THE OOLOGIST 



21 



of different characteristics, ply tlieir voca- ' 

 tion upon different parts of the same tree, 

 each using its own peculiar way of captur- 

 ing its food. So thoroughly is this grand 

 principle carried out, that, infinite as the 

 number of trees and shrubs apparently is, 

 few or none whose appearance suggested 

 food have not at one time or another been 

 examined. The Woodpeckers, Nuthatch- 

 es, Creepers and Warblers are in majority, 

 for their services are required more than 

 those of other species, and each one in turn 

 may obtain his prey from the same tree, 

 since the wants and modes of pursuit of one 

 ai-e more or less different from those of the 

 others. Add to these the Flycatchers and 

 Thrushes, and we see that it is possible for 

 all to subsist in the same locality, however 

 numerous they may be. 



As to the utility of these birds whose of- 

 fice has just been briefly described, it may 

 be proper to say, that, to comprehend the 

 subject satisfactorily cannot but require a 

 life study of the birds and their surround- 

 ings, and no less attention to the entomol- 

 ogy of the locality. While it is reasonable 

 to consider insect life in some of its phases 

 and in some connections, highly deleterious 

 to vegetation, we should not be hasty to 

 conclude that the entire host belongs in the 

 same category. In viewing the contents 

 of a bird's crop or stomach, therefore, if 

 we find all insects and nothing else, we do 

 not in the examination, prove the bird a 

 benefactor by any means. Simply because 

 certain of these little animals are known to 

 be largely parasitic and profitable, and 

 some birds live upon these almost exclu- 

 sively. A requisition for the successful and 

 exhaustive pursuit of the sttidy, then, is 

 entomological knowledge. 



Some attention to the habits of the birds 

 we have mentioned, will show them to be 

 beneficial in nuiuy respects. We refer es- 

 pecially to the climbing birds, whose voca- 

 tion is to search the bark of trees for in- 

 sects. Repeated investigations have de- 

 monstrated that few or none of the insects 

 and larvae devoured by the climbers con- 

 tribute to the preservation of a tree, but by 



obtaining their subsistence from its sap and 

 vital parts, are highly destructive to it. 

 The Thrushes, unfortunately, must be class- 

 ed among those birds whose deep wood life 

 is seldom as detailedly given as should be 

 necessary for a thorough understanding of 

 their economy. That they perform an im- 

 portant part in the preservation of vegeta- 

 tion is evident, for they probably effect 

 more actual good in their sphere of search 

 than any of their co-laborers in the same 

 sphere — good, because a large proportion 

 of terrestrial insects undergo changes in 

 life during which vegetation is attacked for 

 food ; and it is these little destroyers which 

 the Thrushes feed largely upon, vmearthing 

 them from their homes among the roots of 

 plants and shrubs. It may eventually be 

 questioned whether or not it were better 

 these grubs and insects preyed upon the 

 great mass of small vegetation, injurious or 

 otherwise, but we are not prepared to ex- 

 tend this discussion into the province of 

 physics or into a series of illustrations of 

 natural economy. 



Exclusive mention of small birds has 

 thus far been made in this connection be- 

 cause they are the greatest insect eaters, and 

 the general utility of birds forms a part of 

 the subject only insofar as the destruction 

 of insects is concerned. But nearly all 

 species, even Hawks, waterfowl and galli- 

 naceous birds, eat insects, including cater- 

 pillars and worms ; the last mentioned or- 

 der are quite well known to be somewhat 

 insectivorous. Beetles and other large in- 

 sects, many of whicli are exceedingly per- 

 nicious, form no inconsiderable portion of 

 the diet of these species. The services ren- 

 dered by birds are, to use an oft repeated 

 expression, much greater than is generally 

 supposed ; and it should be worth while to 

 everyone, ornithologist or not, to carefully 

 weigh new evidence of a bird's usefulness 

 with its supposed evil qualities, and give it 

 credit for its jrood deeds. 



Do not fail to obtain our October 

 number ; it promises to be interesting. 



