^ORNITHOLOGIST 



OOLOGIST. 



$1.50 per 

 Annum. 



FRANK B. WEBSTER, Publisher. 

 Established, March, 1875. 



Single Copy 

 15 Cents. 



VOL. X. 



PAWTUCKET, R. I., JANUARY, 1885. 



No. I. 



Mississippi Valley Migration. 



BIRD WA VES. 

 BY PKOF. \V. W. COOKE, jMOOIillEAD, MINN. 



The idea of studying the bird waves was not 

 thougUt of until mignition last Spring had fairly 

 coraraeiiced. No instructions were issued to the 

 observers to note bird waves and only a few sent 

 any specitic notes on the subject. Under such 

 adverse conditions, there would have been no at- 

 tempt to write up the waves, were it not for the 

 e.xtrenie importance of tlie subject. It is during 

 these nights of bird waves that the bulk of migra- 

 tion occurs. This is esi)ccially true of Fall mi- 

 gration, but also to a large e.xtent in the Spring. 

 If then, we are to study migration successfully, 

 we must study it when it is most active. More- 

 over, it is on bird waves that the action of the 

 weather is most apparent, hence they furnish the 

 readiest means for studying the relation between 

 meteorology and migration. 



The great drawback is the difficulty of accu- 

 rately observing and reporting the bird waves. 

 It is by far the hardest part of the field work in 

 the study of migration, and requires more time 

 and a more constant presence in the field than 

 most observers can give. 



The word " bird waves" has been used many 

 times, but no meaning has been given to it. 

 There are indeed, two meanings and two modes 

 of study. We may consider a bird wave as an 

 unusually large number of birds which, during 

 one or more days, spread over a portion of our 

 district. 



Viewed in this light, the work before us is to 

 ascertain the several species of birds constituting 

 the wave, and the boundaries of the territory 

 over which it passed. 



Or, having learned that certain species were 

 migrating together on a given day, we may con- 

 sider these species as a wave and watch their 

 northward progress day after day and week after 

 week, now stopping or receding before the breath 

 of a fierce norther, and now urged rapidly for- 



ward by the gentle south wind, until they reach 

 their Summer homes in the far north. 



It is this second method which we will now 

 employ, but it is applicable only to the earliest 

 waves. It is only early in the season that these 

 species which are together in the south keep to- 

 gether during their entire journey. In all the 

 later waves the species migrating together change 

 constantly from day to day. 



The first wave last Spring consisted principally 

 of Ducks, Geese, Blackbirds, Larks, Killdeer, 

 Robins and Bluebirds. After being driven south 

 by the extreme cold of the first week in January, 

 they returned to St. Louis, 38*», on January 31 ; 

 but went no farther, nor was au}^ advance move- 

 ment made until February 25, when a small por- 

 tion moved one degree farther north. Then 

 came a total standstill until March 10; but the 

 fid I influence of the warm weather was not felt 

 until the 13th to IStli of the month. The period 

 fi-om March 10 to 16, was one of great activity. 

 During this time the liirds of the first wave spread 

 over the whole northern half of Illinois, the 

 southern edge of Wisconsin, the whole of Iowa 

 and Nebraska, while .scouts followed up the 

 Mi.ssissippi River almost to St. Paul. During 

 the ne.xt few days, from March 17 to March 31, 

 the advance was continued and the birds visited 

 all the country to latitude 44°, with a few irregu- 

 lar appearances at points half a degree farther 

 north, and one impetuous Goose clear up to St. 

 Ansgar, Dak., 46°. By March 26, they have 

 been reported from every station to 46°, with 

 scouts of Ducks and Geese hunting up the Mis- 

 souri and Red Rivers, almost to 48°. 



From here northward, the observers are few 

 and confined to the valley of the Red River of 

 the north. Judging by the reports, it would 

 seem that by this time the different species of the 

 first wave were beginning to be widely .separated. 

 The Bluebird has fallen out entirely since we left 

 latitude 45°; the Robins and Blackbirds still move 

 onward, but they are several days behind the 

 Ducks and Geese. The latter crossed the bound- 



Copyright, 1885, by Frank B. Webster and Eaton Clipi-. 



''\ 



