THE TIMBERLINE SPARROW 



A NEW SPECIES FROM NORTHWESTERN CANADA 



By HARRY S. SWARTH and ALLAN BROOKS 



(Contribution no. 442 from the Museum of Vertebrate Zoology of the University of California) 



DURING the summer of 1924 the two authors of the present paper were collect- 

 ing birds together in the Atlin region, in the extreme northwestern corner of 

 British Columbia. One of the most interesting of our finds was the discovery, 

 in the higher parts of the mountains of that region, of a Spizella apparently distinct 

 from any other known species. This bird is closely similar to Spizella breweri in 

 general appearance, but it differs appreciably from breweri in details of structure and 

 coloration. This northern Spizella we propose to name 



Spizella tavemeri*, new species 



Timberline Sparrow 



Type. — Male adult; Museuni of Vertebrate Zoology, no. 44856; Spruce Mountain, 

 at 5000 feet altitude, 10 miles east of Atlin, British Columbia; August 8, 1924; col- 

 lected by H. S. Swarth; original no. 13048. 



Diagnosis. — Most nearly like Spizella breweri. Slightly larger, with (usually) 

 rather longer tail, and with weaker, more slender bill. Coloration darker than in 

 breweri, with heavier streaking on top of head and back, darker flanks, and a tendency 

 toward the development of narrow streaks on breast and flanks. Bill and feet darker 

 than in breweri: "bill black at tip; upper mandible brownish, lower mandible flesh; 

 feet pale drab, tarsus brownish flesh" (Brooks' field notes). 



Specimens examined. — ^Adult male, 3; adult female, 4; immature, first winter 

 plumage, 4; juvenal, 6; molting from juvenal to first winter, 6. Total, 23. 



It seems best to accord this form specific standing, rather than to regard it as a 

 subspecies of breweri. The characters of taverneri seem constant. At any rate, in 

 the series at hand there is none that could be confused with breweri, and in extensive 

 series of breweri (numbering some hundreds of skins, from many localities) we have 

 found no specimen of equivocal character. The difference in bill alone seems diag- 

 nostic. This member is slender and dark colored in taverneri, relatively stubby and 

 pale colored in breweri. In the dried skin this feature is retained to its full extent, 

 so that the darker bill of a specimen of taverneri appears in strong contrast to that of 

 any breweri with which it is compared. 



♦ Named for P. A. Taverner, Ornithologist, Canadian Geological Survey, Ottawa, Canada. 



