[CT Birds] Fwd: [BIRDWG01] Redpoll Challenge - 4 subspecies

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-----Original Message-----
From: Jean Iron <jeaniron at SYMPATICO.CA>
To: BIRDWG01 at LISTSERV.ARIZONA.EDU
Sent: Tue, 18 Dec 2007 9:36 am
Subject: [BIRDWG01] Redpoll Challenge - 4 subspecies


The Redpoll Challenge: This is a major redpoll winter in southern 
Canada and the United States. The legendary George North of Hamilton, 
Ontario, once saw all four North American redpoll subspecies in the 
same flock on 23 March 1958 near Hamilton (North 1983, Curry 2006). 
Fifty years later this could be the winter to do it again. On 15 
December 2007, Ron and Doug Tozer found a big "snowball" Hornemann's" 
Hoary Redpoll (nominate hornemanni) on the Minden Christmas Bird Count. 
This is the rarest redpoll in southern Canada. On 14 December 2007, I 
saw two "Greater" Common Redpolls (rostrata) at our feeders in Toronto 
and there have been several other recent reports. With these two High 
Arctic subspecies and probably record numbers of "Southern" Hoary 
Redpolls (exilipes) in flocks of "Southern" Common Redpoll (nominate 
flammea), we have all four North American subspecies in southern 
Ontario this winter. Below I summarize the basic information needed to 
understand and identify redpolls with links to photos. 
 
Taxonomy: The American Ornithologists' Union (1998) recognizes two 
species: Common Redpoll (Carduelis flammea) and Hoary Redpoll (C. 
hornemanni). Each has two subspecies (races) breeding in North America. 
Discussion about lumping or splitting redpolls has been off the "radar 
screen" in recent years. The four subspecies are described below. 
 
1. "Southern" Common Redpoll (nominate flammea): This is the commonest 
of the four subspecies in southern Ontario. It is the standard to which 
the other three are compared. In most plumages, it is noticeably 
streaked on the sides, undertail coverts and rump. However, adult males 
in winter have more contrasting whiter rumps (fewer streaks and often 
pinkish) than on worn breeding birds. Adult males are pink-breasted. 
First year males are somewhat darker and often washed with light pink. 
Adult females usually lack pink (sometimes tinged) and first year 
females are the darkest and most heavily streaked of the four age/sex 
classes. 
 
2. "Greater" Common Redpoll (rostrata): This large and dark subspecies 
breeds on Baffin Island and Greenland. Greater Redpolls are a winter 
visitor in small numbers to the southern parts of eastern Canada from 
Ontario to Newfoundland (Godfrey 1986) and to the northeastern United 
States. Greaters are more frequent than Hoarys in some winters 
(Pittaway 1992). The Greater is larger (averages 14.0 cm compared to 
12.5 cm for flammea) and heavier. Other field marks are the Greater's 
thicker bill and somewhat darker and browner coloration with 
conspicuous heavy streaking on the underparts usually extending to the 
undertail coverts. Adult male Greaters have "red of underparts less 
extensive and less intense" than flammea (Godfrey 1986). Males lack red 
on the malar area, which flammea males usually have (Beadle and Rising 
2006). Some observers describe Greaters as House Finch-like. See the 
excellent identification article on Greater Redpoll by Beadle and 
Henshaw (1996) in Birders Journal 5(1):44-47, illustrated by Beadle. 
The differences between the two Common Redpoll subspecies are usually 
obvious when the two are together for comparison (Peterson 1947). 
 
3. "Southern" Hoary Redpoll (exilipes): This subspecies breeds in the 
Low Arctic and much of its range overlaps that of the "Southern" Common 
Redpoll (flammea). It is the much commoner Hoary subspecies, and is 
similar in size to the flammea Common Redpoll. During redpoll flight 
years, it is usually possible to find a few classic adult male exilipes 
Hoarys. Compared to the "Southern" Common Redpoll, they are more 
frosted with white rumps, have lightly streaked flanks and very lightly 
streaked to pure white undertail coverts. Adult females and especially 
first year females can be noticeably streaked. Exilipes Hoary is 
similar in size to flammea Common, but may look slightly larger because 
of its whiter plumage. Hoarys have shorter, more obtuse (stubby) bills 
imparting a distinctive "pushed in face" appearance. Many females are 
identifiable by overall paler coloration and bill shape. Individuals 
appearing intermediate between exilipes and flammea are best left 
unidentified. 
 
