Subspecies of Common and Hoary Redpolls

by Ron Pittaway and Jean Iron

Revised January 2015, first published in the journal Ontario Birds 10(3): 108-114, Pittaway 1992.

Introduction

The American Ornithologists' Union Check-list (1998) recognizes two species of redpolls: Common Redpoll Acanthis flammea and Hoary Redpoll A. hornemanni. Each species has two well-marked subspecies in North America. The two subspecies of Common Redpoll are the smaller southern nominate A. f. flammea and the larger northern A. f. rostrata. The two subspecies of Hoary Redpoll are the large northern nominate A. h. hornemanni and the smaller southern A. h. exilipes. Today, experienced observers can identify most redpolls to species and many to subspecies with a high degree of certainty. Take the Redpoll Challenge, which is to see all four subspecies in one day.

Plumages, Molts and Ageing

Adult (definitive basic) redpolls undergo a complete molt of all feathers once a year after the breeding season. Because buffy and grayish feather edges gradually wear off, redpolls in fresh (new) plumage in fall are paler than the same birds in worn (old) summer plumage. In males, the pink coloration is also paler when fresh, gradually becoming richer and redder by spring. Feather wear allows redpolls to don a breeding dress without the need to molt (Newton 1972). This change is shown in the National Geographic Society's Field Guide (Dunn and Alderfer 2011). Compare the illustrations on page 525 of the bright breeding and duller winter plumaged Common Redpolls.

Juveniles lack the red cap and black chin of older birds. On the breeding grounds in late summer, juveniles (not seen in southern Canada) undergo a partial (body) molt to first year (formative) plumage retaining most of the juvenile wing and tail feathers. Male and female first year birds are darker and more streaked than respective adults. First year birds normally cannot be sexed in the field. Redpolls wear their first year plumage for approximately one year, after which they have a complete molt into adult plumage.

Four Redpoll Subspecies

Two Common Redpoll subspecies (left) and two Hoary Redpoll subspecies. Drawing by Michel Gosselin of the Canadian Museum of Nature.

“Southern" Common Redpoll (A. f. flammea)

This Low Arctic subspecies breeds south to northern Ontario (James 1991). It is an irregular winter visitor to southern Canada, sometimes in large numbers. This is the commonest redpoll far outnumbering the other three subspecies and is the standard by which others are compared and recognized. Study the flocks, (bird feeders are ideal), to learn the plumage variations. Adult males are richly coloured with rosy pink. Adult females usually lack any pink coloration. First year males and females are similar with some males tinged with pink. In all ages, the Southern Common Redpoll is streaked on the sides, rump and undertail coverts and the bill is longer and less stubby than in Hoary Redpoll. See six photos below.

Adult male Southern flammea in Toronto on 8 March 2011

Southern flammea In Toronto on 8 March 2011

Southern Common Redpoll (flammea) at Keswick on 5 January 2015. Buffy coloration suggests a first year bird.

Southern Common Redpolls (flammea) eating weed seeds in early winter. Pickering on 7 December 2007.

Adult male Southern flammea in Toronto on 23 January 2013

Probable first year male with a tinge of pink. Toronto on 15 December 2007

"Greater" Common Redpoll (A. f. rostrata)

This large dark subspecies breeds on Baffin Island and in Greenland (Todd 1963). In parallel with the two subspecies of the Hoary Redpoll, there is an apparent gap between the breeding ranges of the two subspecies of Common Redpoll. It is a winter visitor "in small numbers to the southern parts of the East from Ontario to Newfoundland" (Godfrey 1986). The late Richard Poulin (pers. comm.) banded hundreds of redpolls near Ottawa, Ontario, and reported that Greaters were more frequent than Hoaries in some winters. Look for this distinctive subspecies during redpoll irruption years. Greaters are somewhat larger (averaging 14.0 cm) than the "Southern" subspecies which averages 12.5 cm in length (Newton 1972). The difference between the two subspecies is "fairly obvious when the two birds are together in the same flock" (Peterson 1947). Field marks include its larger size and thicker bill, darker and browner coloration than in flammea, and in adult males the red of underparts is less extensive and less intense. Greaters are often described as being House Finch-like.

Greater Common Redpoll (rostrata) in Toronto 8 March 2011. Note extensive black on face and chin.

