Possible 'Greater' Redpoll? - 22 Feb 2009
As of today I continue to see up to 2 dozen Common Redpolls (Carduelis flammea) and Pine Siskins, along with another dozen or so American Goldfinches. I'm going through 15 lbs. of thistle a week, and today they've emptied the feeders again. But among the numerous redpolls and siskins occupying the feeders I continue to see one, possibly two birds that may be Greater Redpolls (C. f. rostrata).
I first noticed a significantly large redpoll on the 12th of this month, when I came home from work. A single bird was on the feeder and appeared 'large'. With no other birds in the yard I considered it a bit unusual, since all of the finches/siskins/redpolls have travelled as a large flock, and this bird didn't spook when the rest of the flock did. On the 13th I found a large redpoll feeding among smaller redpolls at the feeders outside the kitchen window. The larger bird fed by itself at a feeder while the remaining birds fought over perches on the other feeders. I snapped a number of images of several birds so that I could compare sizes. The image shown left shows a composite of three that have been resized so that the feeders are all the same width (1.5"). The middle bird appears significantly larger and darker than the other two birds on either side. As they fed from the perches the middle bird also took an upright stance, while all other birds have an angled feeding posture. I'm guessing that possibly the larger redpoll has to squat more to reach the 1 3/8" tall feeder hole.
Both David Sibley and Ron Pittaway have written excellent blogs describing the rostrata Greater Redpoll. Generally these birds measure approximately 10% larger and 50% heavier, appear darker with more prominent streaking on the flanks. They have been observed in Michigan but not on a common basis. My bird(s) seem to fit this description. Note the heavy streaking on the sides of the larger, left bird in the first image at top (photographed this morning).
Since I haven't seen redpolls on a regular basis to know whether there is variability in size, I don't know if I'm seeing normal variations in my yard population. So I may not be seeing a real 'Greater' redpoll, but it sure gives me something to look for as I watch these birds empty my feeders.
I would love to hear any thoughts from you redpoll experts!
2506 21st Street, Wyandotte, Wayne, Michigan, US
Feb 22, 2009 12:00 PM - 12:30 PM
Protocol: Stationary
3 species (+1 other taxa)
Common Redpoll (Acanthis flammea) 12
Common Redpoll (rostrata/islandica) (Acanthis flammea rostrata/islandica) 1 As of today I continue to see up to 2 dozen Common Redpolls (Carduelis flammea) and Pine Siskins, along with another dozen or so American Goldfinches. I'm going through 15 lbs. of thistle a week, and today they've emptied the feeders again. But among the numerous redpolls and siskins occupying the feeders I continue to see one, possibly two birds that may be Greater Redpolls (C. f. rostrata).
I first noticed a significantly large redpoll on the 12th of this month, when I came home from work. A single bird was on the feeder and appeared 'large'. With no other birds in the yard I considered it a bit unusual, since all of the finches/siskins/redpolls have travelled as a large flock, and this bird didn't spook when the rest of the flock did. On the 13th I found a large redpoll feeding among smaller redpolls at the feeders outside the kitchen window. The larger bird fed by itself at a feeder while the remaining birds fought over perches on the other feeders. I snapped a number of images of several birds so that I could compare sizes. The image shown left shows a composite of three that have been resized so that the feeders are all the same width (1.5"). The middle bird appears significantly larger and darker than the other two birds on either side. As they fed from the perches the middle bird also took an upright stance, while all other birds have an angled feeding posture. I'm guessing that possibly the larger redpoll has to squat more to reach the 1 3/8" tall feeder hole.
Both David Sibley and Ron Pittaway have written excellent blogs describing the rostrata Greater Redpoll. Generally these birds measure approximately 10% larger and 50% heavier, appear darker with more prominent streaking on the flanks. They have been observed in Michigan but not on a common basis. My bird(s) seem to fit this description. Note the heavy streaking on the sides of the larger, left bird in the first image at top (photographed this morning).
ID was confirmed by Allen Chartier and Ron Pittaway after posting a blog w/ images:
Jerry,
Last winter I helped out a couple times at a banding station in Kalamazoo County where they banded 1700+ redpolls. I handled several birds that were likely "rostrata". There are currently only about a dozen specimens of rostrata from Michigan, and I am planning on writing a short paper on this sometime soon, to be published in Michigan Birds and Natural History.
