(Originally published in the CT Warbler, January 2008)
A typical exilipes Hoary Redpoll., Coventry, CT, December 2007 (Julian Hough). Small bill, hoar-frosted plumage, prominent white wingbars with diffuse flank streaking are key features. The unmarked white rump is evident in this shot.
Winter is upon us once more and many immigrants are flooding in from food-scarce Arctic areas. Among seed-eating birds sweeping across the state are those dapper little acrobats, the redpolls. This little finch has caused intense debate among birders and taxonomists over how to best classify the different species/subspecies. So, do you know which redpolls you are seeing? Is the pale redpoll in the flock a Hoary Redpoll or just a pale Common Redpoll? Hopefully the following article will simplify the current complexity.
All of the species and subspecies are very similar, so let’s start by setting out the current subspecies of both Redpoll and Hoary Redpoll found in North America:
- Common Redpoll Carduelis flammea flammea (Fenno Scandia, Siberia and N. America).
- “Greenland” Redpoll Carduelis flammea rostrata (Greenland and Baffin Island).
- “Greenland” Hoary Redpoll, Carduelis hornemanni hornemanni (Greenland)
- Hoary Redpoll, Carduelis hornemanni exilipes (N. America and N. Eurasia).
Now that we have set out the current taxonomic forms, let’s take a look at the identification of the redpoll types. To try to avoid confusion, I will refer to them by their colloquial names throughout the following article.
A Connecticut Perspective
When confronted with similar and ‘hard-to-identify’ species pairs, the observer may not be aware of the plumage minutiae that needs to be recorded in writing to document the record. This is especially important in the absence of any photographic evidence. In the case of Hoary Redpoll, since many plumage features overlap to some extent with Common Redpoll, ambiguous descriptions (often made with good intent) of plumage features are often unhelpful and often prove inconclusive. The committee is looking for detailed written description that very specifically details plumage tones and makes direct comparisons with Common Redpoll. It must be apparent in the description that the observer is aware of these subtleties and has tried to specifically record these features so that the committee can put them into context. This may sound rather harsh and daunting, but by following the features outlined below, observers will be aware of the features to key into when writing a field description of any putative Hoary Redpoll.
Common Redpoll (Carduelis flammea flammea)
Common Redpoll., Hadley, Mass, January 2013 (Julian Hough). A paleish bird, but heavily streaked.
The nominate race of Redpoll breeding in North America and Northern Europe. A brownish-gray finch streaked blackish above and across the breast and flanks. The bill is short and yellow, set off by a blackish chin and a red “poll” – a small red area on the fore crown. The wings have two buff-white wing bars and the tail is relatively long and noticeably forked. The rump is variably pale, from grayish-white to whitish, but predominantly overlain with fine brown streaks so that the rump is never totally unmarked whitish as in classic Hoary.
The main confusion is with Hoary Redpoll, especially those Commons with lightly streaked flanks and paler rumps. Care must be exercised when identifying these two species.
Adult Male – winter/summer: Adult males look similar year round, with pink tinges to the face, breast and flanks. Red forehead usually very obvious, contrasting with blackish lures and chins. Face and supercilium usually paler. Underparts dirty white, with lightly streaked flanks and pink flush on breast.
Female/first-winter: Non-adult male plumages in winter are very similar and ageing and sexing are difficult. Any bird lacking pink tinges to the breast is a female or first-winter. Duller overall than male, with fawn wash to face and upper breast and noticeable underpart streaking extending along the flanks. Red fore crown often obscure on many young birds. Very variable, but still darker overall than Hoary Redpoll, with clean whitish upper breast and boldly streaked flanks. The ground color to the upperparts is more brown-gray streaked darker, often with whitish tramlines. The facial area is gray-white, with a whiter supercilium and narrowly streaked darker. Some, presumably young females, show a brown-wash to the ear coverts. The wingbars and tertials edgings are often edged grayish-white.
Hoary Redpoll (Carduelis hornemanni exilipes)
Hoary redpoll (right) with Common Redpolls, Coventry, CT, December 2007 (Julian Hough). In comparison, paler plumage evident as is slightly smaller bill and “small-headed” look. Crown and mantle notably clean and paler than most Commons.
Most vagrants to New England involve the N. Eurasian and North American form, exilipes, which are generally smaller and less strikingly white than the rarer Greenland form hornemanni. This latter form is longer-tailed and bigger-headed than Common or exilipes Hoary Redpoll and is the palest of the forms, a veritable ‘snowball’.
