The Two Gambel’s Geese in Oxfordshire
We have had the opportunity over the last few weeks of exploring some of the White-fronted Goose complex. Besides the Greenland and Russian birds at Flamborough, we revisited the Pacific ‘frontalis’– with a bird in Israel. now to finish off, a little surprise f you had not heard of this one before…
The Taiga White-front or Gambel’s Goose
A surprising find at Otmoor RSPB reserve in Oxford by Phil Barnett back in May 2004 eventually identified to a best fit that these 2 first winter birds best fit as vagrants of the North American form gambelli – a ‘Taiga White-fronted Goose’. They look amazing don’t they?
They featured in the ‘Frontiers in Birding’ (the White-fronted Goose chapter by Richard Millington). A more recent paper on the Taxonomy of White-fronted Geese is >>>HERE<<<
Photos by Peter Barker:
Here’s Phil Barnett’s wonderfully fulsome and detailed account from the Oxford Bird Report
The Two Gambel’s Geese in Oxfordshire
Filed Notes (from fuller account in Oxford Bird Report)
They were big birds..not far off Greylag Goose in size. Moreover, they appeared not dissimilar to Taiga Bean Goose in overall structure, with long necks, long, thick orange legs and particularly long bills. The bill colour could change with the lighting conditions, but neither bird showed a pure pink bill or an orange bill; on one bird it was dull pink with a pale grey-buff base, on the other a more obvious orange wash was present over much of the bill. As expected on first-winter birds, the nail was dark grey on both.
Typically for first-winter geese in spring, both birds had undergone a partial body moult which had included at least the head (both were showing a white frontal blaze), and probably the neck, mantle and upper flanks, but no black belly bars had yet appeared. A close look at the head and neck was intriguing. The white frontal blaze was tall (reaching to a blunt point above the front of the eye) and wide (especially across the forehead, above the bill), so that the blaze appeared quite angular. Both birds exhibited a fairly obvious yellow-buff eye-ring. The head and neck pattern looked distinctive. The Otmoor birds were both greyish brown on the face and fore-neck, but with a dark brown crown (the lower edge of which cut through the eye); this dark crown also extended back to the nape and continued down the rear of the neck. Also, the black band behind the white shield formed a very broad vertical line running from the lores down to the chin, where it broadened to a thick dark throat line.
The upperparts were drab sepia-brown, with reasonably obvious pale fringes to the scapulars, but the tertials were not pale-edged. The underparts were paler grey-brown, but the upper and rear flank feathers were much darker. In spring, many first-winter geese still retain their juvenile tail feathers, and the Otmoor birds were no exception. On both individuals the tail was extensively dark brown, with a fairly narrow white tip to all the feathers and with narrow pale fringes to the outermost pair.
Plainly they are not European White-fronted Geese; they are far too large, rangy and long-billed, while the bill colour and tail pattern also eliminates that form. Greenland White-fronted Goose is a little larger and darker overall than European White-front, with a longer, orange bill and a largely dark tail, but that didn’t seem the right answer…
Martin Reid suggested they were Taiga White-fronted Geese, citing the long neck and long legs (“adaptations to living in taiga habitat that is taller grass, plus shrubs to look over for predators”) and that it looked identical to those which he had seen and photographed in Texas.
To contemplate identifying the Otmoor geese as Taiga White-fronted Geese first requires an understanding that there have been said to be two taiga-breeding races, elgasi and gambelli. The first breeds in Alaska and winters in California and the second breeds in NW Canada and winters in the Gulf states of the USA and Mexico. There appears to be no safe way to tell these two apart, but that may be for good reason; they may in fact be closely related, or at least share similar habitats. The commoner Nearctic form, American White-fronted Goose ‘frontalis’, also shares some features exhibited by Greenland White-fronted Goose, so that too needs to be considered. The choice for the Otmoor birds lies between the three: Greenland flavirostris, American frontalis or Taiga White-fronted Goose gambelli.
While Greenland Whitefront was considered… the extreme size, disproportionately long neck and bill, the bill colouration and the long, thick legs are an even better match for the other Nearctic forms. Greenland White-fronted Goose is not the only form of white-front to show an orange bill; it is frequent in all the Nearctic forms (eg Kauffman 1994, R. Millington pers obs), especially in young birds. While the head and neck colouration may provide strong evidence, the tail pattern could be important too. A first-winter Greenland White-fronted Goose in late May should show an all-dark tail, with merely a remnant pale tip. First-winter American and Taiga White-fronted Goose also show a largely dark tail, but not so extensively dark as that of Greenland White-front; of the two, Taiga has by far the darker (R. Millington & I. Lewington, pers comm). The remnant pale fringe shown by the Otmoor birds appears to match the Nearctic forms but, being rather prominent, perhaps most closely resembles that of Taiga White-fronted Goose. In general terms, American White-fronted Goose closely resembles European White-front, except it is bigger and browner, has a rather darker tail, and often shows a large, orange-toned bill. However, the disproportionately long neck of the larger of the two Otmoor birds, along with its very long bill and long, thick legs, suggest it something different again. All these features, like the tail pattern, appear to better fit for Taiga White-fronted Goose. The Otmoor birds showed a rather distinctive head pattern, which is detailed above, and appears to match that shown by Taiga White-fronted Goose (PB pers comm).
The feeding habits of the Otmoor geese were intriguing. They preferred to feed in overgrown, wet habitat, and were seen up-ending like swans in their quest for aquatic vegetation. While American White-fronted Geese are habitual grazers and Greenland birds frequently root in deeper vegetation, this manner of feeding is described as being entirely typical of Taiga White-fronted Goose…