RELATIVE ABUNDANCE. 5 



patient search. Additions to this list would be gladly re- 

 ceived. 



Relative Abundance. 



In speaking of the relative abundance in Ohio of the sev- 

 eral species of this catalaogue I have made use of the more 

 than threescore reports contributed by bird students scat- 

 tered over most of the state.' None of these reports give 

 evidence of any more system in determining the relative 

 abundance than Dr. Wheaton's and his colaborers' work 

 shows, hence the comparisons drawn will seem fair. It is 

 to be hoped that some system for the determination of the 

 relative abundance of birds may soon be brought forward; 

 until that is done we cannot hope for accurate results in this 

 field of knowledge. Dr. Wheaton's observations and those 

 of the persons on whom he relied for information covered 

 only a small fraction of the state, to be sure, but the regions 

 covered may be assumed to have been representative of most 

 of the state at least. It will appear in the discussion of this 

 interesting subject that the author has often quoted him- 

 self without the mention of others. Where that is the case 

 the reports received from observers have been too conflict- 

 ing to be of use, and he has been driven from the unknown 

 to the known. The necessary differences prevailing among 

 bird students as regards the time spent in study, the time 

 of day when the observations are made and the topography 

 covered, furnish no means of comparison unless these ele- 

 ments are known. P'ield work done at noon only will fail 

 to discover such birds as are quiet during that time. Field 

 work which does not cover certain regions will result in 

 omitting such species as resort only to such regions. Unfa- 

 miliarity with notes and songs will often result in the failure 

 to discover certain secretive species, or will fail to notice 

 more than a few where there may be great numbers. Thus 

 it is that only where pretty general agreement obtains, or 

 where there is an evident gradation from one region to an- 

 other at some distance, that these reports can be wholly re- 

 lied upon. This does not mean that the accuracy of any ob- 



