Sept., 1904 I 
THE CONDOR 
121 
and by the first week in June they reappear at their breeding grounds in the 
frozen North. What a journey ! Eight thousand miles of latitude separates the 
extremes of their elliptical course, and 3,000 miles of longitude constitutes the 
shorter diameter, and all for the sake of spending ten weeks on an Arctic coast! 
ARE BIRDS EXHAUSTED BY A LONG FLIGHT? 
During the spring migration of 1903 two skilled ornithologists spent the entire 
season near the coast of northwestern Florida, visiting every sort of bird haunt. They 
were eminently successful in the long list of species identified, but their enumera- 
tion is still more remarkable for what it does not contain. About twenty-five 
species of the smaller land birds of the eastern part of the United States, including 
a dozen common species, were not seen. Among these were the chat, the red- 
start, and the indigo bunting, three species that are abundant throughout the 
whole region to the northward. The explanation of this seems to be that these 
birds, on crossing the Gulf of Mexico, flew far inland before alighting, and thus 
passed over the observers. It would thus seem that the popular idea that birds 
find the ocean flight excessively wearisome, and that after laboring with tired 
pinions across the seemingly endless wastes they sink exhausted on reaching terra 
firma, is not in accordance with the facts. The truth seems to lie in almost the opposite 
direction. Endowed by nature with wonderful powers of aerial locomotion, under 
normal conditions many birds not only cross the Gulf of Mexico at its widest point, 
but may even pass without pause over the low, swampy coastal plain to the high- 
er territory beyond. So little averse are birds to an ocean voyage that many fly 
from eastern Texas to the coast of southern Mexico, though this 400 miles of water 
journey hardly shortens the distance of travel by an hour’s flight. Thus, the 
birds avoid the hot, treeless plains and scant provender of southern Texas by a 
direct flight from the moist, insect-teeming forests of northern Texas to similar 
country in southern Mexico. Under favorable conditions, birds can fly practically 
where, when, and how they please; consequently their choice of route and the dis- 
tance covered at a single flight are principally governed by the food supply. 
RELATIVE POSITION DURING MIGRATION. 
The relative position of the northern and southern groups of individuals as a 
species during the two yearly migrations is one of the doubtful points that late in- 
vestigations help to elucidate. The supposition is that in the case of species 
which adopt what might be called normal fall migration, birds which nest farthest 
south migrate first and proceed to the southern end of the winter range; those that 
breed in the middle districts migrate next and occupy the middle of the winter 
range; and finally, those of the northern part of the breeding range migrate last, 
and remain the farthest north for the winter. In other words, the migration is a 
synchronous southw'ard movement of the whole species, the different groups of in- 
dividuals or colonies retaining in general their relative positions. This has been 
generally believed, but only of late has it been clearly proved as to any 
particular species. 
An example or two will make this clear. The black and white creeper breeds 
from South Carolina to New Brunswick. In the southern part of its range it nests 
in April. New Brunswick, however, is scarcely reached by the earliest birds be- 
fore the middle of May, as the species occupies about fifty days in crossing the 
breeding range. If sixty days are considered the shortest possible time in which 
such a bird can build a nest, rear the young, molt, and be ready for the return 
journey, then no New Brunswick black and white creeper is ready to start south 
