Date: 11/26/18 9:03 pm
From: Jay Withgott <withgott...>
Subject: [obol] Re: Eastern Bluebirds today -- sexes & subspecies

Hi Nels, and all —

My feeling is that both the bluebirds are males. One is perhaps slightly grayer-headed than the other, but neither of them seemed gray enough to be a female, based on my recollection of many Eastern Bluebirds over the years from back East, as well as online photos. I’m certainly willing to be proved wrong, but they both seemed quite blue to me in the field. FWIW, some of my own photos are here: <>.

Fascinating that for a first-ever West-coast record of this species, two individuals would show up rather than one … and then on top of that, interesting that they’d be of the same sex.

I’m more agnostic on whether they look to be the eastern subspecies (S. s. sialis) or the southwestern subspecies (S. s. fulva) of Eastern Bluebird. The eastern one is by far what we’d expect based on geography, migratory tendency, and sheer abundance, but I don’t feel we should simply assume it. Some photos, like Nels’s, appear to show non-orange mottled-looking chins, which would point toward the eastern subspecies. But truth be told, the dark lighting and the spitting rain this morning made for poor conditions for photography, so nailing down the subspecies may be easier if folks can get crisper shots in nice sunlight in future days if the birds stick around.

Jay Withgott

From: Nels Nelson <nelsnelson7@xxxxxxxxx>
To: OBOL <OBOL@xxxxxxxxxxxxx>
Date: Mon, 26 Nov 2018 16:09:58 -0800

Based on my photos, I'm thinking the bird showing the most white on the
throat (and especially my photo showing the dark lateral stripe on the
white throat) indicates the female of the pair. I do believe the other
bird is a male, based on the darker, more extensive rufous on the throat
and sides of neck on the male. This being a life bird for me, I've based
my ID on photos and other field ID info. in Sibley's 2nd Ed. Guide.

Nels Nelson

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