Recognised and fully named
Alan F. Poole, Chris Wood, Marshall Iliff, Matthew Silk, Martin Garner
A true enigma amoung the geese, the Grey-bellied Brant scarcely recognised by the birding fraternity at times, has been named. It has been recognised as full taxonomic entity (with one of those 3 part Latin names- a trinomial). As part of launching the new face of Birding Frontiers we have the privilege of partnering for this post with the Cornell Lab of Ornithology. They have given us access to the full Birds of North America Online with that latest info on Grey-bellied Brant. Here then a fresh look at Grey-bellied Brants, a full book chapter download, a potential new ID character and a special deal from Cornell.
apparent Grey-bellied Brant, Branta (bernicla) nigricans, 13th November 2013 North Lagoon, North Bull Island, Co. Dublin. Niall Keogh. This same bird has appeared over several winters. With slightly asymmetrical pattern of white on neck it may even be the same bird first seen by MG in Co. Down in 1998… A potential new feature was noted by Chris and Marshall in the core winter range of Grey-bellied on the Pacific coast) Specifically the white uppertail coverts appearing longer than in Pale- bellied Brent make the black tail almost disappear at rest. Just as on this Irish bird…
BIRDS OF NORTH AMERICA ONLINE/BRANT
Alan F. Poole
The Cornell Lab of Ornithology’s Birds of North America (BNA) team takes pleasure in making available to UK birders a summary of the latest research findings on Brant (Brent Goose). The BNA life history series, now online, began life as a paper publication, much like BWP (Birds of the Western Palearctic). Completed in 2002, BNA moved online over the next few years, facilitating updates to species accounts at a pace that has accelerated over the past 5-7 years. Fortuitously, given renewed interest in the species, Brant has been one of our latest efforts, thanks to contributions by some of North America’s foremost experts on this species. Readers are invited to jump into this life history account at whatever topic interests them the most. Just click >>> HERE<<< . Migration, Systematics, Distribution, Breeding, and Appearance (Molts and Plumages) have been given the most thorough updates, so those might be good places to start.
What a bird!
Besides undertaking some of the most spectacular migrations of any waterfowl on the planet (fueled, improbably, largely on grasses), Brant are inveterate wanderers, with individuals appearing on most continents and even on oceanic islands like Hawaii. In addition, the remoteness of their high arctic breeding grounds cannot fail to impress us, the sweep of circumpolar breeding that takes in parts of Asia and much of the Palearctic and North America. Although the data remain provisional, we see at least 3-4 forms of Brant, with some intermixing on wintering grounds; readers are encouraged to browse the latest findings on taxonomy (in the Systematics section), and on distribution. Finally, it is interesting to see how much remains to be learned about this bird: the status of breeding populations in Asia; factors influencing fluctuations in populations of North American breeders; changing food resources and how this may effect breeding dynamics; and efforts to set hunting limits and the role science can play in that thorny area.
Alan F. Poole, Senior Managing Editor, Birds of North America Online
apparent Grey-bellied Brant, Branta (bernicla) nigricans, 13th November 2013 North Lagoon, North Bull Island, Co. Dublin. Niall Keogh
Brent Geese of 4 kinds…
The new taxonomic arrangement looks like this:
Dark-bellied Brent Branta (bernicla) bernicla
Pale-bellied Brent Branta (bernicla) hrota
Grey-bellied Brant Branta (bernicla) nigricans
Black Brant Branta (bernicla) orientalis
(n.b the type specimen used for Black Brant was a Grey-bellied looker also called Lawrence’s Brant- hence the transfer in use of nigricans from Black to Grey-bellied)
All 4 brent/brant taxa on North Bull island, Dublin bay in winter 2013/2014/ Photos: 1 and 2 – Tom Coney; 3 – Niall T. Keogh; 4 – Edd Kealy. with thanks to bullislandbirds 2013
Peter Scott’s illustration of the 4 brent geese from ‘A coloured key to the Wildfowl of the World’ published in 1957. This illustrates the specimen now considered the type for Grey-bellied Brant ‘nigricans’. The Lawrence’s or Grey-bellied Brent has been depicted a long time! (as astutely commented on by Richard Millington in the latest and sadly last Birding World.)
The following is an extract from the chapter in Frontiers in Birding -2008:
“I suppose insatiable curiosity is quintessential to discovering new things. When Anthony McGeehan first told about a creature called the ‘Grey-bellied Brant’ of the Canadian High Arctic, he was describing something I had never seen or heard of before. No photos or illustrations appeared anywhere. Yet as I began to read and research it seemed that some, including leading biologists and taxonomists believed that such a creature existed. To me it was near mythical and therefore, of course, all the more fascinating. As I did the sums it became quite obvious; with Ireland hosting almost the entire world population of the only other goose pollution occupying the Canadian High Arctic (some 20,000 Pale-bellied Brent), the occasional occurrence of the Grey-bellied Brant in Ireland should be a foregone conclusion. I didn’t have to wait long.
apparent male Grey-bellied Brant, Branta (bernicla) nigricans with Pale-bellied Brent Geese, Tyrella, Co. Down, April 2001. Martin Garner. It’s possible this is the same bird seen right up to winter 2013/14.
