POINT PINOS OREGON JUNCO 1087 



The only suggestion that Point Pinos Oregon juncos have more 

 than one brood is the remark by Grinnell and Linsdale (1936) that: 

 "In one instance a nest was built in a tree, apparently by the same 

 pair which had just brought off a brood from a nest on the ground." 



Eggs. — H. B. Kaeding (1899) writes that the nest and eggs of the 

 Point Pinos Oregon junco apparently do not differ from those of the 

 Sierra or Thurber juncos. The normal clutch of eggs is four, but 

 one of the 24 nests found by Grinnell and Linsdale (1936) at Point 

 Lobos had a set of five. Another had three normal-sized eggs and 

 one not more than half the normal size; at a later date three young 

 were seen in the nest. 



Young. — Joseph DLxon (1924) writes that the nest he found was 

 completed and the first egg laid on Mar. 23, 1923: "At 6 o'clock on 

 the evening of March 26 the nest contained four eggs which the female 

 had begun to incubate. 



"At 9 A.M. on April 9 the nest contained two eggs and two young 

 wliich had hatched since the previous evening. Only two out of 

 the four eggs hatched. The fledghngs left the nest on April 16 when 

 only seven days old. They were not at that time able to fly, but 

 scrambled about readily beneath the tangled ivy and eluded my 

 grasp easily." Dixon's dates indicate about 13 days were needed 

 for incubation. He attributed the early departure of the young 

 to numerous "Argentine ants" in the nest. 



Plumages. — In his original description Loomis (1893) gives the 

 following characteristics: "Most nearly like * * * thurberiy but 

 throat, jugulum, and fore breast slate-gray, varying to dark slate- 

 gray, and upper portions of head and neck slate-gray, varying to 

 blackish slate; bill averaging broader and longer." 



Hybridization and inter gradation. — Grinnell and Miller (1944) say 

 this race: "Intergrades with J. o. thurberi in Marin and San Luis 

 Obispo * * * counties." Miller (1941b) notes the Marin wood- 

 lands, across the Golden Gate north of San Francisco, are separated 

 from the southern limits of thurberi breeding range along the Russian 

 River in Sonoma County by about 20 miles of countryside not suit- 

 able for breeding juncos, and: "A similar gap separates the breeding 

 areas north and south of San Francisco Bay. The isolation afforded 

 does not appear great, but in resident populations it means much 

 more than in migratory races." 



The intergrades between pinosus and thurberi show mixing or 

 blending of head, side and back color, and intermediacy in tail pattern 

 and measurements. 



Food. — The remarks in the main species account quoting the work 

 of F. E. L. Beal (1910) on food habits of juncos in California apply 

 in great part to this race. Beal ^vrites: "It would be better to treat 



646-737— 68— pt. 2 32 



