[Tweeters] possible Barn x Tree Swallow

[Steve Hampton]

Wrapping up this discussion (which largely took place on my FB wall and
another FB site), the consensus is that this is a regular first-year BARN
SWALLOW that probably over-wintered in WA or somewhere north. Many produced
pics of similar birds taken in the past week (though none quite so white as
mine, especially on the throat). Apparently this is a normal look for young
birds in winter in South America.

The Birds of the World account shows pics of paler juveniles, which are of
course regular in late summer. These generally have pale buffy underparts
and pale orange throats. They make no mention of birds this white. However,
they do say:

"In western North America, some [first cycle] birds may complete molt in
June or later [i.e. a year after they're born] on summer grounds after
northbound migration; these may represent birds that overwintered farther
north, in the southern United States or Mexico, a trend that appeared to be
increasing during the latter half of the 1900s and first decades of the
2000s."  I'm guessing my bird has not yet begun body molt, which is usually
over by now but can go into June.

I must admit, I'm stunned. In Calif my spring experience with Barn Swallows
was probably older orange adults on territory (e.g. the birds in my
neighborhood). Somehow I'd never seen a bird like this.

thanks all,





On Mon, Mar 21, 2022 at 6:32 PM Steve Hampton <stevechampton at gmail.com>
wrote:


> Today south of Chimicum, Jefferson County, I photographed an

> unusual swallow.

> Photo at *https://ebird.org/checklist/S105328086

> <https://ebird.org/checklist/S105328086>*.

>

> The upperparts were dark blue, similar to Barn Swallow.

>

> It differed from a typical Barn Swallow in the following ways:

> - all the red/orange parts (forehead, throat, underparts, underwings) were

> rather bright white.

> - the forked tail was on the short side, lacking the longest outer

> rectrices.

>

> Also notable is that it was with Tree and Violet-green Swallows, and

> represents the first Barn Swallow of the season in the county; no other

> Barn Swallows were present.

>

> The white in the throat and forehead rules out Eurasian Barn Swallow, as

> well as the even more similar White-throated Swallow (from southern Africa

> and not that migratory, thus virtually impossible).

>

> Dessi Sieburth suggested Barn x Tree Swallow. I can find no reference of

> such a beast, except for this intriguing post from Newfoundland in 2015,

> which is a fairly similar bird:

> https://retiringwithlisadeleon.blogspot.com/2015/05/possible-hybrid-swallow.html

> .

>

> The Birds of the World account says:

> *Barn Swallow*

> *Hirundo rustica* is known to hybridize with both *Petrochelidon

> pyrrhonota*, the Cliff Swallow, and *P. fulva*, the Cave Swallow, with

> records in western North America from Washington south to California,

> western Nebraska, Arizona and Texas, and in eastern North America from

> Pennsylvania south and west to Oklahoma and Texas. In the Old World, the

> Barn Swallow has hybridized with *Delichon urbicum*, the Common

> House-Martin, and *Cecropis daurica*, the Red-rumped Swallow.

>

> *Tree Swallow*

> A mixed pair *T. bicolor* and *T. thalassina* [Violet-green Swallow]

> nested in Illinois, far east of the latter species' normal geographic

> range, but failed to raise young (Johnson and Moskoff 1995). Another mixed

> pair of these two species has been reported at a natural nest in Wyoming

> (S. Johnson pers. comm.), but it is not clear whether that pair produced

> offspring. Otherwise, the sole hybrid reported is a *T. bicolor* × *Petrochelidon

> pyrrhonota* (the Cliff Swallow) collected in Massachusetts (Chapman 1902).

>

> The only other option would be a Barn Swallow with a pigment deficiency,

> though that doesn't account for the short tail.

>

>

> --

> Steve Hampton

> Port Townsend, WA  (qatáy)

>

>

>


-- 
​Steve Hampton​
Port Townsend, WA  (qatáy)
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