1066 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



underparts are white. This description includes the races montanus, 

 shufeldti, thurheri, oreganus, and mearnsi. 



The tone of brown on the back, the yellow, buff or pink on the sides, 

 the tone of black on the head varying from gray to black, and their 

 dimensions help the museum worker distinguish one race from another, 

 but normally these characteristics are not to be relied upon for field 

 identification. A. H. Miller (1936) says: "I know of no one who 

 dares claim ability to identify as to subspecies a living, fidgeting 

 Oregon Jimco that he may be banding. Identified specimens readUy 

 available for comparison can increase a person's accuracy in such a 

 situation, but, even then, many errors will be made. * * * The most 

 detailed study of specimens of some of these races enables one to iden- 

 tify with accuracy only about eighty per cent of wintering birds. 

 Obviously, birds of all these races should be designated merely as 

 Oregon Juncos (J. oreganus) in field and banding work." 



The exception is the race mearnsi, formerly separated as the pink- 

 sided junco. Its sides are a rich pinkish cinnamon that often almost 

 meets across the breast, and its hood is a clear gray. 



Enemies. — The survival rate of juncos in the wild tells us that its 

 enemies are many. J. M. Linsdale (1949) and coworkers banded 233 

 Oregon juncos during an 11-year period beginning in the fall of 1937. 

 After 1 year 20 were again trapped, 19 were trapped after 2 years, 

 and retrapping success decreased until in the 8th year 1 bird 

 living for that length of time was retrapped. Thus one junco 

 lived at least 8 years after it was banded. 



Loye Miller's (1952) imitations of pigmy owl {Glaucidium gnoma) 

 calls at Saragossa Springs, San Bernardino Mountains, Calif., June 

 25, 1930, brought a quick response from a number of small birds 

 including Oregon juncos. Charles Michael (1927) wTites that after 

 a pigmy owl robbed a downy woodpecker nest of a practically full- 

 grown nestling, a pair of juncos and other small birds gave distress 

 cries and scolded the owl with no effect. All efforts by G. B. Castle 

 (1937) failed to make a pigmy owl drop a junco from its talons. 



Loye MUler (1952) observes that small passerine species do not 

 react to the larger owls, either by sight or by sound. H. S. Fitch 

 (1947) found the remains of a single Oregon junco among the 1,471 

 prey items he identified from 654 horned owl {Bubo virginianus) 

 peUets. 



A pair of Oregon juncos and several pairs of other smaU birds had 

 nests in the vicinity of a goshawk's (Accipiter gentilis) nest being 

 studied by James B. and Ralph E. Dixon (1938). The Dixons 

 write: "All of these birds had fear of the hawks * * * as shown by 

 the fact that the only way we could tell the old hawk was approach- 



