Photo Gallery - 2014 Field Trips
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November 16, 2014 - Resaca de la Palma SP
This female Carpodacus finch showed up at the feeder area; I presumed Purple, but I was advised not to rule out Cassin's. The strong facial contrast certainly suggested Purple, but the more pointed bill, the presence of an eyering, and finer breast streaking that appears to go all the way to the undertail coverts suggest Cassin's. I've included a compilation of comments below, leaving out names on purpose! ☺
In favor of Cassin's:
The primary projection is the give away. Great find!
Does not look like an "Eastern" Purple Finch, but I have no exerience with the western subspecies. Thus by default the bird is probably a Cassin's Finch.
The eyering, pointy bill, streaked undertail coverts, brighter somewhat whitish finely streaked breast, the somewhat ill defined lower section of the malar marks (Purple's are clearly defined on the lower portion better defining the throat), all point to Cassin's Finch which we see pretty often in our neck of the woods.
My understanding is that a broken eye-ring, wider on the underside than on the upper side, is diagnostic for Cassin's. I might be wrong, but my review of specimens and photographs many years ago pointed in this direction. The overall cooleness of the plumage and fineness of streaking, both dorsally and ventrally, are also strongly suggestive of Cassin's. Many years ago I took many measurements on photographs of the two species and calculated some ratios. If I remember correctly, plotting the ratio of culmen length to bill depth versus the ratio of culmen length to loral length (distance from bill to eye) produced two clusters with little overlap (I might be wrong on what the ratios were--it was a while ago). My notes from that exercise are buried deep in some box, and, unfortunately would take a while to find--in any case, it would be better if someone else repeated the exercise (it is important that there be a consistent way of defining landmarks on the bill and face for such measurements; even if I were to do it now, I would be concerned about whether I was using the same methods as a quarter century ago).
The fine sharp streaking on the breast and flanks, straight culmen, and streaking on the undertail coverts all are the spitting image of the Cassin's Finches that are regular in my area (and that I watch intently at my feeder in the hopes that a PUFI will show up in the mix!). The bold face pattern, particularly with the buffy malar area, is not atypical of CAFI (especially first-winter birds) in my experience. I would not think twice about the bird being a CAFI if it was at my feeder.
I agree that this is more likely a Cassin’s. In these the blurred streaking on the breast are visible and I also agree on the bill favoring Cassin’s.
Sure looks like all the female Cassin's that come to my feeder in So Colorado each summer- eye ring distinctive. Though I left the north 30 years ago the facial pattern just does not resemble the female purples I can remember.
[We] looked at these photos and we think it's a Cassin's Finch. The bill shape is very conical, almost perfectly triangular and comes to a sharp point. Plus, the culmen looks pretty much dead straight...all just right for Cassin's. Unless HY purpureus can show narrow, crisp streaking below, Purple Finch would seem to be out of the question. There is certainly no plumage of californicus Purple Finch that matches this. I looked through my images of HY western Purples and the streaks on the underparts of those birds are much broader and blurrier than what this bird shows. I had posted an earlier comment about this bird on ID-Frontiers (based on a single image). That particular photo didn't show the bill shape well, but showed other aspects that I felt suggested Cassin's. [John Doe] had commented earlier saying that streaking on the undertail coverts points away from Purple, but that is not reliable. Young western Purples do have streaking on the undertail coverts. The overall sandy-brown coloration, which generally lacks olive tones, the bill shape, and the crispness and width of the streaking both above and below all fit Cassin's Finch in my opinion.
But I think it could be Cassin's. I like the eye ring, and primary projection, and the extra amount of white below the dark face patch. The streaks could be heavier for a Purple Finch, too. And I am a bit influenced by the reduction in numbers of Purple Finches in my area. I used to get them at my feeders ad have not had one in years, while House Finch is always around. I think Cassin's has remained more reliable in West Texas in winter, and we have just had these extreme cold snaps coming in on winds from the west.
In favor of Purple:
Seems pretty dark and strongly marked; I'd go Purple over Cassin's.
My vote is Purple. We get a lot of Cassin's in New Mexico and the females are a more dainty bird with streaks even finer but more closely spaced than Purple. Also, face is a bit plainer and bill thinner.
Something about the available photos for the Cameron county bird bothered me. Indeed, I ID'd the bird as a Purple Finch in my response to Mary Beth. Yet, most responders suggested that this female bird was a Cassin's Finch. So, I looked at female specimens of these two species in our collections: 4 Cassin's and 14 Purple Finches. Here are the results:
Exposed culmen [measurement of bill length] - CF 13.3-13.6mm, with an outlier of 11.0; PF 11.0-12.1mm, with an outlier of 8.9
I'll let Texbirders draw their own conclusions.
Those erring on the side of caution:
While I generally agree with [John Doe's] take on this bird, streaking on the undertail coverts doesn't necessarily eliminate Purple Finch. Hatch-year Purple Finches, in particular juveniles, often show streaking on the undertail coverts. I looked at my own images of HY Purple Finches (western form) to double check the streaking on the underparts with this bird. Even juvenile Western Purple Finches (ssp. californicus) have broader blurrier streaking on the underparts than this bird. I don't have much familiarity with the HY birds of the nominate ssp. purpureus, which tends to be less olive above and more streaked on the back. I would want to positively eliminate the possibility of a young purpureus before going all in on this being a Cassin's Finch.
Breast streaking though a bit hard to see in the photos seems closer to House but face pattern and bill more like Purple. Wondering if House and Purple hybridize. If so, this could be a hybrid bird.
I'm still not satisfied that this is a "pure" Cassin's Finch. [Sam Smith] even posed the question about hybridization with Purple Finch. I don't have an answer for that, but the strong superciliary patch and the wing length do not support the ID as Cassin's. I do see a weak eye ring and a possible white pattern around the base of the long bill in some images. [Sam] mentioned the culmen shape as another feature favoring Cassin's.
Now for the rest of the morning's pictures...
"Ebony Resaca" from the tram road (in fog)
Presumed Dot-lined Angle Moth
Another foggy resaca
Not sure if this is just another Dot-winged Angle, but it might be...
White-tailed Kite through the haze
Orange-barred Sulphur, one of Resaca's signature butterflies! (Female left, male right)
Worn Mimosa Skipper
Boisduval's Yellow, another specialty (kinda wrinkled on the right...)
A Great Kiskadee thinks about pouncing...
A rare look at the dorsal side of this Silver-banded Hairstreak
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