"Hornemann's" Hoary and "Greater" Common Redpolls

During the December 19th CBC we tallied a total of only eight Common Redpolls at two different feeders. Since then the redpoll scene has become more interesting. As noted in my last post, the backyard flock has grown and at times Hoary Redpolls appear to outnumber Common Redpolls.

A few days ago an unusual male Hoary Redpoll showed up in the late afternoon. It was much larger than the abundant Common Redpolls and 'exilipes' Hoary Redpolls in the yard - in particular, its large, heavy body made the head seem disproportionately small. This is a key characteristic of Hornemann's Hoary Redpoll, the rarest of the recognizable redpoll subspecies in Ontario.

[click on image to enlarge] 

I took a quick burst of photos through our kitchen window and while viewing them later on the laptop, I noticed a couple of very large, heavily streaked Common Redpolls in a few of the frames - Greater Redpoll (Acanthis flammea rostrata)!

numbers refer to subspecies listed below

Accompanying the Hornemann's Hoary Redpoll and the Greater Common Redpoll was the more common (and smaller) "Southern" Common Redpoll.

In the larger flock in the yard were ten or more "Southern" (exilipes) Hoary Redpolls (see previous post).

Thus, I was fortunate enough to observe the four Ontario redpoll subspecies in the yard that day.

As numbered in the previous images, these recognizeable subspecies are:

1. "Southern" Common Redpoll (Acanthis flammea flammea)
2. "Greater" Common Redpoll (Acanthis flammea rostrata)
3. "Hornemann's" Hoary Redpoll (Acanthis hornemanni hornemanni)
4. "Southern" Hoary Redpoll (Acanthis hornemanni exilipes)

Here are a few more photos from the series. Again note the pallor and large size of the "Hornemann's" Hoary Redpoll in the centre. Also, note the similarly large size and dark streaking of the "Greater" Common Redpoll in the rear.

[click on images to enlarge] 

I sent the photos off to noted winter finch prognosticator Ron Pittaway.  He and Michel Gosselin (Canadian Museum of Nature) confirmed the ID's. In print and in on-line publications, these two ornithologists have done much to advance our understanding of redpoll taxonomy and diversity in Canada. David Sibley has also made some great contributions to the subject. Please check the related resources (below) for a wealth of (mostly) on-line materiel.

Ron offered the following comment which may help to lessen confusion when we discuss redpoll subspecies:

Hornemann’s Redpoll and Greater Redpoll are the English common names used by the AOU when subspecies had official common names and I encourage their use today with the interest in recognizable forms. You may here some birders calling both subspecies as Greenland Redpolls, which is confusing and misleading. Both Hornemann’s and Greater Redpolls breed in Canada and the birds we get are mostly from the Canadian Arctic.

A final note on Hoary Redpolls currently in the Marathon area.

Yesterday (January 9, 2011) I walked through some of the scrubby bush beside the mill in Marathon and I came upon a flock of about 20 redpolls feeding on Green Alder seeds.

The birds were very focussed on their foraging and this allowed me the chance to observe most of them at close range - all of the 13 I could see were unambigously pale "Southern" (exilipes) Hoary Redpolls.

More photos of redpolls (including several more of the "Hornemann's" Hoary Redpoll) from our yard in January of 2011.

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Postscript: The story of the invasion by diverse redpolls into northern Ontario during the winter of 2010-2011 - in the format of a 'photo salon' - was featured in the winter issue of North American Birds. The article is available here (pdf).

It provides a thorough review of the finer points, and limitations, of redpoll identification.

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Acknowledgements

Many thanks to Ron Pittaway and Michel Gosselin for commenting on the redpoll identities in the above photos. I'm also grateful to Pete Read and Nick Escott for pointing out that one of the numbered birds in an earlier graphic was likely a CORE, not a HORE. This has been corrected.

Related resources

From Ron Pittaway

• 1992. Recognizeable Forms: Redpolls. Ontario Birds 10 (3):108-114 [pdf].
• Redpoll Challenge: four subspecies [an excellent summary and description of the four recognizeable subspecies found in Ontario].
• Photos of Hornemann's Hoary and Greater Common Redpoll.

From David Sibley

• A summary of redpoll subspecies.
• Redpoll identification.
• Photos of Greater Redpolls.
• Redpoll investigation widens to include "Greater".
• Urging caution when identifying Common Redpoll.  

Peer reviewed

• Knox, Alan G. and Peter E. Lowther. 2000. Hoary Redpoll (Carduelis hornemanni), 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/544 doi:10.2173/bna.544,
• Troy, D.M. 1985. A phenetic analysis of the redpolls Carduelis flammea flammea and. C. hornemanni exilipes. Auk 102: 82-96 [pdf].
• Wetherbee, O.P. 1937. A study of wintering Hoary, Common, and Greater Redpolls, and various intermediates or hybrids. Bird-Banding 8(1): 1-10 [pdf].

Other

• Brinkley, E.S., Buckley, P.A., Bevier, L.R. and A.M. Byrne. 2011. Photo Essay: Redpolls from Nunavut and Greenland visit Ontario. North American Birds 65(2): 2-11 [pdf].
• From Jean Iron, excellent photos of Common Redpolls, Hoary Redpolls and Greater Common Redpolls.
• Excellent in-hand comparisons of Greater and Southern Common Redpolls from Toronto, taken by Seabrook Leckie.
• Great photos of a Hoary Redpoll taken in early January in nearby Hasty Brook, Minnesota. 
• If you're not yet confused and you can't get enough, check Andy Warr's detailed overview of redpoll subspecies (most of which we share) found in the UK.