12 BIRDS OF ILLINOIS. 



species during the breeding season. Although birds are exceedingly 

 numerous here during the migrations, and the number of species 

 found during the summer compares favorably with the number found 

 at the same season in other localities having 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 individuals, would lead one to suppose the woods were 

 equally favored. 



"The limits of the field discussed in this paper embrace two 

 counties, Cook county upon the south, and Lake county upon the 

 north. Each possesses certain topographical peculiarities. Cook 

 county is mainly prairie land, interspersed with ridges and groves 

 of timber, the former of which generally extend parallel to the lake 

 shore. Near the southeastern portion of the county the surface of 

 the prairie is but slightly above the level of the lake. Through this 

 county flows the Calumet river, along which are extensive marshes, 

 which form a favorite haunt for various waterfowl. Along the lake 

 shore, in northwestern Indiana, extending thence slightly into 

 Illinois, is the Pinery, a peculiar, sandy, barren tract of land partly 

 covered by a sparse growth of pines and deciduous underbrush, with, 

 near the lake, patches of juniper. Lake county has much more 

 woodland, and is more hilly or rolling than Cook county. Extend- 

 ing along the lake shore, from the northern border of the State 

 nearly the entire length of this county, is a tract quite similar to 

 the Pinery before described, except that here the sandhills near the 

 lake are nearly covered with the junipers (Juniperus communis). 

 Throughout this county are scattered a large number of small 

 lakes, many of which have a marshy border and are much fre- 

 quented by waterfowl, both during the migrations and the breeding 

 season. 



"The woods near Lake Michigan, in both these counties, are upon 

 ridges extending parallel to the lake shore, which are separated by 

 belts of prairie. These ridges form convenient highways for the 

 woodland species during the migrations. The water birds either 

 follow the lake shore or the river courses. The migrations of the 

 latter are almost directly north and south, but with the woodland 

 species it is quite different. They follow the heavily wooded river 

 bottoms from the south, and approa.cn the sparsely wooded States 

 along the upper Mississippi in immense numbers, where they swerve 

 toward the heavily wooded region of the northern lake region, where 



