iSirli-tore 



A BI-MONTHLY MAGAZINE 

 DEVOTED TO THE STUDY AND PROTECTION OF BIRDS 



Official Organ of the: Audubon Societies 



Vol. IV May — June, 1902 No. 3 



The Increase of the Chestnut-sided Warbler 



BY A. RADCLYFFE DUGMORE 



With photographs from Nature by the Author 



ANY one who observes the birds of a locality for many years in succes- 

 ^^j^ sion will notice that certain birds become more abundant, and 

 others less so, as years go by, and that while one bird will be very 

 common for several years, there will perhaps be a year when this particular 

 species will be comparatively scarce. In the region about South Orange, 

 New Jersey, particularly the part known as the 'Mountain,' the Field and 

 Song Sparrows are usually very abundant during the breeding season, but 

 last year (1901) they were scarcely as common as the Blue-winged 

 Warblers and Maryland Yellow-throats. Brown Thrashers, also, were 

 less common than they have been during my stay in South Orange; while 

 Indigo Birds, Ovenbirds, and several other species were remarkably com- 

 mon. But what has been most noticeable about the bird -life of this par- 

 ticular locality is the rapid and steady increase of the Chestnut -sided 

 Warblers. It has been interesting to watch the increasing number of 

 these delightful birds. In the summer of 1897, the first year that I did 

 any systematic bird work in this locality, these birds were so little in evi- 

 dence that I did not observe a single specimen. That they might have 

 been there is, of course, more than probable, but tiiey must have been 

 extremely scarce, for during the breeding season 1 spent a good deal of 

 time in likely places and yet never even heard their song, which is quite 

 conspicuous whenever the bird is nesting. 



The following year, in a certain large clearing (about a ciuarter of a 

 mile square) that is well covered with thick umlerbrush and a young 

 second growth of chestnut and oak, I noticed one pair on Ma\ i. Fhe 

 male bird was then in full song, and three weeks later the birds had com- 

 menced building. During this same summer I saw one pair in another 

 clearing that was situated within half a mile of the place in which I hail 



