OREGON JUNCO 1067 



iiig the nest was by the alaiTa notes these various birds sounded 

 before the hawk appeared upon the nest." 



Stomach analyses and personal observations of J. A, IMunro 

 (1929b) in British Columbia record the Oregon junco as being prey 

 to the sharp-shinned hawk (Accipiter velox) and the black pigeon 

 hawk {Falco c. suckleyi) . 



Cowbirds rarely parasitize the Oregon junco, for they seldom invade 

 its usual nesting habitat. Ian McTaggart Cowan (1939) records 

 one instance of the brown-headed cowbird {Molothrus ater ohscurus) 

 parasitizing the nest of an Oregon junco {J. o. montanus) at Tupper 

 Lake, Peace River, British Columbia, May 20, 1938, The nest was 

 later deserted. Friedmann (1963) reports another from the files 

 of the British Columbia Nest Records Scheme, "a nest with 4 eggs 

 of the junco and 1 of the cowbird, found 35 miles south of Vernon, 

 Okanagan Lake, June 17, 1959." 



Allen Mcintosh (pers. comm. to Oscar M. Root) lists the folloA\T.ng 

 genera of parasites of the Oregon junco: Isospera, D(Lsypsyllus, Eus- 

 choiKjastia, Omithomyia, Ricinus and Physostomum. R. O. Malcom- 

 son (1960) specifically hsts : Penenirmus mirinotatus, Ricinus hastatus, 

 and R. pallidus. Oregon jmicos were among the birds Don Bleitz 

 (1958) found infected A\ith foot pox, a vkal infection called avian 

 lymphomatosis. 



John J. WiUiams (1900) teUs of young juncos just out of the nest 

 preyed upon by a "mediiun-sized chipmunk," not other\\'ise identi- 

 fied. From the efforts passerine birds make to drive chipmunks 

 from the vicinity of nests, Williams assumes predation by chipmunks 

 to be significant. Lyman Belding (1901), early daj^ California orni- 

 thologist, did not agree, saymg: "I have seen at least a hundred 

 nests of the junco and can only remember one that was distm'bed bj'- 

 bird or animal, the exception being a nest that contained four yoimg 

 which were killed by a gopher snake." Carl Sharsmith (1936) ac- 

 cuses the Belding groimd squirrel (Citellus b. beldingi) of a carnivorous 

 diet on occasion, and mentions it killing the junco. 



J. M. Linsdale (1931) cites an example of the Oregon jimco being 

 poisoned by grain placed for rodents, in this instance hulled barley 

 treated with thaUiiuu. 



Certainly the environment must also be considered. Juncos nest- 

 ing at high elevations in the mountains suffer from sudden or late 

 season storms. A. IvI. Ingersoll (1913) tells of severe Jime storms 

 in the Sierra Navada of California. He woites: "AU new snow 

 that fell on Jime 23 [1912] melted away uithin forty-eiglit hoiu-s. 

 Two nests that held eggs when discovered were later found to contain 

 dead nestlings. Two nests held dented and cracked eggs after the 

 snow. One nest and five young were destroyed by some mammal 



