12 THE CHICAGO ACADEMY OF SCIENCES. 



small woodland species during the breeding season. Although 

 birds are exceedingly numerous here during the migrations, and 

 the 'number of species found during summer compares favorably 

 with the number found at the same season in other localities hav- 

 ing the same latitude, they are represented by decidedly few 

 individuals. This fact is especially noticeable after one has 

 passed a day in the marshes of the vicinity, where the abundance 

 of numerous marsh and water birds, both in species and indi- 

 viduals, would lead one to suppose the woods were equally 

 favored." 



In connection with the study of the birds of this area, the 

 statement of Professor Henry J. Cox, Weather Forecaster of 

 this district is very interesting and useful. He says: "The 

 climate of Chicago is quite variable, as is characteristic of places 

 situated in the temperate zone, especially in the interior of the 

 United States. The extreme range of temperature during the 

 past thirty-three years has been 129 degrees, from a maximum 

 of 103 degrees to a minimum of 26 degrees below zero. This 

 variation, however, is not as great as what usually takes place 

 in other sections of the Northern States. Located as it is at the 

 southern end of Lake Michigan, the extreme heat of summer and 

 cold of winter are tempered by the waters bordering the city. * * * 

 In winter the influence of the Lake on the temperature is also 

 very great in producing equable conditions. The extreme rec- 

 ords in the interior are not approached along its shores." 



Professor Cox also says that this "area is not in the course of 

 any regular storm track, generally merely being on the edges 

 of the storms that pass to the north over Lake Superior or to 

 the storms that pass to the south over the Ohio valley. The 

 prevailing direction of the wind is southwest, for the year as a 

 whole. During the spring and early summer the wind is mostly 

 northeast." There are, however, at times brisk and sometimes 

 strong winds which are more beneficial than objectionable. 

 These conditions of weather are far from objectionable to the 

 birds, at least during their migrations. The area is also one that 

 is seldom visited by droughts or by protracted rain periods. 

 Especially pleasant weather in the autumn is one of the strong 

 points of this region, and is especially favorable to the fall migra- 

 tion of the birds. "It is the time of the year when rain is least 

 needed and when but little falls. It is the time of protracted 

 sunshine and delightful weather." It is not at all strange that so 



