1920] Swarth: Revision of Avian Genus Passerella 113 



species. These tracts aiford shelter for brush-loving birds, and it 

 might be supposed that they would be occupied by the winter visiting 

 fox sparrows; but such is not the case. In many years experience 

 in such surroundings, while quail shooting and bird collecting, the 

 writer has never seen a fox sparrow thus situated. In southern Cali- 

 fornia fox sparrows in general apparently occur but rarely in the 

 Lower Sonoran vallej^s. The brush covered hills. Upper Sonoran and 

 as far up as low Transition, is the favored winter habitat, with local 

 variations as elsewhere noted. 



In April, 1912, while the author was collecting at the eastern base 

 of the Sierra Nevada, near Lone Pine, Inyo County, fox sparrows were 

 observed migrating northward. All that were taken were schistacea, 

 the forms that nest in the adjacent mountains, mariposae in the Sierra 

 Nevada, and aanescens in the White Mountains, not being detected 

 in the lowlands at all. This fact, and also the non-occurrence of 

 stephensi in the foothills of the mountains wherein the latter breeds, 

 is, I believe, in each case, indicative of rather abrupt arrival at, and 

 departure from, the breeding grounds, with no tarrying in the low- 

 lands nearby; suggestive of just such migration, in fact, as has been 

 inferred on similar grounds in certain of the Alaskan subspecies. 



In September, 1916, in the Kings River Caiion, in the Sierra 

 Nevada, the first migrating fox sparrow was noted on September 10, 

 and several others w^ere observed during the next few daj's. Those 

 collected proved to be all schistacea, evidently from some point con- 

 siderably to the northward, and no specimens were taken of nmriposae, 

 the race breeding in the Sierra Nevada to the north and east of Kings 

 River Canon. No Passerella was found breeding on the floor of the 

 caiion. A few days later, at Horse Corral Meadow, on the adjacent 

 table land to the southward, fox sparrows of several subspecies were 

 found migrating abundantly. It seemed apparent that there was no 

 migration from the east to the west side of the Sierras, or vice versa, 

 in which the Kings River Caiion could be used as a highway, and this 

 was borne out by the manner of occurrence of many species of birds 

 besides the fox sparrows. It was also apparent that migrants were 

 travelling southward in numbers along the line of the Sierras, stopping 

 at favorable places along the higher ridges, but not descending, except 

 rarely, into the deep gorge that cut across their path. 



