THRUSHES, BLUEBIRDS, AND SOLITAIRES: Family Turdtdae [465] 



Thrushes, Bluebirds, Stonechats, and Soli- 

 taires: FamilyTurdidae 



Northwestern Robin: 



Turdus migratorius caurinus (Grinnell) 



DESCRIPTION. "Head all around black, interrupted by slaty tippings to the feathers 

 posteriorly, so that there is dorsally and laterally a mergence into the color of the 

 back. Eyelids white, except on loral side. Whole dorsal surface uniform dark 

 mouse-gray with a tinge of sepia. Wings and tail blackish, edged with color of back. 

 Outer pair of tail feathers with a terminal bar of white, mostly on inner web, at most 

 3 mm. wide. Proximal to this is an indistinct grayish interval merging into the 

 blackish of the basal portion of the feathers in question. Extreme chin pure white. 

 Throat streaked black on a white ground. Some hazel in malar region. Whole 

 lower surface from behind throat to anal region, including sides and under wing- 

 coverts, clear deep brown of a shade between hazel and chestnut. Anal region 

 abruptly white and crissum mainly white, the fuscous bases showing through, 

 giving a clouded effect." Similar to Turdus migratorius migratorius "but lacks the 

 extended white patch on inner web of outer tail feathers resembles Turdus migra- 

 torius frofinquus in the extremely narrow white tippings of the outer tail feathers, 

 but coloration much darker and size smaller." (Grinnell 1909^) Si%e: Length 

 (skins) 8.15-10.00, wing 4.91-5.35, tail 3.58-4.11, exposed culmen .71-. 79. Nest: 

 A cup of mud and grass, lined more or less with fine grass and rootlets and placed 

 usually in a fork of a tree or on a projecting shelf in a building or on a cliff. Eggs: 

 3 to 5, greenish blue. 



DISTRIBUTION. General: Breeds from Glacier Bay, Alaska, south through the Pacific 

 Coast district to Willamette Valley and northern coast district of Oregon. In Oregon: 

 Permanent resident that breeds in northwestern Oregon and Willamette Valley and 

 at least Clatsop, Tillamook, and Lincoln Counties. Winters throughout State. 



THE BREEDING BIRDS from the Willamette Valley, from Portland to Eugene, 

 although not quite as dark as birds from the Olympic Mountains, Wash- 

 ington, are much closer to caurinus than to propinquus. This is likewise 

 true of the birds of the coast, at least as far south as Lincoln County. 

 When we came to check up on skins we found we had no breeding birds 

 from farther south than Eugene in the western half of the State, so that 

 we are unable to state the exact line that divides the form from propinquus, 

 which breeds in the Rogue River Valley. 



In winter the Northwestern Robin spreads over the State, and every 

 winter specimen we have is caurinus, but we cannot help but believe that 

 more intensive collecting will reveal a fair proportion of propinquus in the 

 winter population. We have numerous winter specimens from western 

 Oregon and winter birds from Mitchell, Klamath Falls, and Wallowa 

 also that are identical with them. Apparently the breeding birds in the 

 eastern part of the State move out and those from farther north and west 

 take their places, though more intensive collecting may reveal that our 

 obtaining only representatives of the race by sporadic winter collecting 

 is only a coincidence. 



