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Monday, January 05, 2009

Green-Morph Pine Siskin

The green-morph of the Pine Siskin showed up at our feeders. Only a small percentage of male Pine Siskins are colored like this.

The green-morph Pine Siskin (top, right), normal Pine Siskin (bottom, right), American Goldfinches (on left.)

Note the big, yellow, greater coverts on the wing and yellow at the base of the primary feathers on the green-morph Pine Siskin at the top.

Here you can see that the undertail coverts of the green-morph Pine Siskin on the right are yellow, not white.

A very rare Pine Siskin has shown up at our bird feeder, one that is considerably more yellow than the other Pine Siskins. A small percentage of male siskins can show an abnormal amount of yellow in their plumage and appear greenish on the back. Scientists examining museum specimens found that only 1% had this coloring. These are called "green morphs" of the Pine Siskin. They have more yellow on wing, side of nape, flank and often undertail coverts and the backs may appear greenish. Not much is known about the green-morph, but it is not considered a subspecies difference.
In Pine Siskins in general, males have more yellow on them than females, but this varies by subspecies. The sexes cannot always be accurately identified in the field.

The Eurasian Siskin, quite a rarity in the U.S., can be confused with the green-morph Pine Siskin, especially the female Eurasian Siskin. You can see a photo of the female Eurasian Siskin Here. The male Eurasian Siskin has a black crown and bib and is not as easily confused. The Eurasian Siskin is an Eurasian species, and is accidental in spring in the outher Aleutians. There are records from northeastern N.A. from ME, MA, NJ, NF, etc. but there are questions as to whether these were wild or escaped birds.

There is a very informative paper on "Eurasian Siskins in North America—distinguishing females from green-morph Pine Siskins," in American Birds, 1989, by Mclaren, I. A., J. Morlan, P. W. Smith, M. Gosselin and S. F. Bailey, which spells out the differences and says,

"The large yellow tail and wing patches that may first draw attention to a green-morph Pine Sickin at the same time eliminates the possibility of female Eurasian Siskin. In contrast, real female Eurasian Siskins are not so brightly marked and could easily be overlooked among Pine Siskins....Yellow undertail coverts, if present, eliminate female Eurasian Siskin.

Since our bird had yellow undertail coverts, that would make it a green-morph Pine Siskin.

You can downolad a PDF of the article by googling this -
Mclaren, I. A., J. Morlan, P. W. Smith, M. Gosselin and S. F. Bailey. 1989. Eurasian Siskins in North America—distinguishing females from green-morph Pine Siskins. Am. Birds 43: 1268–1274, 1381

8 comments:

Mike said...

How remarkable! I've never heard of a green morph Pine Siskin, let alone seen such impressive shots. Thanks for the edification.

Antrimlyons said...

Awesome information and photo's. I've been getting so many pine siskins this year. When they first showed up I was thinking purple finches and then when there was about 50 in the yard I was running for the bird books. Never paid much attention to the more yellowish type but I will now.

Jill McElderry-Maxwell said...

I have had a green morph siskin at my feeders since Christmas Day - it is not as extensively yellow on the underparts as your male, but nonetheless is clearly different from the normal PISI (particularly in the sunlight!) Mine was a little tougher to separate from female EUSI, but the yellow wash to the vent feathers was the clincher.

Photographs of my bird can be seen at http://s38.photobucket.com/albums/e117/jillmcm/Siskins/ (the guest password is redpoll)

Melissa said...

What a wonderful treat at your feeders -- both for you and the visiting siskin! Thank you for sharing the great information and fabulous photos!

Chad said...

What a beautiful Pine Siskin!

mckay olson said...

are they in utah?

mon@rch said...

How amazing and I never knew they had this Morph!

Ryan O'Donnell said...

@McCay:
I live in Utah and had a green-morph Pine Siskin at my feeders yesterday, so yes, they are in Utah as well. Sibley says they are most common in the "southwest."