One particular morning in April 1998 I decide to make a concerted effort to go and ‘look for’ Grey-bellied Brant. It felt more like serendipity than sagacity. Within literally one minute of arriving at Dundrum Bay and scanning through the first flock of brent I locked eyes onto a candidate bird. It was this bird that returned to be seen in the same area 3 years later. In 1998 the bird produced almost no interest from sceptical observers, but following some championing of the Grey-bellied cause, the 2001 occurrence resulted in an immediate twitch from Britain’s’ hard core top listers. For the first time I also experienced the awesome potential of the video and stills digiscoping revolution. Having successfully twitched the bird Messers Batty, Hackett, Lowe and Webb returned to my house and it was in reviewing the video footage on my television (and not birding in the field!) that the revelation was first confirmed: It was not one bird, but a full-blown family including identifiable female Grey-bellied Brant and five young. You just couldn’t have written the script!
apparent adult female (centre) with 2 juveniles, Grey-bellied Brant Branta (bernicla) nigricans, Tyrella, Co. Down, April 2001. Martin Garner
Range and status
Black Brant Branta orientalis breeds from the Northwest Canadian Arctic to Alaska, and in northeast Siberia westwards to the Taymyr peninsula, and winters on both sides of the North Pacific, southwards to Baja California in the east and the Yellow Sea in the west.
Dark-bellied Brent Goose Branta bernicla breeds in northwest Siberia east of the Taymyr peninsula, and winters either side of the North Sea, from Denmark to France and in southeast England (between Lincolnshire and Devon).
Pale-bellied Brent Goose Branta hrota occur in two different populations in the Canadian Arctic. The Pale-bellied Brent Goose of the Canadian Low Arctic winter on the eastern seaboard of North America. The Pale-bellied Brent Goose that breeds in the Canadian High Arctic from Melville Island eastwards winters mostly in Ireland. Populations also occur in northern Greenland, Spitsbergen and Franz Josef Land, which winter in Denmark (in Jutland) and in northeast England (in Northumberland).
Grey-bellied Brant Branta nigricans breeds on Melville and Prince Patrick Islands (in the Western Canadian High Arctic). The breeding grounds are therefore to the north of Black Brant and to the west of High Arctic population of Pale-bellied Brent). They winter almost exclusively in Puget Sound, western USA (Padilla Bay, Washington, in particular). Grey-bellied Brant is the least abundant of all the brent geese and has been declining; with an estimated 15,000 birds in 1988, but this has now slumped to between 4,000 and 8,000 birds (Hagmeier 2000). Thanks to recent implementation of shooting restrictions in Puget Sound, this decline may have been slowed, but other factors (such as disturbance from increased human recreation, lack of alternative winter feeding grounds and relatively low breeding productivity due to their harsh nesting environment) may still be affecting their numbers…”
***The above is the opening section on the ‘Brent Goose’ chapter in ‘Frontiers in Birding’ (2008). To download the rest of the chapter – just click on the link below.***
What is a Grey-bellied Brant?
The name Grey-bellied Brant has long been applied to the West Canadian High Arctic (WCHA) population of Brent geese, a population which has recently been given the trinomial Branta bernicla nigricans (see above/below/Cornell article). This population has long remained enigmatic, although recently there have been considerable improvements in our understanding of the distribution and ecology of this population (see above/below etc), enabling it to be established as an ecologically distinct population with its own breeding range, migration phenology (timing of staging in the Izembek Lagoon, Alaska differs from Black Brant) and wintering areas (winters further north than Black Brant, in Washington state).
However, the genetics of the population is only now being fully studied. Preliminary data was presented at a conference in France in 2012. Collectively this seemed (to MS at least!) to point towards the Grey-bellied population being a (stable) hybrid cline between Blacks Brants (Branta bernicla orientalis) to the west and East Canadian High Arctic (ECHA) Pale-bellied Brent Geese (Branta bernicla hrota) to the east. This makes it arguably analogous to the situation with Iceland/Kumlien’s/Thayer’s Gulls in a similar part of the world (more to be explained shortly)….
This is reflected in what the birds look like. Many Grey-bellied Brants on their wintering grounds in Washington are very similar to (or even indistinguishable from) Pale-bellied Brents (see below), whilst others are superficially more similar to pale/washed-out Black Brants (for example the current Irish bird) – with this variability presumably linked to where in the breeding range they are from…
…fingers crossed the science gets published soon and explains the situation more fully than I am able to do here. Despite its origins and variable plumage it is clear this population has a unique ecological identity – time to make your own minds up!
Migration in geese
Why are Grey-bellied Brants expected vagrants?
