Identification of 1st winter birds
Following on from the recent posts about the discovery of Russian White-fronted Geese showing bright orange bills, Martin has asked me to highlight the main features to look for when you think you may be watching a juvenile or 1st winter Greenland White-fronted Goose, bearing in mind that some individuals, especially lone 1st winters seen poorly, distantly or not showing a clear enough set of distinguishing features, may defy full identification. There is still much to learn!
I don’t profess to be an expert on white-fronted Geese; this article is based on my own observations, discussions with others (over many years) and available literature.
So here is a run down of the key identification features:
Colouration is generally deep orange (lacking the obvious dark tip shown by Russian birds); though some can show pink tinges. It is worth noting that during the winter of 2008/09, I observed one adult and one juvenile Greenland White-fronted Goose showing a predominantly pink bill colouration. Taking this into consideration and the recent observations of orange-billed Russian White-fronted Geese in Gloucester, Sussex and in the Netherlands; bill colouration although indicative of identification, cannot be used as a clinching feature.
However bill structure is far more instructive. Compared to the bill of a Russian White-fronted Goose, the bill of a Greenland White-fronted Goose is a large chunky affair (distinctly wedge-shaped). Despite the thicker base to the bill, it is also noticeably longer than its Russian counterpart.
The tail pattern of the Greenland White-fronted Goose is best described as very dark with a very fine white border. Juvenile Russian White-fronted Geese can show an equally fine white border (though generally marginally broader than shown by Greenland White-fronted Goose in my experience); however the dark area of the tail (matching closely the tone of the upperparts) does not seem as dark as that shown by Greenland birds (the dark area of the tail on Greenland birds always looks darker than the tone of the upperparts).
When comparing juvenile Greenland White-fronted Geese with juvenile Russian White-fronted Geese it is perhaps the upperpart plumage tones that are the easiest to see. Greenland White-fronted Geese in juvenile plumage appear very dark brown, an almost concolorous chocolaty brown. Whereas the upperpart plumage of juvenile Russian White-fronted Geese are usually a paler brown-grey in tone. I have however found that plumage tone in Russian birds can be quite variable. The key-difference between the two forms being discussed here in my opinion is the pale fringing on coverts and tertials. This fringing is a relatively indistinct buffish colour on Greenland birds (sometimes barely noticeable on the tertials) and a much more contrasting whitish tone on Russian birds.
Overall size and structure:
As a rule Greenland White-fronted Geese are a larger bird than Russian White-fronted Geese. However this is not always the case; the juvenile Greenland White-fronted Goose that appear in the images of this article appeared noticeably smaller than the accompanying Russian White-fronted Geese.
Structurally there are some distinct differences (though be aware that perception of structure can often change depending on the birds posture; so observations over extended periods of time will be more valuable when assessing structure). Greenland White-fronted Geese are bulky bird (heavy chested) with a comparatively long neck; I would also tentatively suggest that they are more attenuated at the rear. Russian White-fronted Geese are more of a compact goose (well proportioned) with a comparatively short neck.
Features not covered:
How can I talk about White-fronted Geese without mentioning their ‘whitefront’ aka the ‘blaze’. As can be seen by some of the accompanying images, a proportion of juvenile Greenland and Russian White-fronted Geese, which have not commenced their post-juvenile moult in this area simply do not show a white blaze. Thankfully this feature is not a significant factor for identification!
I have not mentioned ‘belly barring’ either as this is another feature that appears only weakly, and that in birds which have begun post-juvenile moult. It is not a key identification feature during the ‘first winter’.
Summary of key features:
|Greenland White-fronted Goose||Russian White-fronted Goose|
|Bill Colour||Orange (generally)-very rarely appearing pinkish||Pink (generally) with dark tip (though rarely orange!)|
|Bill Structure||Wedge-shaped (chunky)/Comparatively long||
Comparatively small and short. Some (males) slightly longer/ larger billed.
|Tail Pattern||Dark (darker than upperparts)/ fine white border||Brown (limited contrast (if any) with upperparts|
|Upperpart Plumage||Dark (chocolaty brown) /subtle buff tones to fringes of coverts and tertials||Brown-grey/ Off-white fringes to coverts and tertials/contrasting|
|Size/Structure||Generally bulky bird (heavy chested) with a comparatively long neck||Compact goose (well proportioned) with a comparatively short neck|
- Nils Van Duivendijk, Advanced Bird ID Handbook The Western Palearctic, New Holland (2011)
- Martin Garner & Friends, Frontiers in Birding, Birdguides (2008)
- Martin Garner pers comm.
- Richar Millington pers comm.
- Derek Charles pers comm.
- Chris Hind pers comm.