BIRD MIGEATION. - 15 



winter's sojourn in Central or South America elect a short cut across 

 the Gulf of Mexico in preference to a longer land journey by way of 

 Florida or Texas. In fact, milhons of birds cross the GuK at its 

 widest part, which necessitates a single flight of 500 to 700 miles. 

 It might seem more natural for the birds to make a leisurely trip 

 along the Florida coast, take a short flight to Cuba, and thence a 

 still shorter one of less than 100 miles to Yucatan — a route only a 

 httle longer and involving much less exposure. Indeed, the earher 

 naturahsts, findmg the same species both in Florida and in Yucatan, 

 took this probable route for granted, and for years it has been noted 

 in ornithological literature as one of the principal migration highways 

 of North American birds. As a fact, it is almost deserted except 

 for a few swallows, some shorebirds, and an occasional land bird 

 storm driven from its accustomed course, while over the Gulf route 

 night after night for nearly eight months in the year myriads of 

 hardy migrants wing their way through the darkness toward an 

 unseen destination. 



To the westward a short route (see fig. 2, route 4) stretches a few 

 hundred miles from the coast of Texas to northern Vgi^a Cruz. It is 

 adopted by some warblers, as the Kentucky, the worm-eating, and the 

 golden-wmged, and a few other species, which seek in this way to 

 avoid a region scantily supplied with moist woodlands. 



OTHER ROUTES. 



Still farther west are two routes (see fig. 2, routes 6 and 7) which rep- 

 resent the land journeys of those birds from western United States that 

 winter in Mexico and Central America. Their trips are compara- 

 tively short; most of the birds are content to stop when they reach 

 the middle districts of Mexico and only a few pass east of the southern 

 part of that country. 



The routes as outlined on the map must not be considered as repre- 

 senting distinctly segregated pathways with clearly defined borders. 

 On the contrar}% they are merely convenient subdivisions of the one 

 great flightway which extends from North to South America*. There 

 is j)robably no single mile in the whole east and west line from north- 

 ern Mexico to the Lesser Antilles which is not crossed each fall by 

 migrating birds. What is meant is that the great buhv of both 

 species and individuals cross the GuK to eastern Mexico, while to the 

 eastward tlieir numbers steadily diminish. 



The map of the migration routes (fig. 2) shows route No. 1 that has 

 not y(!t ])('A',n diiscribed. It extends in an approximately north and 

 soutli line from Nova Scotia to the Lesser AntiUc^s and tlie northern 

 coast of Soutli America. Though more than a thousand miles 

 shorter than tin; niuin niigralion route, it is not (iniployed l)y any 



