DISTRIBUTION OF THE EOCK WREN 161 



the " History of North American Birds" (1874), it is said to be 

 "not recorded from Pacific slope"; but one such record, of 

 date 1868, is above quoted. The current eastward limitation 

 of its range must likewise be extended, since the bird has been 

 found in Iowa. Yet authors are right in regarding it as more 

 especially or chiefly an inhabitant of the great central plateau 

 and Rocky Mountains at large to the Coast ranges; and I am 

 not aware that it has ever been found on the coast of Upper 

 (California or Oregon, though it is said by Dr. Cooper to appear 

 toward the Sacramento Valley. It gains the coast further 

 south, and extends to Cape Saint Lucas. Its northern limit is 

 close by the boundary of the United States (latitude 49°). In 

 the other direction, the matter is less defiuite. I give a Mexi- 

 can quotation in a preceding paragraph, and we have the ex- 

 cellent authority of Mr. Osbert Salvin for the occurrence of the 

 bird in Guatemala. Of the movements of the bird within the 

 general area of its distribution, I am not prepared to speak with 

 desirable precision. It is migratory ; but the northern limit 

 of its wintering, and the southern limit of its summering, I 

 think remain to be ascertained. It appears to breed at large 

 in its United States range. At Fort Whipple I noticed its 

 arrival during the latter part of April, and it remains there at 

 least until April. At Fort Mojave, lower in the Territory, 

 though near the same latitude, its presence has been noted in 

 February, and the inference is that it winters there. It has 

 been found at Toquerville, Utah, after the middle of October. 

 Some of its movements may be further illustrated by the fol- 

 lowing notes of Mr. T. M. Trippe, extracted from the " Birds of 

 the Northwest": — 



" The Kock Vv'ren arrives at Idaho [Springs, Clear Creek 

 County, Colorado,] about the 20th of May, and extends its range 

 up to, and a little above, timber-line. It breeds most abundantly 

 between 6,500 and 9,500 feet, rarely nesting higher than the 

 latter elevation, though found during summer from 12,000 feet 

 down to the plains. It is a constant resident of the piles of loose 

 rock which lie scattered on the mountain-sides, in which it finds 

 its food and rears its young, and to which it retreats for safety 

 on being alarmed. On its first arrival it is rather shy, but 

 soon becomes tame and even familiar, haunting piles of boul- 

 ders and small stones in the placer diggings, close to the miners' 

 cabins. It rarely ventures far from its favorite rocky retreats ; 

 but occasionally visits the road-sides to pick up flies and other 

 11 B 



