Date of this Version
Wright, “The Junco Called Cassiar,” from Nebraska Bird Review (June 2013) 81(2).
A well-marked male Cassiar Junco is subtly distinctive. In its overall grayness, the bird closely recalls a Slate-colored Junco, but the darkness of the head, breast, and nape approaches that of a male Oregon Junco, creating a more striking contrast between the "hood" and the rest of the upperparts than is visible in any but the very blackest of male Slate-coloreds. More significant than the colors themselves is their distribution: the blackish nape is sharply set off from the grayer or brownish back, and the dark of the breast meets the paler gray of the flank and the white of the upper belly in a well-defined straight line, where the white underparts of a Slate-colored Junco curve up and into the breast (Rising and Beadle 1996). Thus, a male Cassiar Junco, like the Oregon Junco and unlike the Slate-colored, shows an abrupt "corner" where the breast and the flanks meet, and the white of the upper belly is "concave."
The female Cassiar shares the hooded appearance of the male (and of the Oregon Junco), but the flanks are often strongly washed with gray over brown (thus recalling a Slate-colored Junco). Away from the breeding range, however, many are probably not distinguishable from female Oregon Juncos, while many others are likely identical in the field (or in the hand) to especially brownish (probably first-cycle) female Slate-colored Juncos.
As Nebraska birders look more closely, more Cassiar Juncos will be recorded in the state. In late March 2013, my birding group was able to watch a total of seven males and at least one apparent female in three Nebraska counties; as one of my companions observed, we would never have seen them had we not known what we were looking for.