V "'i'M:^ X | Cookb, Tht Relation of Bird Migration to the Weather. 221 



is s«t near LaCrosse thai the temperatures of the two places 

 were probably nol much different. The evening of March 28, 

 the temperature is lower than normal throughout the Mississippi 

 Valley. During the nexl day the temperature a1 both Keokuk 

 and St. I.onis rises above the normal bringing on a large migration 

 ;i( St. Louis with clear weather and a south wind all the way from 

 St. I ouis to the Gulf. 



The night of March -il is clear over all the Mississippi Valley 

 from St. Paul id the Gulf, with a lighl south wind from the Gulf 



to < aim, and a lighl ea. ,t and nori hca:.t wind the resl of the w ay to 



LaCrosse. The temperature at St. Louis is far above normal, 

 Keokuk, a little above, Davenport slightly below and LaCrosse 

 about five degrees below normal. Conditions for migration were 

 therefore very favorable from the south to about Keokuk and 



thence northward not unfavorable. Hence it may he considered 

 that these six species the Fox Sparrow, Brown Creeper, kuhy- 



crowned Kinglet, Yellow-bellied Sapsucker, Field Sparrow and 

 Purple Martin had arrived by the night of March '_'!) in southern 



Iowa (judging From the weather and from the notes contributed 



by the observers in low a I and during t he evening of March .'i I t hey 

 started north again. The individuals that were noted at Lanesboro 

 the morning of April I had therefore traveled the night before 



from a1 least as far south as Davenport and probably from 

 Keokuk. 



