1060 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



collected an almost pure male albino, mated to a normal female, near 

 Beaverton, Oreg., some time in May 1885. Anthony had noticed the 

 bird the year before but was unable to secure it; local residents told 

 him the albino had been present at least two breeding seasons before 

 Anthony first saw it. 



Hybridization and inter gradation. — The races montanus and mearnsi, 

 the latter at one time separated specifically as the pink-sided junco, 

 intergrade. The races montanus, shyjeldti, and oreganus intergrade; 

 shufeldti and thurheri intergrade; thurberi surrounds in range and 

 intergrades with, pinosus. The resident races of Baja California, 

 pontilis and townsendi, are not known to intergrade or hybridize 

 with other juncos. 



The race thurberi hybridizes with the gray-headed junco {Junco 

 caniceps) as does the race mearnsi. This is discussed in the species 

 account of the gray-headed junco. 



Hybridization between the slate-colored junco (Junco hyemalis) 

 and the Oregon junco {Junco oreganus) is likely whenever a jimco of 

 one species in breeding condition finds itself surrounded only by 

 juncos of the other species, also receptive. As individuals of each 

 species may be found well ■\^dthin the range of the other, it follows 

 that a wide scattering of hybrids does occiu*. When the two inter- 

 breed the color areas of the side, back, and liead are modified, and 

 every degree of mixture in plmnage can be found. For a full dis- 

 cussion of the relationships betweenjthe different^ juncos, see A. H. 

 Miller (1941b). 



Food. — G, W. Salt (1953) aptly classifies the junco as a "ground- 

 seed forager," Seeds of many plants are the main food of the Oregon 

 junco. Weed seeds and waste grain are important during fall and 

 winter. Insects are eaten when available and are important food 

 during the nesting season. A. C. Martin, H. S. Zim, and A. L. 

 Nelson (1951) say: "Beetles (especially weevils), ants, caterpillars, 

 grasshoppers, leafhoppers, together with some spiders, wasps, and 

 flies are the chief items in the animal diet of this junco." 



F. E. L. Beal (1910) analyzed the contents of 269 Oregon junco 

 stomachs, most of them taken in fall and winter. His first analysis 

 "gives 24 percent of animal matter to 76 of vegetable." His state- 

 ment about animal food, mostly insects, agrees well ^\ith the state- 

 ment of Martin, Zim, and Nelson. Beal adds: "Caterpillars are 

 apparently the favorite insect food, forming 9.4 percent of the diet." 

 Weed seeds are eaten in every month and on a yearly basis amount 

 to 61.8 percent of the food, in September nearly 95 percent, 



G. F. Knowlton (1937b) reports the contents of 25 stomachs from 

 Oregon juncos as follows: "180 Homoptera in 18 stomachs, composed 

 entirely of 13 adult and 167 nymphal beet leafhoppers in 12 stomachs; 



