is a feeling of increased security which conies from numbers. Certainly no enemy 

 can approach one of these bird assemblages without being spied by at least one 

 pair of vigilant eyes, when the lUjck is immediately notified by a few sharp 

 chirps — warning for every individual to seek safety in flight or to scurry to cover. 



WHAT MYSTERIOUS SENSE GUIDES TIIFCM IN TIIKIR LONG JOURNEYS? 



In what manner warblers migrate — that is, how they are guided on their long 

 journeys — is a moot question. Little mystery attaches to their ability to find 

 their way north or south in daylight, since the recognizable landmarks are 

 many and prominent. As most birds, especially the warblers, choose starlight and 

 moonlii^'ht nights for their trips, perhaps they arc similarly guided by night, and 

 natural landmarks, as mountains, ri\crs, and the coastline may point out much, if 

 not all, of their way. 



However plausible this explanation may sound in the case of birds migrating 

 over land, it utterly fails when applied to migrants whose journeys north and 

 south necessitate flight over long stretches of ocean, in some instances at least 

 2.000 miles, quite out of sight of land and all landmarks. 



In seeking an explanation of the mystery of birds* ability to find their way 

 under such circumstances, many arc inclined to reject the one-time sufificient 

 answer, "instinct," in favor of the more recent theory, the possession by birds of 

 another faculty, the so-called "sense of direction." This added sense enables 

 birds to return to a known locality with no other aid than an ever-present knowl- 

 edge of the right direction. 



But in the case of our wood warblers, there is little need of appealing to 

 another sense to guide them in migration, or, indeed, to anything out of the 

 ordinary save excellent memory and good eyesight. The five-hundred-mile flight 

 toward the tropics across the Gulf of Mexico is made by preference, and how- 

 ever it originated as a fly line, had it proved to be extra hazardous, it might have 

 been abandoned at any time in favor of the apparently safer West Indian route. 



But, after all, the Gulf trip involves few hazards, other than those connected 

 with storms, since the flight across the water, even at a slow rate, would necessi- 

 tate a journey of less than 24 hours, and this, no doubt, is quite within the 

 capacity of even the smallest and weakest of the famliy. Moreover, the South 

 -American Continent is too big a mark to be easily missed, and an error of a few 

 hundred miles north or south would make little dift'erence in the safety of the 

 birds. 



WHY WARBLERS MIGRATE 



It may be set down as an axiom that all birds which travel south in fall do so 

 because they must migrate or freeze or starve. Why some of them leave early 

 when food in their summer home is seemingly so abundant, is indeed a puzzle. 

 Once the nestlings arc on the wing and ready for the journey, off they go, old 

 and young. 



Nevertheless, by an apparently premature start they anticipate by a few 

 weeks the time of scarcity when they must go, and perhaps the lesson of bitter 



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