This past weekend, while conducting eBird and Feeder Watch counts at
our property in Shenandoah County, we were visited by a Red Fox
Sparrow with some unusual plumage features. Photos are posted on my
Flickr site at http://www.flickr.com/photos/vanburenbirds. (Apologies
for the photo quality; we are still struggling with a new camera whose
autofocus is easily and continuously thrown off by the wire fences we
have in our feeding area.) This bird, which appeared on the 19th and
was still present on the 20th, appeared generally similar to our
typical Red Fox Sparrows (more on this, below). However, it had one
very distinctive and aberrant feature; that is, a grayish, curving
band across the upper breast. The upper border of the band was black,
forming the lower border of a white "bib" below the expected white
throat and dark malars. The bib had only a few, faint streaks, unlike
the heavy streaks expected for the upper, center breast area for all
races of the species. White lores were prominent, reaching slightly
above the eye on the left side. The sides of the neck showed a
distinct white patch. These latter features alone might not have
attracted much attention but for the gray breast band.
Fox Sparrows visit each year, sometimes overwintering, but often
disappearing after late fall and perhaps reappearing in the early
spring. Our birds are typically not as bright as those illustrated
(especially in Sibley) for the nominate race, iiliaca, and the red
group. The reddish areas of the head, back, wings, and breast streaks
for our typical birds are darker and less orange-red than those
illustrated for the nominate race. The tail is generally brighter
than the other red feathers. Gray areas on the crown and head tend to
be more extensive. The colors of the wing feathers for our unusual
visitor were somewhat more muted even than for our typical birds (one
of which also visited this past weekend). Occasionally, we also get
bright orange-red birds, but they are the exception, accounting for
perhaps on the order of 1 in 10 birds.
We are very interested in any opinions for this aberrant plumage
(preferably online, as this isn't really a "personal" matter, but one
of potential interest to many on the list-serve). Some sort of hybrid
is possible (White-throated Sparrow?), but seems remote given size and
genetic differences. Because some of the gray feathers appear loose
or curled, it is also possible that this is an artifact of molting,
though the upper border of the gray band seems almost too crisp for
that to be the case. Perhaps it's just a one-time fluke.
Birding for the weekend overall was a bit less than thrilling, perhaps
contributing to the fascination with this strange sparrow. Though we
did score a few first-of-season species--phoebe, Tree Swallow, towhee,
and cowbird--both species diversity and numbers were low. Though I
didn't research previous year records, I believe this situation is
rather normal for us in March when some of the winter visitors have
moved on or just dispersed while the migrant breeders and passage
migrants have not yet arrived, with the expected exception of species
like phoebes and early Tree Swallows and towhees.
Good birding to all and Happy Springtime!
Dave Davis
Arlington