Exilipes is very similar to Common Redpoll. Since plumage characters overlap between Common and Hoary Redpolls, most of the features on plumage tone and prominence of streaking is quite general, even to the point of rendering some birds unidentifiable.
Finding a frosty bird in a flock of Common Redpolls will lead you to consider Hoary. Unfortunately, a bird, which is frostier-looking than other Commons in the same flock, may not necessarily be a Hoary, since male redpolls are paler than females. Inversely, some first-winter female Hoary Redpolls may not be as pale as some Commons!! Now it is easy to understand why Hoary Redpoll is a challenge to identify. Some birds may be quite difficult. I have seen a few birds that have shown quite extensive flank streaking and have rumps that are lightly streaked and have small bills. These may well have been Hoaries, but I felt the need to err on the side of caution. Considering that in any flock you may have a mixture of adult male and females and first-winter males and females it’s no surprise that there is a lot of plumage variation.
Rump pattern: One specific plumage feature which can aid identification in the field is that Hoary Redpolls have a white rump; pure white in males and lightly streaked in females/immatures. While some Commons can show whitish rumps, the ground color is usually grayer overlaid with heavier streaking, especially at the upper and lower end of the rump patch.
Undertail coverts: Common Redpolls show prominent dark streaks on the longest under tail coverts. Many Hoaries have unmarked, pure white undertail coverts. However, some Hoaries can show dark streaks on the longest undertail coverts but they are typically finer than Commons.
Pattern of undertail coverts in ‘classic’ Hoary (left) variation in Hoary showing noticeable streaked longest undertailcoverts (center) and typical Common Redpoll showing broad and noticeable dark feather centers to the majority of feathers. (Julian Hough)
Bill: The bill has a straight culmed and is often smaller than Common and gives Hoary a “pushed-in” look. Combined with the smaller bill, the eye often looks small and adds to the “cute” look. On some Hooray’s the difference in bill size and shape may not be apparent and other features should be taken into consideration.
Size and structure: Hoariest are often appear larger, or bulkier due to their looser feathers. They also look rather bull-necked and are slightly longer-tailed, though the latter feature is hard to determine.
Upperparts: Cold grayish looking, with fine gray-brown streaks and whitish tramlines on the mantle. The paler face and crown often highlight the red cap and blackish lores and chin. Hoaries often are said to show a white “nose band,” which is often brown-buff in pale Common Redpolls (Svensson 1992) though this feature is difficult to evaluate on many published photographs. On presumed female/first-winter, there is often a buffy wash to the face and throat which is often quite well demarcated from the whitish breast.
Underparts: Whitish, especially so in the center of the breast. The brown streaking below is often finer and sparser than most Commons.
Adult Male: Redpolls are at their palest in winter when all the body feathers have fresh tips, so adult Hoaries in autumn are likely to stand out among even the palest Common Redpolls. Male Hoaries have pink (not red) tinges to the breast, but unlike Commons, have a striking unmarked whitish rump and very sparse streaking on the underparts. Upperparts are gray-brown with whitish fringes and show two white wing bars and tertial fringes. The bill is smallish and bright yellow.
Female/first-winter: Lack any pink on the underparts and are variable in plumage, notably in the density of streaking on the flanks and rump. Some (presumably first-winter males) still show a noticeably whitish rump, streaked lightly along the upper border. Other individuals show more heavily streaked rumps and flanks and may be difficult to pick out in a mixed flock. Typically, young birds show a buff wash to the face and upper breast, which is often demarcated from the whitish upper breast.
To summarize, other than bright, white-rumped males, plumage variation makes the identification of first-winter and female Hoary Redpoll difficult and easy to overlook.
The identification of any “pale” redpoll is most likely to be successful if you consider the suite of characters discussed above, namely, proportionately small bill, unmarked, or lightly streaked undertail coverts, sparse streaking on the flanks, relatively uniform white rump and overall whitish wing bars and frost appearance to the upperparts.
While exilipes is the most common form, any noticeably large, long-tailed and bull-headed individual may be the rarer ‘hornemanni’ or Greenland Arctic Redpoll.
Many thanks to excellent local photographers Jim Zipp and Paul Fusco who generously provided images that greatly enhanced this article.