Michigan Ornithological Club 19 



/ 



SUGGESTIONS FOR A METHOD OF STUDYING THE MIGRA- 

 TIONS OF BIRDS.* 



LEON J. COLE. 



Many theories have been advanced to account for the striking migrations 

 of birds ,and as has been shown by Wallace, 1 and in a somewhat modified 

 way by Brooks, 2 the law of natural selection is capable of accounting for 

 the origin of this habit, which has become so permanently fixed in 

 nearly all our birds. But there are many phenomena connected with 

 migration to account for which even satisfactory hypotheses are not as 

 yet forthcoming, chief among which may be cited the question of how 

 birds are able to find their way unerringly over hundreds, or even thou- 

 sands, of miles of land and water to a particular locality which they have 

 left the previous year. Before these questions can be answered a much 

 better knowledge of the facts is necessary. 



Various methods have been employed for obtaining data relative to 

 the migration of birds, and an immense amount is contained in miscellaneous 

 notes scattered throughout the ornithological literature. These notes embody 

 in large part the records of single observers on the flights of birds, theif 

 abundance at various times of year, and especially records of their first arrival 

 in the spring. The collection of this last mentioned data, together with 

 some further notes on the time the bird became common, whether it breeds 

 at the station of the observer, etc., has been carried on in an extensive and 

 systematic way in this country for many years by the United States Depart- 

 ment of Agriculture, under the able direction of Dr. C. Hart Merriam. 

 A very excellent report of some of the results of the first of this work in 

 the Mississippi Valley was prepared by Prof. W. W. Cooke, 3 but so far as I 

 know nothing of the kind has been attempted with the mass of data which 

 must have accumulated since that time. During the period of its activity the 

 Michigan Ornithological Club appointed a committee to collect similar data 

 in the Great Lake region, blanks being used almost identical with those of 

 the Department of Agriculture. 



Pre-eminent among individual observers is undoubtedly the late Herr 

 Gatke, of Heliogoland, whose observations cover a period of some fifty 

 years, while in this country Mr. Leverett M. Loomis has accumulated 

 a mass of notes on the movements of the water birds off the California 

 coast, and 'Sir. Otto Widmann has for years kept accurate records of 

 migration in the Mississippi valley, which are largely quoted by Cooke in 

 the work mentioned. Some information has also been gathered relative 



^Nature, X., p. 459. 



2 The Foundations of Zoology, chapter V. New York, 1899. 



3 Keport on Bird Migration in the Mississippi Valley in the Years 1884 and 1885, by 

 \Y. W. Cooke. Edited and revised by Dr. C. Hart Merriam. U. S. Dept. Agr., Division 

 of Economic Ornithology, Bulletin No. 2. Washington, 1888. 



*Reprinted from the Third Annual Report of the Michigan Academy of Science, for 

 3 901, pp. 67-70. Lansing, 1902. 



