A. 



.^ 



ORNITHOLOGIST 



AND — 



OOLOGIST. 



$l.')i^ per 

 Annum. 



FRANK B. WEBSTER, Publisher. 

 Established, March, 18T5. 



Single Copy 

 l.'j Cents. 



VOL. X. 



PAWTUCKET, R. I., FEBRUARY, 1885. 



No. 2 



Migration in the Mississippi Valley. 



THE UELA riOS OF MIliliA T[OS TO A TMOSI'llKIUC 

 WAllM A.\D COLD H'.ir^.s. 



IIV riKlF. \\ . \V. ( OOKE, MOOnirEAD, MINN. 



riKi'i.ic Mahtin. (f'mgne siibis,}. This species 

 will lie tivalcd villi reference to tbe influence 

 uliicli the MliniisiiliiTlc wiirm and cold waves had 

 uiion its niovemcMls. If we study the reports of 

 I lie Signal Service we will find tluit tliere is a suc- 

 cession of cold and warm waves passing over our 

 district. They liegin in the northwest, or in the 

 Koclcy Jlounlains, pa.ssing eastward and south- 

 ward. This is true of the warm waves as well as 

 I lie cold. The common idea that a warm wave 

 lii'j;ins ill llic sniilli and passes northward is 

 wi-diij;-; il lii';;iiis in the iiorlli and passes .south- 

 ward. To lake a coiurclc e.\aiiii>le, on the night 

 of April 'i'ii, 1884, a warm wave began at Custer, 

 ill the IJocky Mountains. At 11 p. m., the tein- 

 pcrature was (^'d\ while at Memplii.s, Tenn., 

 several liuiidrcd miles farther soutli and east, it 

 was l.T eolder, the mercury standing at 48°. This 

 warm wa\c rc.iclicil llie Missouri River at Yanlc- 

 lon and < )iiialia on llic night of April 3oth; the 

 .Mississippi at Ki'oU\ik and St. Louis on the 26th; 

 the next niglil it is shown in tlie records at Cairo 

 and ,Mciiipliis. while the nia.ximum lieat is not 

 reached ,il N'iek.-lairi;' \nitil the night of the 28tli, 

 Tims lliis warm wave occu|)ied five days in pa.s,s- 

 iiii; rrcim Ihc Ixocky Mountains to Vick.sliurg. 

 licfuic lliis. on llie 2Ttli, a cold wave liad alreadj' 

 sinicU Cusicr. reducing the temperature to 35°: 

 and this lold wave also passing south and east, 

 reached Viiksliiirg the next night after the warm 

 w.ivc. Ill lliis way, wavesarc constantly pas.sing, 

 • iiiil lliiir iiilluiniT nil the migration of birds is 

 very marked. Selilnni, if ever, will a bird at- 

 lempl to move agaiiisl a well pronounced polar 

 wave, while Ihe night of maximum heat, otiier 

 conditions l)eing favoralile. is Ihe time when Ihe 

 greatest movement will be made. 



These facts having lieen thoroughly proved liy 

 llic niDiils of last Spring's migration, let u.s note 



their hearing on the sl\idy of Ihe notes as con- 

 tril)uted. We find in Ihe record of any one of 

 the more common species, first, certain notes 

 whidi are self-evident mistakes; these we throw- 

 out ; second!}', we find a numljer of records, vary- 

 ing from ten to thirty per cent, of the whole num- 

 ber contributed, stating that the tir.st or Imlk of 

 the species arrived during a night wdiich was the 

 minimum of a cold wave. AVhal shall we do 

 with such records? often the liiiih standing of 

 the observer precludes llie iiossibilily "f a mis- 

 identification, and even a wrong name would not 

 help us out of the difficulty. The probabilily is 

 that in seven or eight cases out of tei', the birds 

 actually came during the preceding warm wa\e. 

 and were unnoticed until several days after their 

 arrival; the other cases lieing tho.se in wliich a 

 species, starting to migrate under favorable 

 auspices the early part of the niglit, is overtaken 

 en i-oute by a storm and forced to seek the 

 nearest shelter; or those cases, toward the latter 

 end of migration, when even llie comparatively 

 cold waves do not reduce Ihe teni|ieralure suili- 

 cientl_y to stop migration. 



The rest of the notes group Uiemselves princi- 

 pally around tlie maximum of the warm wave; a 

 large munber exactly on the night, some one day 

 before and some the day after. Out of a list of 

 some six hunih-ed notes, not .selecWd but taken, 

 just as il happened, and studied with special 

 reference to the waves, it was fovuid that about 

 seventy-five (icr cent, as many movemenis were 

 recorded for the niglit before the maximum, as 

 for the maximum night, showing that the binls 

 made much use of this night for migration. We 

 arrive at the same conclusion if we study tlie 

 record of the single station at St. Louis, Here we 

 find tliat the great movements of the birds, the 

 local liird waves, are about evenly divided be- 

 tween the maximum and the night previous. 

 Some would therefore say llial tlie birds foresee 

 the approaching atmospheiie warm wave and mi- 

 grate accordingly, but probably a better state- 

 ment would be that increasing warmth becomes 



Copyright, :685, by Fkank B. Webster and Eaton Cliff. 



ff DEC 5 IP; 



