Archive for November, 2007

Mystery Finch

Wednesday, November 7th, 2007

Just before 3:30 p.m. yesterday, five photos were taken of a very interesting bird. The five photos are below; they were taken by (respectively) spurdin, kitcat, leacox, leacox, and spurdin.

There has been some really interesting discussion in the image comments. There’s also been this cute thing happening where people refrain from voting, giving a “no bird” vote instead, so they can see how other people are voting before committing themselves.

I know from a previous email correspondence with Bryce Lee (the main programmer for the “game” part of the system) that they were very concerned when designing it that people’s votes might be “tainted” by knowledge of how other people were voting. From that perspective, I’m guessing they’d view the “no bird” trick as more of a bug than a feature. But I don’t know; in terms of how we regulars are actually using the system (as distinct from how its designers imagined us using it), it’s a pretty handy technique, and might help us avoid the issue we’ve had from time to time where a pretty solid photo of a new bird ends up parked forever in “disputed” because people can’t change their votes after thinking a bird over for a while.

Of course, there’s no law that says you have to enter any vote at all before you’re ready. True, you’ll miss the chance to get your 1 or 2 points from an early ID, but at this point that doesn’t seem very significant, given how high the cumulative scores have become.

Anyway, let’s get on to the photos of the “mystery finch”:

Image 42117

Image 42120

Image 42123

Image 42124

Image 42125

Here’s a photo of a male House Finch for comparison purposes:

Image 42173

So, what is that guy? Let’s look at some different aspects of the question:

Redpoll? I know robin54 raised the possibility that this might be a Common Redpoll, and image #2, especially, seems pretty Redpoll-ish. But personally, I can’t go there. I don’t know Redpolls from personal experience, but going by Sibley, I’m not seeing the amount of heavy streaking I’d want to see on the flanks, and the facial markings, especially in photo #5 above, seem pretty clearly to exclude that ID. On top of that, it would be a very rare bird well outside its normal range. Yeah; I know birds fly around and rarities happen, but I’d need really, really strong evidence to accept that that’s what we’ve got here. I just don’t see it.

House Finch? At the same time, I really don’t think this is just a fluffed-up House Finch, as some have suggested. Three things lead me to say that:

1) The top of the head is higher, the general body shape is stockier, and the tail is shorter, than I’d expect in a House Finch. Yes, that could be the fluff factor (especially with respect to the head and body), but to me, that bird really looks like a Purple or Cassin’s, rather than a House.

2) There’s what looks like a pinkish wash on the back (see especially image #4).

3) The beak shape (what you can see of it) seems straighter and more pointy than a House Finch (see especially images #1, 2, and 5).

So, that leaves me with a choice between Purple and Cassin’s. And there I’m really torn. Just going on what we can see here, I’d be inclined to say Cassin’s. The length and straightness of the beak, the relatively small amount of color on the back, the brownish back of the head, and the “rosy” red (as distinct from the “wine” red of Purple, or the “brick” red of House) all argue for Cassin’s (at least, judging by the illustrations and comments in Sibley, who I’m relying on pretty heavily here, since I don’t have a lot of personal experience with Cassin’s, or even with Purple, which I confess I tend to ID more by voice than appearance).

But (again, per Sibley) Cassin’s would be out of its range, which Sibley shows as being limited to the mountains. Not very far out of its range, and for all I know a Cassin’s in San Francisco isn’t such a rarity (do we have any Bay Area locals who can chime in on that?) But (again) to ID a bird outside its range (and one that would be new to the game), I’d want to have some pretty strong evidence. Do these images rise to that level?

The images themselves look more like Cassin’s to me. But I think a Purple is more likely to be there, and the two factors pretty much balance each other out.

I think I’m going to have to think about it some more.

I’m interested in any comments anyone else wants to add. And congratulations to spurdin, kitcat, and leacox on getting some great images of a great (if mysterious) bird.

Update: I went ahead and called it a Purple Finch. I just really don’t think it’s a House Finch, but I also really don’t think it’s a clear enough case to call it an out-of-its-range Cassin’s Finch. So I ended up with Purple Finch almost by default, even though (as I acknowledge above) I think it looks more like a Cassin’s than a Purple. Now that I’ve entered an ID, I can see that most of the others who have voted went with House Finch, which I can live with, too. Maybe a really fluffed-up bird fresh out of the birdbath? I guess I’ll never really know.

Later update: The five photos are currently classified as follows, as far as the game is concerned:

  1. House Finch (CF-0, HF-3, PF-1)
  2. Purple Finch (CF-1, HF-1, PF-4)
  3. House Finch (CF-0, HF-3, PF-1)
  4. House Finch (CF-0, HF-3, PF-1)
  5. House Finch (CF-0, HF-2, PF-1)

Another Yellow-rumped Warbler?

Saturday, November 3rd, 2007

Here’s a photo taken at 1:20 p.m. by birdbrain:

Image 41646

I’m pretty sure that’s another shot of the Yellow-rumped Warbler, just like the other ones I spoke about recently. When I entered my ID it was briefly listed as such, which meant the game briefly had 28 species in it. Alas, we’re now back to 27, since a subsequent ID of Orange-crowned Warbler put this image into disputed, just like the other images of this species that we’ve been able to get so far. That’s especially sigh-inducing in that we’ve actually got a couple of images of what I think is an Orange-crowned Warbler (which this bird pretty clearly isn’t), but which are also currently disputed.

Update: Thanks to votes by birdbrain and kryptonkay, we’ve got the ID back. Yay!

Purple Finch!

Friday, November 2nd, 2007

Something really cool about the birdcam is the way people can campaign in the comments for an ID. It’s like the “ask the audience” feature in Who Wants to Be a Millionaire; we get to tap into that whole “wisdom of crowds” thing. It’s not that any given person is necessarily expert in all these subtle points of bird identification, but get enough of us together, and the cases of self-inflicted myopia will (hopefully) cancel each other out, and we end up with the truth. Or at least, a pretty good approximation.

Case in point: the recent campaign by artemis and robin54 to get people to take a second look at some shots that were being reflexively ID’d as House Finch. I read their comments, looked at the pictures, consulted Sibley, and you know what? I think they’re right. So I went ahead and weighed in with a Purple Finch ID on the following image, and between that vote and those of artemis, kitkat, and robin54, it was enough to switch the ID. Yay!

The image itself was taken by vanilla at 9:44 a.m. on November 1:

Image 41357

I also went back and looked through the recent House Finch images, and I think the following is also probably a Purple Finch. This one was taken by vanilla on October 31 at 1:41 p.m.:

Image 41229

The next image was taken by xav at 1:03 p.m. on October 31. I think it looks pretty Purple Finch-y, too:

Image 41220

Finally, in my excitement I entered a Purple Finch ID on the following image, taken by vanilla at 9:28 a.m. on October 29. But in looking at it again, I think the head shape is more House Finch than Purple Finch, and that my ID was a mistake. What do you think?

Image 40863

Anyway, congratulations to vanilla on getting those great shots of what I’m pretty sure actually was a Purple Finch, and to artemis, kitkat, and robin54 for resisting the impulse to go along with the herd. (Heh. I guess they’ve been inspired by the goats, unlike the rest of us sheep.)