[Tweeters] Cassiar Juncoes

Bill Tweit bill.tweit at gmail.com
Tue Dec 28 17:00:53 PST 2021

As suggested earlier in the thread on this, Cassiar are a poorly known
form. There isn't even solid agreement on their name. For eBird
purposes, observers should report them as Dark-eyed Junco (cismontanus).
There are a couple of references on their occurrence locally, one a note in
eBird Northwest:


and the other an article by Steve Mlodinow in Washington Birds 9: 35-38.

There is still a lot to be learned about this form, or plumage type. I've
observed Cassiar types in south central Alaska, an area of contact between
Oregon type on the coast and Slate-colored types in the interior, and
suspect that many of the Cassiar types we get in winter, particularly on
the westside, originate from this contact zone rather than the zone in the
southern Canadian Rockies. The suggestion that they are a product of
stable contact zones between these two subspecies makes a lot of sense to
me. Regardless, it is enjoyable to sort though junco flocks looking for
both Cassiar and classic Slate-colored.

Bill Tweit
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