4. "Hornemann's" Hoary Redpoll (nominate hornemanni): This is the 
largest, palest and rarest redpoll. Hornemann's breeds in the Canadian 
High Arctic Islands and Greenland and is a great rarity in southern 
Ontario and Quebec. Hornemann's is larger (averages 14.0 cm) than 
"Southern" Hoary (exilipes) which averages 12.5 cm. It is whiter with 
less streaking on the sides and flanks and has immaculate white 
undertail coverts. Adult males have less pink than exilipes, some 
showing only a trace of pink suffusion on the breast. Females and first 
year birds are recognizable if compared directly to the two small 
subspecies, flammea and exilipes, by their larger size. See the 
excellent article on redpoll identification by Czaplak (1995) in 
Birding 27(6):446-457. His photo of Hornemann's on page 448 is 
correctly identified in my opinion. Note larger size of the Hornemann's 
in the photo in American Birds 42(2):239, which is reproduced on Jean's 
website link below. See also Doug Tozer's photo and Ron Tozer's 
detailed description of the recent Ontario "Hornemann's" on Jean Iron's 
website link below. See David Sibley's website link below. 
 
A. Why is there so much plumage variation in redpolls? A flock of one 
subspecies of the Common Redpoll (flammea) will show four plumage 
types: adult males, adult females, first year males and first year 
females. Since there are four redpoll subspecies, a large flock 
potentially could have 16 plumage types, plus considerable individual 
variation. 
 
B. What is the Greenland Redpoll? Historically, the name Greenland has 
NOT been used in North America to describe the rostrata "Greater" 
Common Redpoll (Peterson 1947, Todd 1963, Bent 1968, Terres 1991, 
etc.). However, Greenland Redpoll is the European name for "Greater" 
Common Redpoll (Newton 1972, Jonsson 1993, etc.). Most North American 
publications use Greenland Redpoll for "Hornemann's" Hoary Redpoll 
(Nash 1905, Macoun and Macoun 1909, Taverner 1953, North 1983, etc.). 
The name Greenland causes confusion. Most of our Hornemann's Hoary 
Redpolls and Greater Common Redpolls are coming from Canada, not 
Greenland. To avoid confusion, it is preferable to include the 
subspecies scientific name after the common name, particularly when 
first mentioned: (flammea), (rostrata), (hornemanni) and (exilipes). 
 
TAKE THE REDPOLL CHALLENGE: This is the first winter in decades to 
match George North's Ontario record of four redpoll subspecies in one 
day. Even more amazing, all four were in the same flock. I am not aware 
that North's record has been matched in southern Canada or the northern 
United States. However, Roland C. Clement saw all four subspecies on 12 
March 1944 at Indian House Lake in northern Quebec (Lat 56 15' 0 N, 
Long 64 42' 0 W) south of Ungava Bay close to Labrador. Clement in Todd 
(1963) reported "a feeding flock of mixed migrants that contained ten 
rostrata, thirty flammea, two hornemanni, and about six exilipes." 
 
Three websites with redpoll information and photos. 
Jean Iron <http://www.jeaniron.ca/2007/Redpolls/index.htm> 
Tommy Thompson Park Bird Research Station in Toronto 
<http://www.ttpbrs.ca/> 
David Sibley <http://sibleyguides.blogspot.com/> Scroll down to Tuesday 
December 4. 
 
Acknowledgements: I thank Michel Gosselin of the Canadian Museum of 
Nature for information on redpoll taxonomy and identification. Doug 
Tozer kindly provided his photo of the recent Minden "Hornemann's" 
Redpoll. Jean Iron and Ron Tozer made many helpful suggestions. 
 
Literature Cited: I can supply full references. 
 
Ron Pittaway 
Minden and Toronto ON 
 
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