Mike Tove's Description

Date: Wed, 1 Jan 1997 22:41:11 -0500 (EST)
From: Michael Tove <mtove@intercenter.net>
To: carolinabirds@acpub.duke.edu
Subject: Re: Mystery Bird

I've been working on the possibilities of the Durham mystery bird and here is what I know so far.

1) I do not believe it is a vagrant species from some other part of the world. This means that it is a highly abberrent plumage or other combination of North American species.

2) Owing to the rich colors and the age - at least 2 years old, I believe the bird is an adult male.

3) Size and shape are clearly that of a North American Sparrow, most closely that of a Fox Sparrow.

4) I seriously doubt that bird is a hybrid because NO hybrid combination I can think of could produce the color pattern it shows.

5) Theoretically, it could be a hybrid PLUS an abberrent color form, but the probability of that would be the product of each event separately; i.e. if 1:1,000,000 for hybridization AND also for very abnormal plumage, the combined odds would be 1: 1,000,000,000,000.

6) Except for COLORS, the pattern of a dark solid head grading into coarse chest streaking is typical of the Western form of Fox Sparrow where-as the warm colors are associated with the Eastern form. Western Fox Sparrows have a horn-gray bill; eastern have yellow. The suggestion that the bird is a White-throated does not seem right. First off, it is distinctly bigger than White-throats (I saw both side-by side on the feeder) and the shape is not quite right. The "Towhee-look" that I and others have perceived is largely due to the rather rounded head which seems to be set off from the back a bit by a higher rounded crown than is seen on other sparrows (e.g., White-throat). After examining photos of different sparrow species, I find this feature to be more characteristic of Fox Sparrow than a Zonotricia. Second, I have no way of explaining the coloration and more importantly, the distribution of color on the bird. The bold breast streaking as an extension of a dark hood is a valid field mark and must be considered as resembling the normal color pattern. I have to conclude that the bird is likely a melanomorphic Fox Sparrow from who knows where, but possibly western. The presence of all these plumage patterns in the species is fairly compelling. Melanomorphism is the phenomenon where abnormally abundant melanin production occurs. If we assume that all white becomes brown and any place where melanin is normally present remains relatively unchanged, we get a uniformly dark brown bird. If we then superimpose the pattern of a dark gray head and chest (western form which is the darkest population), we would get black, which is the pattern of the bird in question.

Finally, it occurs to me that starting late February, someone should be LISTENING for the bird. Western Fox Sparrow and Eastern Fox Sparrow have very different songs (may in fact be distinct species). If heard vocalizing, that would tell a lot.

Mike Tove

Date: Sun, 12 Jan 1997 20:48:59 -0500 (EST)
From: Michael Tove mtove@intercenter.net>
To: carolinabirds@acpub.duke.edu
Subject: "Mystery" Sparrow

Dear all,

This is a sort of repeat of an earlier message and is based on my own, rather prolonged view of the bird and not based on any photos or second-hand descriptions. There are certain things that can be stated with certainty and some which cannot. Those which can are as follows:

1) The bird is NOT a towhee. Period. The ONLY thing which "seems" towhee-like is the rounded head; a bit more rounded than that of the White-throated Sparrows which also frequent the feeder.

2) The bird IS a Sparrow, if not 100%, mostly (and I strongly suspect 100%). In size and shape it is most comparable to a Fox Sparrow.

3) The bird is an ADULT. It was seen all last winter.

4) The bird's "odd" plumage is due to abnormal pigmentation (as opposed to being a stray from somewhere else) or to simple hybridization.

5) The bird's plumage is obviously abnormal. the soft parts do not appear to be.

6) The bird has a VERY distinctive pattern of densely packed "spots" on the chest which extend from the black head in a "U" shape to the middle belly area, an unmarked back and scapulars with broad black central shaft streaks (broader than the shaft).

In my opinion, this last observation is the clue to the bird's identity. Forgetting the actual colors (which are melanomorphic (abnormally high concentrations of menalin), the pattern (the distribution) of colors clearly points to a sparrow with a streaked breast, not a clear breast. There are only 3 large adult sparrows with streaked breasts: Fox, Song and Lark Bunting (female). Of those three, ONLY Fox Sparrow has the rufous tones exhibited by this bird. Only Fox Sparrow has the actual breast pattern of this bird and only Fox Sparrow has an unstreaked back (just not the race iliaca). Although I did not think so when I first saw the bird, I believe it is a Fox Sparrow.

Mike Tove