Friday, December 17, 2010

Unique Juncos

The Dark-eyed Junco is one of the most abundant, variable, and controversial species in North America. The controversy lies in its subspecies, and whether or not they should be considered their own distinct species. It can be very confusing. Suffice it to say, the one we have to be concerned with in Connecticut is slate-colored. The vast majority (99.99%+) of juncos you see here will be of that form. Only rarely has an Oregon form of Dark-eyed Junco been recorded in our state.

The slate-colored form can appear exceptionally variable in itself. You will see very dark gray males to light gray males. Females can be gray with hints of dark brown or with little or no gray and nearly all light brown. Some birds might appear to be pink or nearly black in some spots. A small percentage of slate-colored birds even have a bit of white on the wings (though they are not a part of the white-winged form). Many people (myself included at times) can be fooled into thinking they have a Dark-eyed Junco of a form other than slate-colored only to examine it carefully and figure out it is simply at the extreme end of appearance.

While I was home on Wednesday, I noticed I had at least 75 or so Dark-eyed Juncos around the yard and at my feeders. The night before I stumbled across a couple of old photos (below) that show this interesting Dark-eyed Junco in my yard on December 7, 2008.

Hmm...let's go back to my yard on Wednesday before getting to that guy. I found two fascinating individuals from the large group. The first of these two birds resembles those old photos but has an even more complete, larger, and bolder eye-ring.

The second bird was quite engrossing and more difficult to spot. If one were looking out the window at their feeders, they would never notice it. Even if you were counting each individual of the species, you would very likely not see it. However, I was looking specifically for juncos with pale throats with my 10 power binoculars.

That pale throat is a trait often seen in Dark-eyed Junco and White-throated Sparrow hybrids. You can see a large section of the throat and upper breast are paler than the other gray unlike the typical Dark-eyed Junco. It also has a hint of the dark mustachial marks of a White-throated Sparrow. I talked to junco lover, artist, and expert (only one of his many areas of expertise) Mark Szantyr about these birds and showed him the pictures. He noted both of the features I mentioned in this last bird and added that the inner tertials appear to have white tips that would once again suggest feathers of a zonotrichia sparrow. With all of that in mind, I believe it is probable this individual had at least some White-throated Sparrow in it.

Mark was not quite sure what to make of the first bird with eye-rings. I do think it shows a bit of dark mustachial area for what it's worth. I had no idea what to say about the second eye-ring individual. While examining it I could not pick out anything that was out of the ordinary apart from those eyes. Mark thought it was possible the bird may have a fungal or bacterial growth noting that the rings appear somewhat interrupted and a bit clumpy in areas. This may well be the case, though it did not behave as if it were ill in any way.
We would need the birds in hand to confirm all of these thoughts and hypotheses. After all that I hope it goes without saying that you should stare at your Dark-eyed Juncos!

Photos © Scott Kruitbosch

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