1064 U.S. NATIONAL MUSEUM BULLETIN 237 pabt 2 



never scratched in a mineral soil bed, although there was invariably 

 a wealth of seeds less than a quarter of an inch below the surface." 

 Seeds of western white pine were planted in the northwest corner 

 of the different seed beds, and the certainty which the birds showed 

 in flying from one northwest corner to another for their favorite seed 

 indicated to Ellison "a surprisingly exact memory for places." Ellison 

 concludes: 



Apparently [the juncos' intelligence] functions expertly within tlie limits of ordi- 

 nary circumstances, as illustrated by their returning so accurately to the food 

 source, and scratching among leaf-litter. Such stimuli and reactions are within 

 the realm of the birds' experience. But when extraordinary conditions obtain — 

 and the presence of forest seed buried in exposed soil is probably extraordinary, 

 compared to its common presence on the soil surface or buried in duff — their 

 intelligence does not turn those conditions to advantage. 



Moreover, that they did not show any interest in the soil surfaces after the 

 surface seed had been picked oft (although they returned for the attached seeds 

 once the seedlings had broken ground), makes it seem probable that juncos do 

 not detect such seed by smell, but by sight alone. 



To study the winter society of the Oregon junco, Mrs. Winifred S. 

 Sabine (1955) marked individual juncos by rubber cementing dif- 

 ferent combinations of trout-fly feathers to the top pair of the birds' 

 tail feathers close to the body. Some members of the flock could not 

 be caught, but enough were marked to simplify the problem and 

 reduce the number of possible errors. She observed the juncos over 

 a prolonged period as they frequented different feeding stations. 



Her studies suggest the social activities of the winter society in- 

 volve an orderly but rather complex type of flocking. She says 

 (1956): "Although the migrant individuals which are to become per- 

 manent residents arrive irregularly over a period of several weeks 

 they somehow manage to form themselves into distinct, stable winter 

 flocks with mutually exclusive foraging territories." 



Juncos in winter become birds with a definite routine. Each 

 becomes a member of a flock, defined as an association of a group of 

 juncos. The structure of the flock is formed with the earliest arrivals 

 and with the use and occupancy of the foraging areas. Mrs. Sabine 

 says this became obvious to the observer as soon as the first migrants 

 were marked. New arrivals to the flock are integrated into the ex- 

 isting groups without difficulty. Individual birds of an established 

 flock may visit or become temporarily attached to another established 

 flock and are tolerated. Whether birds ah'eady estabhshed in the 

 flock are dominant over new arrivals was not learned. 



Voice. — R. T. Peterson (1961) says, concisely: "Song, a loose 

 musical trill on the same pitch. Note, a fight smack; twittering 

 note." 



To my ear, the usual note between birds of a flock or between the 