Three Greater Redpolls (rostrata) in Toronto on 8 March 2011.

Adult male Greater Common Redpoll (rostrata) in Norland on 3 January 2008.

Greater (rostrata) in Toronto on 8 March 2011. More extensive black on face and chin, darker overall, browner, more coarsely streaked, with darker face and a longer tail than in Southern Common flammea.

Greater Redpoll (rostrata) in Toronto on 20 March 2011. More extensive black on face and chin, darker and browner overall, more coarsely streaked, and with a longer tail than in Southern flammea.

Juvenile (back) and probable female Greater (rostrata) in Greenland on 6 September 2013. Streaked juvenile lacks red cap and black chin. Note: redpolls in juvenile plumage of all four subspecies are not seen in southern Canada and contiguous United States.

Greater Redpoll (rostrata) in Greenland on 6 September 2013

Greater Redpoll (rostrata) in Greenland on 6 September 2013

"Southern" Hoary Redpoll (A. h. exilipes)

This subspecies breeds in the Low Arctic and its range overlaps with the "Southern" Common Redpoll. It breeds south to the tundra coast of Hudson Bay in Ontario (Leckie and Pittaway in Cadman et al 2007). During redpoll flight years, it is usually possible to find a few classic adult males. They stand out by their very white frosted appearance, pure white rumps, paler and less extensive pink suffusion on the breast, more lightly streaked flanks, and very lightly streaked to immaculate undertail coverts. Southern Hoaries are similar in size to southern Commons, but usually have shorter, more obtuse (stubby) bills imparting a distinctive "pushed in face" appearance. Some first year and adult female Southern Hoaries can be quite streaked on the rump and sides (Knox 1988). Beware of size illusions that can lead to Southern Hoaries being misidentfied as Hornemann's. White birds often loom bigger than same-sized dark birds and a fluffed exilipes can appear huge. In photos, the distance and angle affect size perception.

Southern Hoary Redpolls (exilipes) are paler overall caused by whiter feather edgings so that Hoaries look like Common Redpolls seen through a white veil (Taverner 1934). Norland, Ontario, on 3 January 2008.

Hoary (exilipes) features are a white rump, white undertail coverts limited to a few streaks and more obtuse bill. Its fluffed appearance could lead to a misidentification of hornemanni. Norland, Ontario, on 3 January 2008.

Southern Hoary Redpoll in Toronto on 29 January 2013.

Southern Hoary Redpoll showing white rump in Toronto on 8 March 2011.

Southern Hoary Redpoll. Buff suffusion on face suggests a first year bird. Norland, Ontario, on 3 January 2008.

Southern Hoary Redpoll with Southern Common Redpoll in background. Note Hoary`s tiny bill. Keswick, Ontario, on 5 January 2015

"Hornemann's" Hoary Redpoll (C. h. hornemanni)

The "Hornemann's" Hoary Redpoll is the largest and palest of the redpolls (Godfrey 1986). There is apparently a gap between the breeding ranges of the two subspecies of the Hoary Redpoll (Todd 1963). Hornemann's breeds in the Canadian High Arctic and Greenland and was until recently considered a great rarity south of the tundra. The AOU Check-list (1957) lists a record from Galt (Cambridge), Ontario. The specimen is in the Royal Ontario Museum in Toronto. The Ontario Bird Records Committee has accepted 10 recent records to date (August 2015) and we know of at least as many that have not been reviewed by the OBRC. For status in Ontario, James (1991) states "During winter very light and larger birds (hornemanni-like) occur in small numbers." Hornemann's is larger (averaging 14.0 cm) than the "Southern" Hoary which averages 12.5 cm in length (Newton 1972). Todd (1963) reports "no overlap in measurements" between the two Hoary subspecies. Compared to the Southern Hoary Redpoll, Hornemann's is known by its larger size, overall whiter appearance, less prominent streaking on the sides, and immaculate undertail coverts; males have less pink which is of a different hue, some showing a mere trace of pink suffusion on the breast (Todd 1963). Michel Gosselin of the Canadian Museum of Nature cautions that the most reliable way to identify Hornemann's Redpoll is by its larger size in direct comparison with other redpolls. See photos below.

Click on photo for larger image. Male Hornemann's Hoary Redpoll is larger compared to Common Redpoll. Roxane Filion took this photo at her feeders in South Porcupine (Cochrane District), Ontario, when the Hornemann's returned on 7 February 2015.

