170 PACIFIC COAST AVIFAUNA No. 11 
Status—Common summer visitant in the vicinity of streams through Upper 
Sonoran and Transition the whole length of the state west of the desert divide. 
Southernmost station of actual nesting: Poway, San Diego County (Belding, 
Proce. Calif. Acad. Sci., 2nd ser., 1, 1889, p. 57); abundant in the lowlands of 
the San Diegan district and west-central California, less common in the north- 
west coast belt and in the lower canyons of the western slopes of the Sierras, as 
in Yosemite Valley (several records). Widely distributed during spring migra- 
tion both east and west of the divides, even to the various islands. 
532 (758a) Hylocichla ustulata swainsoni (Tschudi) 
OLIVE-BACKED THRUSH 
Synonyms—Turdus ustulatus swainsoni, part; Olive Thrush, part. 
Status—Fairly common summer visitant to the vicinity of the Warner 
Mountains, in Modoc County: Sugar Hill, Parker Creek, and Dry Creek (Mus. 
Vert. Zool.). Casual, July 22, at head of Grizzly Creek, Trinity County (no. 
19447, Mus. Vert. Zool.). Transient, May 18, Panamint Mountains, Inyo Coun- 
ty (A. K. Fisher, N. Amer. Fauna no. 7, 1893, p. 145). 
533 (759) Hylocichla guttata guttata (Pallas) 
ALASKA Hermit THRUSH 
Synonyms—Turdus minor; Turdus nanus, part; Turdus pallasi var. nanus; 
Turdus guttatus; Turdus aonalaschkae, part; Turdus aonalaschkae auduboni, 
part; Hylocichla aonalaschkae, part; Audubon Hermit Thrush, part. 
Status—Common winter visitant throughout the state below the level of 
heavy snows, particularly in the interior valleys and in the San Diegan district. 
Has been taken east to the Colorado River (J. Grinnell, Univ. Calif. Publ. Zool., 
xu, 1914, p. 215), and to Independence, Inyo County (Mus. Vert. Zool.). 
534 (759e) Hylocichla guttata nanus (Audubon) 
Dwarr Hermit THRUSH 
Synonyms—Turdus nanus, part; Turdus pallasi; Hylocichla aonalaschkae, 
part; Turdus aonalaschkae, part; Hylocichla aonalaschkae verecunda; Dwarf 
Thrush. 
Status—Common winter visitant south throughout the humid coast belt of 
central California; abundant in midwinter in the San Fancisco Bay region; 
occurs sparingly south to Los Angeles County (Daggett, Condor, m, 1901, p. 
131), Palm Springs (J. Grinnell, Condor, vr, 1904, p. 45), and San Clemente 
Island (Linton, Condor, x, 1908, p. 86). 
H. g. guttata and H. g. nanus are, even typically, very much alike, and the 
differences become clearly apparent only upon comparison of series from the 
metropolis of each breeding area. Many winter birds from central and southern 
California have proven impossible to locate with precision under one or the 
other category. 
