[CT Birds] more on Redpolls

[Greg Hanisek]

For those of you who can't get enough on Redpoll ID, below is some more information posted on a different listserv by Ron Pittaway, a keen student of this group who lives in Ontario.

Greg Hanisek

David Sibley wrote on Monday, "there are lots of aspects (about 
redpolls) that could benefit from open discussion." Here are some 
comments resulting from his post and blog...

1. Taxonomy: Troy (1985) concluded that the southern subspecies 
(race) of Common Redpoll (Carduelis flammea flammea) and southern 
subspecies of Hoary Redpoll (C. hornemanni exilipes) were one 
variable taxon. Later researchers questioned Troy's conclusions. 
Seutin et al. (1989, 1992, 1993) noted that age dimorphism was not 
taken into consideration. Based on biochemical evidence, Marten and 
Johnson (1986) found that southern Common (flammea) and southern 
Hoary (exilipes) "seem to have split 550,000 years ago." Knox (1988) 
found no evidence of hybridization, but suspected that it occurs 
occasionally. The AOU (1998) and Knox and Lowther (2000) in the Birds 
of North America do not follow Troy's conclusions. Lumping redpolls 
has not been discussed for many years.

2. Redpoll Variation: Adults and juveniles have a prebasic molt in 
late summer and early fall. Fresh fall basic plumages are much paler 
than summer birds. Redpolls do not have an alternate plumage. They 
acquire a darker breeding dress by feather wear. A large winter flock 
of southern Common Redpolls (nominate flammea) can have four plumage 
types: adult males, first year males, adult females, first year 
females, plus individual variation. Add southern Hoary Redpolls 
(exilipes) to the mix and the potential plumage types doubles to 
eight. Now add "Greater" Common Redpolls (rostrata) which are 
widespread this winter. "Hornemann's" Hoary Redpoll (nominate 
hornemanni) is also being reported this winter.

3. Redpoll Index: It is misleading to compare the fresher and paler 
redpolls seen in fall/winter with the much darker worn summer birds 
used by Troy (1985). Fall and winter birds are a lot less confusing, 
and the confusing ones are mainly females and first year birds. Many 
difficult birds in photos currently being discussed are not that 
difficult, they are simply not shown properly because of bad angles, 
overexposure, underexposure, and inadequate comparisons. The 
difficulties of identifying redpolls are overstated. Redpolls are no 
more difficult than other groups such as peeps, dowitchers, and 
gulls, but it is often difficult to view and photograph redpolls. 
Most birders in the United States (Lower 48) and extreme southern 
Canada are not familiar with Hoary Redpolls. Some are trying to turn 
slightly lighter Commons into Hoary Redpolls, while others are 
hesitating to identify obvious Hoarys.

4. Hoary Redpoll ID: Adult males are easily identified. Most 
non-adult males also can be identified with practice by a combination 
of characters: much whiter overall coloration, very lightly streaked 
to immaculate undertail coverts, white rump, shorter more obtuse 
bill, etc. The treatment of redpolls in the Sibley Guide (2000) is 
excellent and relevant. Some redpolls are best left unidentified, but 
with experience you will be able to identify more non-adult male 
Hoary Redpolls such as this one in Quebec 
http://www.passionphotonature.net/forum/viewtopic.php?t=7234 See 
three more non-adult male Hoary Redpolls 
http://www.jeaniron.ca/2008/HoaryRedpolls.htm

5. Hoary Redpoll status east of Hudson Bay: Reports that the Hoary 
Redpoll (exilipes) is a rare or absent breeder east of Hudson Bay are 
based on very few surveys in this vast area. However, the habitat 
east of Hudson Bay is smaller than west of Hudson Bay.

Acknowledgements: Michel Gosselin, Jean Iron and Ron Tozer provided 
comments and suggestions.

Literature Cited: I can supply full references.

Ron Pittaway
Minden and Toronto, Ontario