Fellow New York Birders, Greater White-fronted Goose is one of those exciting birds that many of us look for amid flocks wintering Canada Geese and they can turn up pretty much anywhere in the state. Indeed, a respectable number have been reported this winter already from sites in western, central and coastal (Long Island and Staten Island) New York. Among the Listserve and eBird reports, I've noticed that some orange-billed birds are being assigned to the Greenland race ( flavirostris) without further comment. The purpose of this note is to caution observers that the perception of an orange rather than pink bill may not be sufficient to fully establish the subspecies. Unfortunately, there aren't firm rules yet and thus there is a great opportunity for the discovery of new distributional and ID knowledge.
David Sibley has articulated this fascinating challenge very nicely on his blog. http://sibleyguides.blogspot.com/2008/11/identification-tips-for-greenland.html http://sibleyguides.blogspot.com/2008/11/more-on-identification-of-greenland.html As David explains, observable differences between the subspecies occurring within North America are not well understood and the topic should be considered something of a work-in-progress. In addition to bill color (which must be assessed very carefully), it's important to evaluate several additional characteristics if one is to make a tentative assignment to the scarce Greenland-nesting subspecies. These include the thickness of the head, neck and bill, the darker tone of gray/brown on the head and neck, and the narrower pale feather edgings on the tertials, wingcoverts and so on. Obviously, these are highly subjective criteria especially if one is faced with a lone or distant bird, but anyone lucky enough to encounter a small flock might do well by compare the birds to each other, not forgetting that males, females and immatures of the same subspecies will most likely vary from each other in color and bulk. Immature birds lack the strong dark bars across the belly and have a smaller (variable) white patch ('white front') at the base of the bill. Even with this checklist of pro-Greenland features, David writes, "*when I browse photos of White-fronts from other areas they show a bewildering range of variation. Identifying Greenland White-fronts will require excellent views and a careful assessment of all the different identifying features, preferably with direct comparison to other White-fronts, and a healthy dose of caution.*" Another ID pioneer, Ken Kaufman, was one of the first to wonder about this problem (see Kaufman, K. 1994. Point/Counterpoint. Greenland White-fronted Geese - Over-Reported? Birding Vol. 26 no. 6, pp 380-382). His commentary was prompted by wide-scale reporting in the mid-80's of 'Greenland' birds in the Mid-Atlantic states and Appalachian region coincident with, but not explained by, an eastward shift of central flyway geese (Snow, Ross's etc). Were these birds really from Greenland? Another point raised by Kaufman and echoed by Sibley in another recent blog posting, is the difficulty in reliability assessing bill color in the field. He speaks of different observers having different perceptions and of the changing effects of the light on the degree of pink or orange. Most of the literature on this topic has focused on the separation of Greenland-origin birds from the two Eurasian subspecies (both predominantly pink-billed, although this many not hold true in the Far-East where orange-billed birds are noted with regularity) and less has been written on the separation from the more pink-billed North American forms. Kaufman suggests that the North American field guides (pre-Sibley) overstate the uniform pinkness of North American birds. Do some of the North American birds show an intermediate color? Do birds from the more central or eastern part of the North American range show more pink than those in the west? By now you must be wondering why the problem can't be solved once and for all by looking at variation in North American Great White-fronts wintering in the west or center of the continent. How many have bills that could be perceived as orange? I don't know the answer (time for a road trip!) but note that Martin Reid, another careful observer of familiar species, working in north-central Texas photographed an distinctly orange-billed bird (see http://www.martinreid.com/Main%20website/gwgo9.html), which he speculates might belong to the poorly known North American subspecies, gambeli that is presumed to winter in the center of the continent. In commenting on a bird I photographed on Eastern Long Island in Dec 2009, Greenland goose biologist Tony Fox of the National Environmental Research Institute in Denmark wrote "*Although bill colour is not a reliable trait on its own, it is clear that this is very orange in colour which is a good start compared with the very much pinker paler colour of North American races. The general body colour is of a darkish chocolate brown, the NA races tends be more greyish buff, and often pale on the neck and head, palest at the base of the bill and the edge of the white frons (face patch), where it is often edged with a very dark band, almost blackish. This bird has typically darker head and neck, with no contrast at the edge of the frons. The extensive black belly bars are also indicative of a Greenland bird..*" Getting back to New York, I think an important question we need to ask ourselves is whether birds originating from eastern Canada rather than Greenland can also be orange-billed? I DO BELIEVE genuine Greenland nesting birds do occur with regularity on Long Island but wonder if this is the whole story and if such birds actually occur further inland. For example, I recall some well-photographed birds from Hamlin near Rochester last winter that looked orange-billed in photos posted on the web. Are these shots still available? Rochester is further west than I would expect for Greenland birds, which in Europe are predominantly coastal - wintering almost exclusively in Ireland and western Scotland. In an 11 Jan post to Cayuga Birds, Dave Nutter describes an orange-billed bird from Union Springs (Cayuga Co.), again a little further west than I would expect but not impossible. I can vouch that the 6-7 birds in East Hampton (Suffolk Co.) this weekend were all bright orange billed, even the four 1st-winter birds but the distance and biting cold precluded careful study of the other features. This area has hosted Greenland banded Canada Geese for many years. So I put it to the readership, are orange bills unusual or typical of Greater White-fronts in western and central NY? As with gulls, a major problem is that we don't know where most of the birds we study on the wintering grounds actually nest, but I think collecting data (observer perceptions and photographs) on the bill colors in different quadrants of our state may help us chip away at the problem. The folks in Massachusetts have begun doing this and are sharing their thoughts on the state listserve. We should do likewise. Their early observations are thought provoking. One useful offshoot of such 'work' would be the discovery of more Greenland Canada Geese (yellow neck collars beginning with letter G) and of course, rarities such as Barnacle and Pink-footed Geese. Lastly, I've seen it said that Greenland White-fronts are probably becoming more common in the northeastern US but I am not sure what this supposition is based on. Certainly the flavirostris population rose in the 1980's and 90s due to hunting bans on the wintering grounds (UK and Ireland) climbing to a maximum of 35,600 in 1999 but since then numbers have declined substantially to only 23,200 in the spring of 2008. This correlates with a decline in breeding success rather than survival. Expansion of [our] Canada Geese into southwest Greenland may be an important contributing factor in the decline and testing the idea is one of the objectives of the current Greenland Canada Goose banding project. My apologies for a long and possibly tedious posting. I'll end the sermon by encouraging NY birders to photograph any Greater White-fronts they find and to post their shots somewhere accessible to all. Notes on bill color perception in the field to accompany the photos would be particularly interesting. Does the camera accurately record what you saw in the field? Reports of unambiguously pink-billed birds from coastal NY and obviously orange-billed birds from elsewhere merit discussion. -- Angus Wilson New York City & The Springs, NY, USA http://birdingtotheend.blogspot.com/ -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://birdingonthe.net/mailinglists/NYSB.html 3) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L Please submit your observations to eBird: http://ebird.org/content/ebird/ --
