t -^ BIRDS OF THE MOUXTAIX TOPS. 



sideration are not without special influence on avian life can scarcely 

 be doubted; and it seems highly probable that, in the case of several 

 species found about the summit referred to, and not elsewhere in the 

 same region, that their presence was due not alone to the altitude 

 per se but also to the collateral conditions above depicted. 



Passing up the mountain side few birds were observed, but when 

 the high ridge leading to the summit was gained their numbers in- 

 creased, and about the summit the following species were noted : 

 Olive-backed Thrush, Black-throated Green Warbler. 



Bicknell's Thrush, Mourning Warbler, 



Hermit Thrush, Purple Finch, 



Winter Wren, Red Crossbill, 



Black-capped Chickadee, Slate-colored Snowbird, 



Canada Nuthatch, Blue Jay, 



Brown Creeper, Yellow-bellied Flycatcher, 



Yellow-rumped Warbler, Hairy Woodpecker, 



Black-and-yellow Warbler, Red-tailed Hawk. 

 Black-poll Warbler. 

 It seems strongly probable that the presence of some of these birds 

 was o-overned, in a measure at least, by the dampness and humidity 

 of the situation. From what is known of the breeding habits of the 

 Black poll Warbler and the Yellow-bellied Fhcatcher, it seems evi- 

 dent that low swampy situations are their favorite haunts during their 

 season of reproduction; and it is probable that considerations of hu- 

 midity in surroundings influence, in a greater or less degree, others 

 of the species mentioned in the choice of a breeding resort. 



That so many birds should have found their way to so remote and 

 isolated a situation when it is not probable that all reached it by di- 

 rect migration, is an interesting fact, and may for a moment be 

 dwelt upon. In a recent paper by the writer'^' allusion is made to 

 the gradual awakening of the birds at the top of Slide Mountain. 



* Previously cited. 



