed., 1896, 585) describes a flight of 



