No. 500] MID-SUMMER BIRD LIFE OF ILLINOIS 517 



five kinds of birds in meadows, there were, in the northern 

 section, 25 of them in pastures, in the central section 41, 

 and in the southern section 32. The cause of this ap- 

 parent change in the preference of the meadow-larks of 

 central Illinois seems, therefore, something peculiar to 

 themselves, and is still to seek. 



Birds of the Pastures 



The birds of a given situation may be discussed from 

 two quite different standpoints, both interesting and 

 pertinent, and both really necessary to a complete under- 

 standing of the facts. We may consider the members of 

 an assemblage of species there with first reference to their 

 relative importance to the situation itself— with refer- 

 ence, that is, to their comparative numbers, or to the 

 nature and effect of their activities ; or we may consider 

 the situation with first reference to its relative importance 

 in the economy and life of each species of bird which in- 

 habits or visits it. If this situation is woodland, for 

 example, a bird found only in forests might, if a com- 

 paratively rare species, have very little importance- 

 might produce very little effect in the situation because 

 of its infrequent occurrence there, while to the species 

 itself the forest situation would be all-important, as the 

 sole place of its habitation. Its own significance in 

 forests might be easily overbalanced by a very abundant 

 species which should visit woodlands only occasionally, 

 but whose average numbers there might be twice or 

 thrice as large to the unit of area and time as those of the 

 less abundant species inhabiting forests exclusively. 

 Time will not permit me to illustrate this division of my 

 topic from both these points of view, and I will limit 

 myself to a few words in conclusion on the pasture birds 

 as a group and on some of the more prominent pasture 

 species with reference to their importance in pastures. 



Pasture lands were the preferred resort of our most 

 abundant mid-summer birds. That is, more birds were 

 seen in pastures than in any other of the larger crop areas 



