Sunday, March 6, 2011

American Goldfinch plumage

Starting this morning and going well into the afternoon, the American Goldfinches at my feeders were extremely vocal. I would go so far as to call them raucous, an adjective normally reserved for the Blue Jay. I thought they sounded noisy from inside the house, but once I got outside, it was almost deafening. This is no exaggeration! It was similar to being near a pond full of spring peepers turned up to 11, but not quite as high-pitched. I'm not sure what had them going, but their loud vocalizations inspired me to post some pictures that I haven't gotten around to sharing.

I've been watching the goldfinches at my feeders this season with great interest. They are always one of the most dominant species at the feeder in terms of overall numbers, so I guess it shouldn't be too surprising that I've observed some interesting-looking birds as they come in to dine.

We'll start off looking at some "normal" goldfinches. Here we have 4 very piggy finches stuffing themselves on black-oil sunflower seeds. Unlike Titmice or Chickadees, for example, who have to hold seeds between their toes while they peck them open with their beaks, goldfinches are able to work the seeds open right in their mouth. This means they can just sit on the feeders and go from one seed to the next, while the Titmouse or Chickadee has to pick a single seed and then go fly off to find a suitable perch for holding the seed and pecking it open. Go back and get another seed, fly off to suitable perch, peck open - repeat over and over. What I'm getting at with this is that the goldfinches can be very dominating at the feeders because they don't have to give up their seat at the table every time they go for a new seed. Therefore, the tube feeders tend to be full of only goldfinches a lot of the time.

Anyway, back to the plumage. Like I said, these are "normal"-looking birds in their non-breeding plumage. I'm still working on getting males and females differentiated, which is a little tricky during the winter. I'm pretty sure there's at least one male in the photo above(top right), and I'm basing that on the presence of the yellow "shoulder patch." The others I'm not entirely sure about.

I do feel pretty confident that this is a female, though. The girls, unfortunately, are drab year-round. They molt into slightly perkier feathers for breeding season, but not much. Even the black and white in their wings is kind of dingy-looking, another hint at the sex of the bird.

Here's another female. Drab, perhaps, but still pretty darn cute.

In this aerial ballet I think I see all boys. You'll notice the bird at top center has some black markings on his forehead - a definite field marking of a male. Also, I see more yellow "shoulder patches" on the other two.

This bird really caught me off-guard. First, it's definitely a male - bright yellow all over, and look how crisp the black and white coloring is in the wings and tail. Also, there's the full black cap of a male. There is one problem though: this is bordering on breeding plumage, and this photo was taken on December 4th. What the...????? This is a real head-scratcher for me. Why isn't he in more drab non-breeding plumage? Did he not molt completely in the fall? Is his internal clock off? And why is his beak still dark (it would normally be almost orange during breeding season) - why doesn't it match with what his feathers are showing me?

Here's another series of photos of a similar situation, taken on February 13th. Is it the same bird? What are the chances that there's more than one male in almost full-on breeding plumage hanging around? I saw a similar bird at the feeders today (March 6th). I would have to think it's the same bird on all 3 occasions.

Now we start getting into some of the odd plumage variations I have seen this season. I know that American Goldfinches can look quite patchy and odd when they are going through a molt, but I don't have any reason to believe that any of the remaining photos in this post illustrate molting, simply based on the time of year and the isolation of the patterning. The bird above has an odd white patterning on its head, and also has a pink beak (beak should be dark this time of year).

Here's some more strange patterning on the head, but I see a dark beak, so it can't be the same bird as "pink beak" (both photos were taken on the same day).

Here's my final example of funky plumage patterning on the head - the beak is a mix of pink and dark and there's certainly something odd about the coloring on the head.

The first thing that came to mind when I saw these birds were some terms that I have read over the years: leucistic and piebald. I almost hesitate to mention the terms, though, simply because my understanding of them is very poor, and it would seem that there's not much good information about the terms online, either. All I know is that these are terms used to describe genetic abnormalities that affect pigmentation in animals (not limited just to birds). Cornell has a page that tries to explain some of the terms, but I came away from it still quite confused. The correct use of these terms is even a subject of great contention to some (see a vet's take on it here). If there's anyone out there who can explain all of this to me in plain English, I would love to be enlightened!

I bring all of this up to illustrate that all is not so cut and dry in the world of birding (as if you thought it was!), and also to show that there are always interesting and anomalous things to be on the lookout for, even at our backyard feeders.

Luckily, goldfinches are pretty docile birds in the hand, allowing for good looks at their feathers up close, thus leading to a better understanding of their age and gender. But that's a story for another post...


KaHolly said...

Wow, interesting post. I've never seen such different, distinctive markings on any of the goldfinches at my feeders. I'll have to pay closer attention! ~karen

Ginnymo said...

Great post Heather. I learn something all the time from you. I saw one lone little Goldfinch a couple weeks ago. Not sure if it was a male or female. It was that dingy color. I love seeing them in the spring and summer when the males are real bright yellow. Just wish spring would get here. We had 20 inches of fresh snow on the ground this morning!

Judy said...

Very interesting! I don't have a feeder, so only see the goldfinches in passing. As for the odd colourings - one fall I saw a white blackbird in the flocks at the marsh, but he disappeared pretty quickly. But seeing him in the massed flights, made me realize how much easier it would have been for a raptor to cut him out of the flock.

RuthieJ said...

Nice goldfinch photos Heather.
I love watching their little chirpy spats at my feeders too.