52 The Wilson Bulletin. 



Bald Eagle, 2; at their eyrie near Oak Point. 



Great Horned Owl, 2; in two deep woods, southeast and 

 northeast of Oberlin. 



Bronzed Grackle, 1 ; in Oberlin. 



Northern Shrike, 4; as already given. 



Carolina Wren, 3; as already given. 



Robin, 1; in Oberlin. 



Of the remaining 44 only averages for these five routes 

 can be given. But the work done outside of these routes 

 proves that they are fairly representative of all of the terri- 

 tory covered, and so represent the average bird population 

 for any given region of like extent in this part of the county. 

 There is little reasonable doubt that the whole county is 

 also fairly represented in this region. There may be deeper 

 and more extensive woods in the eastern part than we know 

 here, but there is certainly not more coniferous timber, nor 

 more favorable places for a large percentage of the birds. 



It is needless to say that there is here no basis for any 

 sort of an estimate of the whole bird population of the 

 county. All that can be said is that anywhere in the county 

 one might expect to find an equal number of birds under 

 equal conditions. The territory covered is far too little in 

 proportion to the whole to state more than this. But there 

 is one important consideration which this censo-horizon 

 work leads to. It is the possibility which it holds out for a 

 solution of the perplexing question of the meaning of the 

 commonly used terms "common," "rare," "abundant," etc. 

 It affords a basis for assigning definite values to these terms. 

 But that is a task fir too great to be adequately considered 

 as an incidental part of another paper. It is deserving of a 

 separate paper, which I hope may be forthcoming at no dis- 

 tant day. Until these wholly indefinite terms can be given 

 some definiteness, can they be used to convey any intelli- 

 gence to others than those who personally know the region 

 spoken of. 



The smaller land birds, at least, are gregarious to a greater 

 or lesser extent. Some are naturally gregarious within the 



