NORTHERN SLATE-COLORED JUNCO 1039 



ently not of great moment to the species' reproduction. Friedmann 

 (1963) states: 



The slate-colored junco is an infrequently reported host; probably it is mo- 

 lested very slightly by the brown-headed cowbird. Eighteen instances have 

 come to my attention. Three races have been recorded as victims: cismonlanus 

 in British Columbia; carolinensis in Virginia and West Virginia; hyemalis in 

 Alberta, Saskatchewan, Ontario, Quebec, Nova Scotia, New York, Pennsyl- 

 vania, and Ohio. * * * Both cismonlanus and hyemalis have been known to 

 rear young cowbirds. 



In the Peace River District of British Columbia, Cowan (1939, p. 59) found 

 that no fewer than four out of five jimco nests which were observed were para- 

 sitized — evidence which suggests that in tliis region the bird is a commoner host 

 than it has been found to be elsewhere. 



Tlie Communicable Disease Center of the Public Health Service at 

 Atlanta, Ga. has reported finding antibodies of the St. Louis strain of 

 encephalitis in the northern slate-colored junco. Allen Mcintosh of 

 the Animal Disease and Parasite Research Division at Beltsville, Md. 

 writes {in litt.) : "There are 61 references to parasites from this host; 

 the following genera of parasites having been reported: Haemoproteus, 

 Leucocytozoon, Plasmodium, Trypanosoma, Eurytrema, Zonorchis, 

 Diplotraema, Taenia, Filaria, Strongyloides, Sjmgamus, Amblyomma, 

 Analges, Analgopsis, Bruelia Degeriella, Docophorus, Haemaphy- 

 salis, Ixodes, Machaerillaemus, Nirmus, Ornithoica, Ornithomyia, 

 Philopterus, Physostomum, Ricinus, and Trombicula. 



Fall and winter. — About the time the first wintry blasts begin to 

 blow across the great coniferous forests of the North, the j uncos start 

 moving southward. E. A. Preble (1908) last noted them along the 

 Mackenzie River 50 miles below Fort Simpson on October 16. Hous- 

 ton and Street (1959) say the fall migration along the Saskatchewan 

 River usually ends in late October, but some years the birds are 

 common until mid-November. At Pimisi Bay, Ontario, Mrs. Law- 

 rence reports in a letter to Mr. Bent that most of the j uncos leave in 

 October, a few late stragglers occasionally remaining into November. 

 E. H. Eaton (1914) ^Tites that in New York State: 



"In the fall, migrants begin to appear from the 11th to the 28th of 

 September, in the southernmost parts of the State sometimes not 

 before the 4th to the 12th of October. Among the members of the 

 sparrow family, this species rivals the Song sparrow. Vesper sparrow, 

 Savannah sparrow and Chipping sparrow for the place of greatest 

 abundance during the spring and fall migration, probably being as 

 abundant as the Song sparrow in most localities * * * /' 



In her studies of the ^vintering flocks of this junco at Ithaca, N.Y., 

 Winifred S. Sabine (1956) found "that although the migrant individ- 

 uals which are to become winter residents arrive u-regularly over a 

 period of several weeks, they somehow manage to form themselves 



646-737 — 68 — pt 2 29 



