22 8 THE AMERICAN MIDLAND NATURALIST 



experience, which covers a period of about fourteen years; then I 

 shall state the results that were obtained by young men and boys 

 who did some observing under my direction. 



During the years I have been studying birds, I have never made 

 it a practice to do any shooting for the purpose of identifying them. 

 And I think I have successfully identified 156 species, among which 

 are the following: Rusty Blackbird, Acadian Flycatcher, Franklin's 

 Gall, Montana Junco, Bullock's Oriole, King R&il, Solitary Sand- 

 piper, Pine Siskin, Henslow Sparrow, Rough-winged Swallow, 

 Gray -cheeked Thrush, Blue-headed Vireo, Golden winged Warbler, 

 Orange-crowned Warb'er, Sycamore Warb'er. If 1hese species — 

 some of them very difficult to observe — could be identified without 

 killing, I should like to ask why cannot all other species be iden- 

 fied in the same manner? 



L,et us look more particularly at some of the species I have 

 mentioned, and see in what way they may be identified without 

 killing. One means is the process of elimination. We will take 

 first the Rusty Blackbird. Now, I will suppose that I already know 

 three species of black-birds — the Red- winged Blackbird, the 

 Cowbird and the Bronzed Grackle. What possible species remain 

 for this locality (northern Indiana) ? There are two — the Yellow- 

 headed Blackbird and the Rusty Blackbird. If I should see a 

 specimen of either of these blackbirds, certainly I could readily 

 distinguish them from each other; and I could also as easily separate 

 them from the species I already know. Does it not, then, seem 

 reasonable to say that I can be absolutely sure of my identification 

 of either of these two species of blackbirds? 



But let us take a more difficult case — the Acadian Flycatcher. 

 The flycatchers I have already identified (I will suppose) are the 

 Phoebe, Wood Pewee, Crested Flycatcher, Kingbird, Alder Fly- 

 catcher and Yellow-billed Flycatcher. Of those th it may possibly be 

 found there remain but two species — the Olive-sided Flycatchei 

 and the Acadian Flycatcher. These two species may be less easily 

 distinguished than were the two kinds of blackbirds described 

 above. Still I think that by learning all I can in books about the 

 markmgs and the habitat of these two flycatchers, I shall not have 

 any doubt as to their identification when I see either of them. As 

 a matter of fact, when I enter a rather deep wood with considerable 

 undergrowth, I am likely to hear an unfamiliar note. Probably 

 the dense growth of the trees and bushes will make it a very 



