The Mystery of Migration 



of observers whose writings are extant, Aristotle, naturalist and 

 philosopher of ancient Greece, was one of the first to discuss the 

 subject of bird migration. He noted that cranes traveled from the 

 steppes of Scythia to the marshes at the headwaters of the Nile, and 

 that pelicans, geese, swans, rails, doves, and many other birds likewise 

 passed to warmer regions to spend the winter. In the earliest years of 

 the Christian era, the elder Pliny, Roman naturalist, in his Historia 

 Naturalis, repeated much of what Aristotle had said on migration and 

 added comments of his own concerning the movements of the Euro- 

 pean blackbird, the starling, and the thrushes. 



In spite of the keen perception shown in some of his statements 

 Aristotle also must be credited with the origin of some superstitious 

 beliefs that persisted for several centuries. One of these, that of 

 hibernation, became so firmly rooted that Dr. Elliott Coues (1878),^ 

 one of America's greatest ornithologists, listed the titles of no less than 

 182 papers dealing with the hibernation of swallows. The hibernation 

 theory accounted for the autumnal disappearance of certain species 

 of birds by having them pass into a torpid state and so remain during 

 the cold season, hidden in hollow trees, caves, or in the mud of marshes. 

 Aristotle ascribed hibernation not only to swallows, but also to storks, 

 kites, doves, and others. Some early naturalists wrote fantastic ac- 

 counts of the flocks of swallows that allegedly were seen congregating 

 in the marshes until their accumulated weight bent into the water the 

 reeds on which they clung and thus submerged the birds. It was even 

 recorded that when fishermen in northern waters drew up their nets 

 they sometimes had a mixed "catch" of fish and hibernating swallows. 

 Clarke (1912) quotes Olaus Magnus, Archbishop of Upsala, who in 

 1555 published a work entitled "Historia de Gentibus Septentrionalis 

 et Natura," wherein he observed that if swallows so caught were taken 

 into a warm room they would soon begin to fly about but would live 

 only a short time. 



The hibernation theory survived for more than 2,000 years and, until 

 the winter home of the chimney swift was discovered in 1944 through 

 the recovery of banded individuals, it was occasionally repeated by 

 credulous persons to account for the sudden disappearance of the im- 

 mense flocks that each autumn gather in southern Georgia and north- 



^ Publications referred to parenthetically by date are listed in the Bibliography, p. 94. 



