Back in October, a very strange and stiking bird visited our feeders in
Shenandoah County for about a week. Unfortunately, we didn't have a camera on
hand
but were able to get good looks and prepare a good description. My
conclusion was that the bird was probably a hybrid Dark-eyed Junco x
White-throated
Sparrow. I have written it up in the format for submission to the Raven and
plan
to do so soon. If you are interested, though, I've copied that write-up
below. Sorry that it's rather long for such posts,but perhaps it will be
helpful
to others interested in such potential hybrids.
Dave Davis
Arlington, Virginia
During the period 26 through 31 October, 2003, my wife and I observed a bird
showing characters of a possible hybrid of Dark-eyed Junco (Junco hyemalis)
and White-throated Sparrow (Zonotrichia albicolis). The individual was
visiting
feeders at our home in the upper valley of Cedar Creek in Shenandoah County,
Virginia. We observed this bird while feeding on sunflower seeds on the
ground approximately 20 feet from our dining room windows. Viewing conditions
over
this period varied but were often ideal in terms of lighting and wind.
The bird was feeding in association with a small flock of White-throated
Sparrows (high count of 11) and a few Dark-eyed Juncos (high count of 4), but
the
bird seemed to associate more closely with the sparrows. It was somewhat more
timid with regard to feeding in the open (that is, away from the base of a
large mock-orange bush), but often did feed several feet from the cover of the
bush. Its feeding behavior closely resembled that of the sparrows. It was
observed on one occasion in a large brush pile at the edge of the yard.
The only illustration of a hybrid of these two species that was readily
available to me is in Sibley (2000) on page 494, but that illustration bears
little
resemblance to the bird we observed. Our bird had a medium-gray breast and
head of approximately the same shade of gray as an adult female Dark-eyed
Junco, though somewhat darker. The junco-like hood showed a sharp demarcation
with
its clean white belly. The throat was clean white, and the white area had
the same size and shape as the throat patches of the nearby adult
White-throated
Sparrows.
The bird had distinct dark blackish-brown lateral crown stripes and eye-lines
(on the otherwise gray head) of the same thickness and position as those of a
White-throated Sparrow, except that the eye-lines did not extend much beyond
the eyes, ending in a point, in contrast to the sparrows whose eye-lines
extend to the rear edge of the auriculars and flare out at their terminus. The
supralorals were clean white and extended just above the eyes and tapered to a
point. The supercilium, auriculars, and median crown stripe were all of the
same shade of gray as the breast.
The bill was pinkish, but of a different shade than the typical adult
Dark-eyed Junco-perhaps closer to that illustrated for the "Adult East Taiga"
form of
the White-crowned Sparrow (Z. leucophrys) on page 495 of Sibley (2000). The
feet and legs were of similar color.
The nape was brownish-gray and unstreaked. The mantle was rich chestnut or
rufous with distinct blackish-brown stripes. The wings were brown with two
thin white wing-bars and some richer chestnut or rufous coloration in the
primaries and secondaries. The tertials were blackish with pale edges. At
times the
scapulars appeared gray, but this was less clear and may have been affected
by wind ruffling. Overall, the wings and mantle closely resembled those
illustrated for an adult White-throated Sparrow in Sibley.
The rump was brownish-gray-perhaps somewhat grayer than a typical
White-throated Sparrow. The flanks were tan with very diffuse streaking. In
the tail,
the central rectrices were dark gray-brown, almost slate, but the outer
rectrices were clean white and conspicuous in flight. Although I was able to
observe
the bird in flight only briefly over a distance of perhaps a yard, it
appeared that the tail showed somewhat less white than a typical adult
Dark-eyed
Junco. The undertail coverts were white, but perhaps not so clean and bright as
the belly. Although size was difficult to judge, the bird appeared similar to
the White-throated Sparrows.
No call notes specifically attributable to this bird were heard. No camera
was available.
The observation site is a part-time residence, so it is not known precisely
when the bird arrived and departed. It was not present on the previous visit
14-16 October, so it apparently arrived between the 16th and the 26th. It was
not seen on 1 November, nor on 15-18 November when we returned. Between 1 and
15 November the number of White-throated Sparrows at our feeders declined
from a high count of 11 to a high count of 5, while the number of juncos
remained
about the same. Accordingly, it is likely that the bird departed with some
of the sparrows. It is also possible that it fell prey to an immature
Sharp-shinned Hawk (Accipiter striatus) that was active in the area or some
other
predator in this undeveloped area.
Literature Cited
Sibley, David A. 2000 The Sibley Guide to Birds. Alfred A. Knopf, Inc., New
York.
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