Again redpolls

Yes, another post on redpolls. These guys are incredibly photogenic, and indeed I can't get enough of photographing them. You might think there's nothing much else going on at this hawk watch in Whitefish Point... and you'd be right, actually. For the moment, things remain slow. Yesterday we got hammered with snow all day, and today the world was a fresher white. Eagles were the only raptors seen on migration today, but they were all high. Usually Bald is the more numerous eagle around here, but today I saw more Goldens, five in total.

The bird at the top, pensively looking down, is a Hoary Redpoll. Its ghostly pale appearance and the short, stubby bill are better clues for Hoary than for Common. But all these things are so subtle.

The bill shape is more obvious on this side view of the same bird. It appears to be a female or an immature.

Adult male Common Redpolls are quite colorful in breeding plumage. The cherry red breast on this individual is typical for that species. Hoary Redpoll males tend to have a pink wash on the breast, nothing as bright as this.

Kinda more like this... Except this is not a Hoary! Yes, it's pale and yes, it looks like it has that pink wash on the breast, but take a look at the next picture - of the same bird.

Now it's obvious that this is a Common Redpoll, with a longer bill and more streaking on the flanks than Hoary Redpoll would have. The cheek also seems a little too dark for Hoary. Still, the bird looks deceptively pale overall, and that pink color on the breast also is suggestive of Hoary Redpoll. This individual is a pale young male Common Redpoll, whose reddish color on the breast is just coming on. It's a result of normal feather wear: as the white edges wear off, the more reddish part of the breast feathers become exposed.

This last bird illustrates very well the necessity for combining several field marks when trying to separate the two redpoll species. Not all pale redpolls are Hoaries!

More on redpoll identification

A few days ago, I posted some Hoary and Common Redpoll pictures here, taken at the feeders behind The Owl's Roost, which is the name of Whitefish Point Bird Observatory's gift shop.

Here are some more photos from the same location, taken today.

The snowy-white bird pictured above is of course a Hoary Redpoll. Note, besides the pale appearance and the short, stubby bill, the fine streaking on the sides and the almost complete lack of streaking on the undertail coverts.

Of course, subtle differences in bill size and shape between Hoary and Common Redpoll are difficult to judge on a single individual. Side by side, however, these differences are quite visible. Note that this is a different individual from the one pictured above. This is an adult male - with a pink wash across the breast - while the top bird may be an adult female or an immature.

Often, a first clue to a bird being a Hoary candidate is the difference in overall color. Note how pale this individual is in comparison to the birds surrounding it. An unstreaked rump and the differences noted above will clinch the identification.

About a year ago, David Sibley posted similar photos on his blog, which can be seen here. Sibley's discussion is a lot more precise and detailed than mine here, and centers on separating various subspecies of Common Redpoll, and how they compare to Hoaries and to each other. He specifically talks about 'Greater' Common Redpolls (Carduelis flammea rostrata), a larger and darker subspecies that breeds on Baffin Island and Greenland, and irregularly winters south to the northeastern US (Sibley) but more commonly in northern Canada (Knox & Lowther 2000).

Today I noticed some size differences between the redpolls in the flock at Whitefish Point. Note for example the obvious size difference between the bird on the left back ridge of the bird bath, and the bird to its left (for us right). This putative 'Greater' Common Redpoll is not only bigger, but also more heavily streaked on the sides.

Here's another photo of a Common Redpoll (center) that appears bigger than the others. This bird, however, is a different individual, because its crown is not as red as the previous bird. It tends more toward orange.

And here's another 'Orange-crowned' Redpoll. This also is a Common Redpoll whose 'poll' isn't red, but orange. According to the Common Redpoll BNA account, the "crown [is] shiny, bright poppy red, sometimes more orange or even gold" (Knox & Lowther 2000). I had never seen it before, but apparently this is not all that rare.

Here is a shot of that bird preening. Also conspicuous on this individual is the relative lack of brown tones in its plumage. Still, several field marks points in the direction of Common Redpoll: fairly heavily streaked undertail coverts and rump; relatively longer bill; relatively slender neck. Observe how the streaking on the flanks is less heavy than on the previous 'orange-crowned' Greater Common Redpoll and that structurally the bird seems much more delicate, less bulky.

References
Knox, Alan G. and Peter E. Lowther. 2000. Common Redpoll (Carduelis flammea), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/543
Sibley, David A. 2008. Sibley Guides Notebook, online only: http://sibleyguides.blogspot.com/search/label/redpolls

Redpoll identification

With a cold NNW wind blowing today and a high of -11°C / 12°F (!), wind chill factors plummeted to unbearable depths. Raptor migration also reached its absolute nadir - zero migrants recorded - so let's turn to something more rewarding: redpoll identification.

The problem is well-known: two species, Common and Hoary Redpoll, which are very similar in appearance. Adult males are distinctive, but great care is needed to separate females and immatures of these two species. Overall, Hoaries are paler, with shorter bills, pale rumps (vs. streaked in Common), less streaking on undertail coverts, fainter flank streaking, frosty streaking on the back with pale rear scapulars, and more white on secondaries and coverts.

The photo at the top shows two Common Redpolls in the upper right, with a pale bird on the left that's a candidate for Hoary.

Here is a larger image of the paler bird. (Clicking on these photos will blow them up even further.) Note how pale overall this bird is, with pale rear scapulars, a pale face, and broad white edges on the greater coverts.

The very top photo I cropped to show this bird with some obvious Common Redpolls for comparison. Below is another crop of the same photo, showing what I think are two more candidates for Hoary Redpoll (lower center). The angle on these birds, however, makes their case a harder one to make.

Compare these two birds with the two lower birds on the outsides, and note how much paler they are.

Here's another pale bird, probably one of the three.

Here is the same photo, a little enlarged, with a Common Redpoll in the top left for comparison.

Note that paleness combined with a round, fluffy appearance is not sufficient for calling a bird a Hoary. This is a rather pale Common Redpoll with a round, thick-necked posture suggesting Hoary. Note the longer bill, however, and the absence of white tips on the lower mantle (scapulars). Also, the head is browner than on the three paler redpolls.