Hi Jeff and Tim (and all), apologies for the late response to your comments
on the early reports of Bank Swallows in Harney County. Thanks for the
input!
I was with the group that saw these swallows. I did not originally suspect
Tree Swallows when looking at the birds. I always assumed Tree Swallows we
saw would be in adult plumage, and young birds molt into adult plumage
prior to spring migration.
However, as you point out and the Birds of North America corroborates, some
Tree Swallows do retain their juvenile plumage characteristics as late as
April of their second year. I agree with Jeff, and have seen many young
Tree Swallows that could easily have been confused for Bank Swallows
(without something to reference their size). However, I personally have
only seen such birds in the fall. Now I know to look for them in the spring
as well!
Fortunately Peter Kappes was able to take some photos of the mystery
swallows in question. Our group took the weekend to look over the photos,
compare notes and re-assess. From the photos, it appears the birds were
actually Northern Rough-winged Swallows. I was surprised myself! These
birds certainly did not look like Rough-winged swallows when I saw them
in-person. The chins appeared quite white, not at all dingy, and the birds
had what appeared to be breast bands. Admittedly the breast bands were
probably "hazier" than one would expect of a Bank Swallow. Perhaps these
features were a product of the lighting? The photos themselves are also a
little darker than what we observed due to the challenging light.
White chins and breast bands normally rule out Rough-winged swallows for
me. I wonder if these birds had a particularly fresh (or perhaps
particularly worn) plumage, and their features appeared crisper and more
defined than they do slightly later in the season. Just goes to show, even
with 10 pairs of eyes trained on a bird, swallow identification can still
be a challenge.
I am working with the Bird Nerds to update our lists accordingly. I
appreciate everyone's thoughts and input on these birds. Still looking
forward to our first Bank Swallows of the year, when they return at a more
seasonally-appropriate time!
Thanks again,
Jenna
