26 THE AUDUBON BULLETIN 



Illinois Birds As Travelers 



Under this title Prof. Frank Smith of the Department of Zoology of 

 the University of Illinois has contributed to the Illinois, 1921, Arbor and 

 Bird Days an article of unusual interest and value. The state Department 

 of Public Instruction is doing a fine service in sending such articles into 

 every school in the state. Permission has been secured to reproduce the 

 major portion of the article in this Bulletin. 



Professor Smith writes: "It is apparent that the birds of about seven- 

 eighths of our different species are travelers, making annual journeys back 

 and forth between their summer and winter homes. The regions occupied 

 as such homes are now known for very nearly all of the three hundred 

 and more different kinds of Illinois birds, and the principal facts are 

 published so that anyone can look them up. Furthermore, the general 

 routes followed by the birds in traveling back and forth between summer 

 and winter homes are also known for most of the species. An examination 

 of the published data shows that birds of nearly one-half (48%) of the 

 species regularly found in Illinois have their summer and winter homes 

 entirely separated, necessitating a migration of all of the individuals of 

 those species over the intervening territory, annually, in each direction. 

 For some species these may be journeys of but a few hundred miles, while 

 for others they are thousands of miles. Summer residents of Illinois that 

 winter in the states next south of us do fiot have far to travel, but birds 

 that nest in or near Alaska and the Arctic regions, and have their winter 

 home in the southern half of South America, make journeys of 8,000 or 

 9,000 miles twice each year. 



The birds of more than one-third (36%) of our Illinois species journey 

 beyond the boundaries of our country to reach their winter homes. A few 

 kinds winter in the West Indies, others in Mexico, a greater number in 

 Central America, and representatives of more than one-fifth (21%) of our 

 Illinois species push on into South America for their winter feeding 

 grounds. Among these are included many thrushes, warblers, swallows, 

 tanagers, flycatchers, cuckoos, snipe, and sandpipers. 



The accompanying map shows the migration routes followed 

 by most birds that leave the United States for the winter season. It is 

 similar to one in a bulletin of the United States Department of Agri- 

 culture (No. 185) on the subject of bird migration, prepared by W. W. 

 Cooke who, when living, was a leading authority and writer on that sub- 

 ject. 



Most Illinois birds which migrate beyond the boundaries of the United 

 States doubtless follow route 3, which involves a direct flight across the 

 Gulf of Mexico to the southeastern part of Mexico, and then travel over- 

 land into Central America, and many of them go still farther into South 

 America. A few, like the cliff swallow, fly around the gulf through Mex- 

 ico (route 4) ; and a few, like the bank swallows and bobolinks, follow 

 route 2 via Cuba and the Carribean Sea directly to South America. 



It soon becomes apparent to those who make an effort to keep ap- 

 proximately complete records of the birds found in their localities, that 



