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494. Dolichonyx oryzivorus (Linn.). [257.] Bobolink. 



A common migrant in the Mississippi Valley, breeding from Kan- 

 sas and Illinois northward. In 1884 fifty-four notes were furnished on 

 this species. Studied with relation to the warm and cold atmospheric 

 waves, in the same way that was done in the case of the Kingbird (see 

 pages 142-147), it is found that just 50 per cent, of the records are 

 bad — that is, they agree with the cold wave instead of the warm; 11 

 per cent, are indeterminate, and only 39 per cent, agree with the maxi- 

 mum of the warm wave. Why it should be thus is not known, though 

 the fact that the bird frequents marshy meadows, and hence is less easily 

 noted, may partially account for the difference. 



Wintering south of the United States, the earliest record of its ap- 

 pearance was from Saint Louis, where it arrived April 29. The notes 

 from Illinois are of no value. Bobolinks were noted at latitude 43° 06' 

 in Wisconsin, May 1; the bulk reached latitude 43° 20' in Wisconsin 

 with the next wave, May 5 ; while with the following wave, May 11, 

 the first reached latitude 44° 26', the bulk following on the 18th. West 

 of the Mississippi the movements agree a little better with atmos- 

 pheric waves. After reaching Saint Louis, April 29, the next wave 

 brought them at latitude 40° 50' in Iowa, May 3, and latitude 42° 01' and 

 latitude 42° IS 7 in Iowa, May 5, while arrivals at latitude 43° 48' and 

 45° 25' in Minnesota were noted the day after the maximum wave, on 

 May 10. The movements of the bulk averaged about ten days in the 

 rear of those of the van. 



On the prairie the maximum wave of the night of May 9 brought 

 them to latitude 40° 53' in Nebraska and latitude 41° 2 L ; in Dakota. 

 They reached latitude 4G° 58' in Dakota May 17, and May 23 were 

 noted from latitude 50° 30' in Manitoba. 



In the fall of 18S4 the first Bobolink at San Angelo, Tex., was seen 

 October 2, and at Abbeville, La., one was reported August 4. 



In the spring of 1885 the earliest record came from Mount Carmel, Mo., 

 April 20, but it was not again seen there until May 1. In the meantime 

 it had been seen at Saint Louis, Mo., April 28. A few stations in 

 northern Illinois reported Bobolinks May 5 and 6, but the pronounced 

 movement did not take place until May 10 to 12, during which three 

 days the species spread from southern Iowa to latitude 45° in Wiscon- 

 sin and Minnesota, and to Huron, Dak., latitude 44° 21'. They reached 

 Argusville, Dak., May 14; Menoken, Dak., May 15, and Shell Biver, 

 Manitoba, May 18. In the fall of 1885 the last Bobolink was reported 

 from Elk River, Minn,, September 3; Fern wood, 111., September 20 and 

 Grinnell, Iowa, July 27. 



494 a. Doliclionyx oryzivorus albinucha Eidgw. [ ] Western Booolinlc. 



The western race of the Bobolink is found from Dakota to Utah and 

 Nevada, and north into western Manitoba, where it was reported as an 

 abundant summer resident. 



