eBird leader Marshall Iliff replied, "It is certainly a Cliff Swallow, with
such a dark throat and the grayish hind collar. However, it is *very*
interesting in that it has a dark forehead. This could indicate a hybrid (I
see no other hybrid traits) or an unexpected subspecies, such as the one
from western Mexico/se. Arizona.
or a dark-fronted bird of the nominate group:
https://www.sibleyguides.com/2011/04/dark-fronted-cliff-swallows-in-louisiana-and-mississippi/
He sent the photos to Andrew Core in AZ who replied, "Very interesting.
I've cc'd Laurens Halsey, who actually lives closer to the
*melanogaster *colonies
along the Santa Cruz River in AZ and sees them more often than I do (he's
traveling this week, though).
I'm struck by how small the forehead patch is. Most of the *melanogaster *I've
seen seen to have larger patches, like this one of Laurens' pix:
https://macaulaylibrary.org/asset/54748701
but note I have a photo of one with a smaller patch here:
https://macaulaylibrary.org/asset/28969771
I don't know what difference the patch shape makes, just wanted to point it
out. The question I have is - do we determine subspecies based on patch
color, or patch shape and color? I suppose there is more to it (in-hand
measurements, etc) but I would probably call this KY bird a *melanogaster *if
I saw it in Arizona - but maybe not if I saw it in March.
While the pale-fronted Cliff Swallows are one our earliest migrants and
have been here in Tucson for a few weeks, the dark-fronted birds don't
usually show up until late April/early May. So a March bird would
definitely gives me pause here, but dark-fronted birds evidently show up in
TX by March: https://ebird.org/view/checklist/S53290091
I think the eastern dark-fronted birds belong to *pyrrhonota*. So, long
story short, the forehead shape and date make me think it's probably one of
the TX/LA/MS birds overshooting its destination."
An interesting bird; thanks to Sunil for photographing it! It was a fun
bird to study.
Roseanna Denton
