TOWNSEND'S OREGON JUNCO 1091 



Granitic outcrops are frequent and, in combination with exposure, 

 are causes of the interdigitation of tracts of Upper Sonoran forest. 

 The junco habitat in summer is the parkUke yellow pine forest." 



The pontilis population is separated in the nesting season from the 

 nearest thurberi to the north in San Diego County, Calif,, by possibly 

 40 miles of unsuitable territory; the mountains are not high enough 

 for pine forest from 15 or 20 miles north of the boundary to 15 or 

 20 miles south. Similarly the decrease in height of the mountains 

 north and south of San Matias pass separates pontilis from townsendi 

 in San Pedro Mdrtir Mountain, the gap being 40 miles or perhaps 

 less. 



I have found nothing in the literature or by correspondence to 

 indicate any differences between pontilis and other Oregon juncos in 

 habits, beliavior, nesting, eggs, or other phases of life history. 



Joseph Grinnell (1928b) remarks that these juncos are "apparently 

 not very common." Perhaps the explanation comes from E. W. 

 Nelson (1922), who says: "Water is scarce all along the summit of the 

 Sierra Ju^ez. The Hanson Lagoon (or Laguna Hanson), about 

 half a mile across, is the largest of several small shallow lakelets lying 

 on the highest part of the range northeast of Ensenada. A few very 

 small streams rise at the heads of gulches near the top of the west 

 slope and flow down to the lower border of the foothills * * *. 

 Water is still scarcer on the higher parts of the east slope than on the 

 west * * *." 



Fall and winter. — Other races of Oregon junco, particularly thurberi 

 and to a lesser extent shufeldti, winter within the range of pontilis. 

 Miller (1941b) says: "The fall-taken specimens all come from these 

 [Sierra Judrez] mountains. One bird was taken at an elevation of 

 4200 feet at Los Pozos about 30 miles north of Laguna Hanson, 

 October 31. There is no evidence of migration, therefore. There 

 may be some tendency, as in townsendi, to descend to lower levels in 

 winter." 



Distribution 



Range. — The Hanson Laguna Oregon junco is resident in the Sierra 

 Judrez (Los Pozos, Laguna Hanson) in northern Baja California. 



JUNCO OREGANUS TOWNSENDI Anthony 



Townsend's Oregon Junco 

 Contributed by James H. Phelps, Jr. 



Habits 



The isolated, even to this day. Sierra San Pedro Mdrtir of Baja 

 California, Mexico, is the home of the southernmost member of the 