Click on photo for larger image. Male Hornemann's Hoary Redpoll showing larger size compared to two Common Redpolls. Roxane Filion took this photo at her feeders in South Porcupine (Cochrane District), Ontario, on 3 February 2015.

Click on photo for larger image. Adult male Hornemann's Hoary Redpoll (right) in Township of North Frontenac on 28 February 2011. Note larger size compared to a Southern Common Redpoll (flammea). Photo by Amy Kay.

Click on photo for larger image. Hornemann's Hoary Redpoll at our feeders in Toronto on 12 March 2011. Aged and sexed as a probable first year female in formative plumage by the prominent streaking on its sides. Note its heavily feathered leggings. 

Click on photo for larger image. Hornemann's Hoary Redpoll at our bird feeder in Toronto on 23 March 2011. Note larger size compared to Common Redpolls.

Click on photo for larger image. Hornemann's Hoary Redpoll at Marathon, Ontario, on 9 November 2012. Note larger size. Photo by Michael Butler.

Juvenile Hornemann's Hoary Redpoll

Leucistic (partial albino) Redpolls

This may be the first photo ever published of a juvenile Hornemann's Hoary Redpoll. Pond Inlet, North Baffin Island, Nunavut, Canada on 30 August 2015. It was a great thrill to see this most northerly and largest of the redpolls on its breeding grounds. Photo by Ian Scriver.

Leucistic (partial albino) Common Redpolls can occur in any large flock of redpolls, especially during a flight year. They may easily be misidentified as a Hoary. Matt Walter took this photo of a leucistic Common Redpoll at North Bay on 1 April 2013,

Redpoll Variation

A large flock of Southern Common Redpolls (flammea) will show four plumage classes due to age and sex differences: adult males, adult females, first year males, and first year females. Add another subspecies to the flock and now there are eight possible plumage types. Age and sex plus individual variation account for much of the difficulty in distinguishing Common and Hoary Redpolls and their subspecies. Hybridization is apparently rare. Much of the confusion over intermediate birds can be explained by age and sex differences, and individual variation (Knox 1988, Pyle 1997). Individuals showing confusing characters are best left unidentified.

Acknowledgements

We thank Angus Baptiste, Bill Crins, Bob Curry, Bruce Di Labio, Earl Godfrey, Michel Gosselin, Brian Henshaw, Christine Kerrigan, Ian Newton, Henri Ouellet, Mark Peck, Richard Poulin, Ron Tozer, Declan Troy and Mike Turner for much valuable assistance. We are particularly grateful to Michel Gosselin and Declan Troy for their insightful discussions on redpoll identification and taxonomy,

Literature Cited

American Ornithologists' Union. 1957. Check-list of North American Birds, 5th edition. American Ornithologists' Union, Washington, D.C.

American Ornithologists' Union. 1998. Check-list of North American Birds, 7th edition. Allen Press Inc., Kansas.

Cadman, M. D., D. A Sutherland, G. G. Beck, D. Lepage, A. R. Couturier (editors). 2007. Atlas of the Breeding Birds of Ontario published by Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources, Ontario Nature.

Dunn J. L. and J. Alderfer. 2011. Field Guide to the Birds of North America. National Geographic Society, Washington, D.C.

Godfrey, W. E. 1986. The Birds of Canada. Second Edition. National Museum of Canada, Ottawa.

James, R. D. 1991. Annotated Checklist of the Birds of Ontario. Second Edition. Life Sciences Miscellaneous Publications, Royal Ontario Museum, Toronto.

Knox, A. G. 1988. The taxonomy of redpolls. Ardea 76: 1-26.

Newton, I. 1972. Finches. Collins, London.

Peterson, R. T. 1947. A Field Guide to the Birds. Houghton Mifflin Company, Boston.

Pittaway, R. 1992. Recognizable Forms: Redpolls. Ontario Birds 10(3):108-114.

Pyle, P. 1997. Identification Guide to North American Birds. Part 1. Slate Creek Press, Bolinas, California.

Taverner, P. A. 1934. Birds of Canada. National Museum of Canada.

Todd, W. E. C. 1963. Birds of the Labrador Peninsula and Adjacent Areas. Carnegie Museum and University of Toronto Press.