Migration has been very well studied in a whole range of birds and all of this science – as everyone will know – has shown that where and how a bird migrates is influenced by both its genetics and a process of learning. In geese, it is the latter which is more important and migration routes are learned by juveniles from their parents during their first year of life. Scientists call this process cultural inheritance. This is a process that is fundamental to understanding how and why geese end up where they do, and also how particular migration routes and timings develop in the first place.
A paper on migration of Grey-bellied Brant published in 2013 can be downloaded here:
In terms of vagrancy it has the major implication that if a juvenile of one population/subspecies ends up mixing with individuals from a different population early in its life (say by turning up at a wrong moulting site) then it will “inherit” the wrong flyway and end up as a vagrant. This is why vagrant geese often turn up year after year in the same sites – once they have learned the wrong migration route they are stuck so to speak. A remarkable example of this seems to be the Dublin (and Northern Irish) Grey-bellied Brant – its potentially been wintering in Ireland for over a decade!
This also indicates why Grey-bellied Brants are to be expected in Ireland. As the closest (and somewhat overlapping) breeding population to the Pale-bellied Brent Geese wintering in Ireland they are perhaps most likely to wrongly end up on this flyway. However, it also raises a potential problem…. If variation in Grey-bellied Brants is clinal as predicted then the most likely individuals to turn up are likely to be those that are most similar to Pale-bellied Brents.
Check out the underbelly and especially black tail of this Grey-bellied candidate from Dublin, Ireland last winter. The tail is almost made invisible by longer/more extensive white uppertail coverts than Pale-bellied Brent around about.
However, it seems that new ID features are being developed that may help us pick some of these individuals out in the field (with some caveats which I will discuss more fully next time around)….
Sandra Talbot, G. Kevin Sage, Judy Gust, Jolene Rearick, David Ward & Dirk Derksen. Multilocus phylogeography and population structure of High Arctic North American Brant geese. Goose Specialist Group Meeting, Arcachon, January 2013. Oral presentation.
Sean Boyd, David Ward & Kendrew Colhoun. Migration ecology and affiliation patterns of western & eastern high arctic Brant (B.b.hrota). Goose Specialist Group Meeting, Arcachon, January 2013. Oral presentation.
The Cornell Lab Offer:
**Free 30 Day Offer to BF readers**
In addition to being able to visit Birds of North America Online for 30 days as a special introductory offer, we are now also offering savings of 50% on subscription rates for our 1, 2 and 3 year subscription options for readers of the Birding Frontiers blog. Thus you can now subscribe to the Birds of North America Online at the following rates:
1 year: $21 USD
2 years: $37 USD
3 years: $50 USD
Steps to Purchase a Subscription
All BNA Online subscriptions are purchased through the Cornell Lab of Ornithology’s E Store. So should you decide to purchase a subscription, please:
2. Select the desired subscription term by clicking “Add to Cart”
3. You will then be taken to the “Your Cart” page. To take advantage of this special offer for discounted long term subscription rates, simply put the code EUAU in the Promotion Code field at the left of the page.
If you want to subscribe for 30 days, simply leave the Promotion Code field blank.
Click “Proceed to Checkout”
4. Finish purchasing process
5. Two emails will be sent to you: one will be a receipt and the other email will include a Subscription Code and a link to a BNA Online Account Set up Page.
6. When ready to Activate the subscription, click on the url link in the email and establish a User Name & Password.
7. Insert the Subscription Code in the appropriate field page.
apparent Gray-bellied Brant Branta (bernicla) nigricans 24th March 2013 Gravesend Bay, Kings Count, New York. Marshall Iliff…
Initially identified as possible Gray-bellied and revised to this taxon on 18 Nov 2013. This bird was tough to keep track of but was always obvious when seen, as the dusky color on the flanks stood out from the surrounding B. b. hrota and contrasted strongly with the white flank bars. The dark color extended down to the area between the legs. The neck patch was not different from the hrota, and we did not see other characters that might be intermediate between this bird and Black Brant. So we did not consider it an Atlantic x Black Brant. Solid field identification of Gray-bellied Brant is difficult, but this bird stood out from all Atlantic Brant we have seen in the color of the underparts. While studying this taxon in Washington for the upcoming Princeton Guide, we noticed another field mark — long white uppertail coverts, nearly covering the tail tip. Based on a small sample of only a few dozen birds, this appears to be a useful field mark for Gray-bellied, although it needs more testing. In the video this bird appears to show this more than most of the Atlantic Brant around it. This bird was bigger than the average B. b. hrota, but a few Atlantics were bigger.
Watch video of this bird:
Grey-bellied Brant -December 2005 Steve Mlodinow. While slightly browner on the belly, and with tad large white neck patches, some Grey-bellieds such as these are seemingly indistinguishable from Pale-bellied Brent Geese. On the breeding grounds in the Canadian High Arctic Islands, the plumage of birds seems to vary clinally appearing most like Black Brant (orientalis) in on Prince Patrick Island and virtually indistinguishable from High Arctic population of Pale-bellied Brent (hrota) at the easternmost end of Melville Island.