experience in the history of the several species has taught them to go when all 

 the conditions are favorable. It is true that every winter a few birds, often a 

 few individuals of a given species, winter far north of the customary winter 

 home. Some of these are evidently stragglers or wanderers which, for some 

 unexplained reason, failed to accompany the rest of their kind on the southward 

 migration. They in no wise affect the general statement, being exceptional in 

 every way. 



A few of our warblers in Florida and on other parts of our southern coast 

 do not migrate ; but the almost universal rule in the family is to abandon the 

 summer home when the care of the young ceases and to go far southward ere 

 they stop for the winter. Indeed, the males of many species do not trouble 

 themselves much with the care of the nestlings, but prepare to migrate before the 

 young are well on the wing. 



A still more flagrant case is that of the hummingbirds. The male deserts the 

 female when she is still on her eggs, shifting the responsibility of caring for 

 the family entirely on her devoted head, while he disports himself among the 

 flowers, leaving for the south long before his exemplary mate and the young are 

 ready. 



Some of our species, however, while migrating southward, are satisfied to 

 remain all winter within our boundaries. Thus the pine and palm warblers winter 

 in the Gulf states, while a greater or less number of individuals, representing 

 several species, winter in southern Florida. The great majority, however, winter 

 south of the United States, in Central and South America. 



Thus Professor Cooke tells us : "The prairie, black-throated blue. Swain- 

 son's, Bachman's, Cape May, and Kirtland's warblers go only to the West Indies. 

 The worm-eating, myrtle, magnolia, chestnut-sided, black-throated green, hooded, 

 blue-winged, Nashville, orange-crowned, parula, palm, and Wilson's warblers, and 

 the chat, go no farther than Central America, while many species spend the 

 winter in South America, including some or all the individuals of the black and 

 white, phothonotary, golden-winged, Tennessee, yellow, cerulean, bay-breasted, 

 block-pol, Blackburnian, Kentucky, Connecticut, mourning, and Canada war- 

 blers, the redstart, oven-bird, and both the water-thrushes. Nearly all the warblers 

 of the western United States spend the winter in Mexico and the contiguous por- 

 tions of Central America." 



VAST NUMBERS SUCCUMB 



The northward journey in spring, away from the land of sunshine and plenty 

 to the land of uncertain spring weather, is another matter. Probably if all birds 

 that habitually abandon the north and winter in the south were to nest there, 

 their quota, added to the number resident in the tropics, would be too great for 

 the means of subsistence. 



Nevertheless, birds are not forced away from their winter quarters by in- 

 clement weather or impending famine, but by the subtle physiological change which 

 warns them of the approach of the mating season and fills them with new desires, 



830 



