Hi -- Well, even though the CCLO hasn't been seen for a while, here is a
bit more info from the Burke Museum. I went up there today (actually I'm
typing this from there) and got quite carried away with hypotheses of
evolution of molt & color in longspurs. But anyway, the Burke has just 5
CCLOs, 3 males and 2 females. The 3 males are all dramatically colored
breeding birds, so they're no help. One female is a summer bird (17 July)
and she indeed has a very dark breast & belly. The color isn't pure black
(as it is on the males), more like dark chocolate brown, but it'd probably
look black in the field. But the other female is a WINTER bird (12 Nov)
and she is completely pale all over -- no dark patch at all on her breast,
just some faint brown streaking on a pale buffy background. Each
individual breast & belly feather has a very long buffy tip, with about a
full centimeter of buffiness to wear away before the chocolate brown base
would show through.

So our Montlake Fill CCLO had a far darker belly than does the Burke's
only winter female, and thus I vote for male. I wish I had more winter
specimens to look at, though -- a sample size of one doesn't really fill
me with confidence!

Interestingly, 3 of the 4 longspur species have a black breast patch that
develops by wear of pale-tipped feathers, & all 4 have a black crown
that develops the same way. The Lapland then supplements this with a
spring molt of black chin & cheek feathers. The Smith's is the only one
without the black breast patch (also the only one with no chestnut
anywhere). But I digress.

cheers,
Kathleen