The rostrata redpolls were indeed larger, weighing between 17-21 grams, while the flammea redpolls weighed between 11-14 grams. For comparison, American Goldfinches weigh 12-14 grams, while American Tree Sparrows weigh 16-22 grams. The upperparts of the rostrata redpolls appeared on average darker than on the flammea redpolls. And, most obvious, the black on the face/throat was noticeably more extensive in the rostrata redpolls. There was also a difference in bill measurements, and a shape difference that was detectable in-hand but may not be in the field. Additional photos of the bill and face of your bird would be helpful.
Allen T. Chartier
amazilia1@comcast.net
Inkster, Michigan, USA
----
Hi Jerry,
This is Ron Pittaway. I looked at your photos. It is a "Greater" Common Redpoll (rostrata). For a second opinion, I sent the photos to Michel Gosselin of the Canadian Museum of Nature. Michel confirmed the identification.
Best wishes,
Ron
Toronto ON
Pine Siskin (Spinus pinus) 12
American Goldfinch (Spinus tristis) 12
View this checklist online at https://ebird.org/checklist/S1
This report was generated automatically by eBird v3 (https://ebird.org/home)
Feb 22, 2009 12:00 PM - 12:30 PM
Protocol: Stationary
3 species (+1 other taxa)
Common Redpoll (Acanthis flammea) 12
Common Redpoll (rostrata/islandica) (Acanthis flammea rostrata/islandica) 1 As of today I continue to see up to 2 dozen Common Redpolls (Carduelis flammea) and Pine Siskins, along with another dozen or so American Goldfinches. I'm going through 15 lbs. of thistle a week, and today they've emptied the feeders again. But among the numerous redpolls and siskins occupying the feeders I continue to see one, possibly two birds that may be Greater Redpolls (C. f. rostrata).
I first noticed a significantly large redpoll on the 12th of this month, when I came home from work. A single bird was on the feeder and appeared 'large'. With no other birds in the yard I considered it a bit unusual, since all of the finches/siskins/redpolls have travelled as a large flock, and this bird didn't spook when the rest of the flock did. On the 13th I found a large redpoll feeding among smaller redpolls at the feeders outside the kitchen window. The larger bird fed by itself at a feeder while the remaining birds fought over perches on the other feeders. I snapped a number of images of several birds so that I could compare sizes. The image shown left shows a composite of three that have been resized so that the feeders are all the same width (1.5"). The middle bird appears significantly larger and darker than the other two birds on either side. As they fed from the perches the middle bird also took an upright stance, while all other birds have an angled feeding posture. I'm guessing that possibly the larger redpoll has to squat more to reach the 1 3/8" tall feeder hole.
Both David Sibley and Ron Pittaway have written excellent blogs describing the rostrata Greater Redpoll. Generally these birds measure approximately 10% larger and 50% heavier, appear darker with more prominent streaking on the flanks. They have been observed in Michigan but not on a common basis. My bird(s) seem to fit this description. Note the heavy streaking on the sides of the larger, left bird in the first image at top (photographed this morning).
ID was confirmed by Allen Chartier and Ron Pittaway after posting a blog w/ images:
Jerry,
Last winter I helped out a couple times at a banding station in Kalamazoo County where they banded 1700+ redpolls. I handled several birds that were likely "rostrata". There are currently only about a dozen specimens of rostrata from Michigan, and I am planning on writing a short paper on this sometime soon, to be published in Michigan Birds and Natural History.
The rostrata redpolls were indeed larger, weighing between 17-21 grams, while the flammea redpolls weighed between 11-14 grams. For comparison, American Goldfinches weigh 12-14 grams, while American Tree Sparrows weigh 16-22 grams. The upperparts of the rostrata redpolls appeared on average darker than on the flammea redpolls. And, most obvious, the black on the face/throat was noticeably more extensive in the rostrata redpolls. There was also a difference in bill measurements, and a shape difference that was detectable in-hand but may not be in the field. Additional photos of the bill and face of your bird would be helpful.
Allen T. Chartier
amazilia1@comcast.net
Inkster, Michigan, USA
----
Hi Jerry,
This is Ron Pittaway. I looked at your photos. It is a "Greater" Common Redpoll (rostrata). For a second opinion, I sent the photos to Michel Gosselin of the Canadian Museum of Nature. Michel confirmed the identification.
Best wishes,
Ron
Toronto ON
Pine Siskin (Spinus pinus) 12
American Goldfinch (Spinus tristis) 12
View this checklist online at https://ebird.org/checklist/S1
This report was generated automatically by eBird v3 (https://ebird.org/home)
