Category Archives: b) Geese

Gambell, Alaska in September 2014

Outstanding outpost for North American Birders

Paul Lehman

Paul’s been writing of rather gripping exploits once again on his favourite autumn patch on Gambell. And if you fancy an ID challenge there’s one of those giant Bean Geese thrown in to the mix. Of course it’s ‘carrier’ species isn’t the same as ours¬†ūüėČ ¬†read on…

“We have all sorts of good photos of stuff this fall¬† both Asian and North American…

Red-flanked Bluetail. 30th September 2014. Gambell, Alaska. Paul Lehman

Red-flanked Bluetail. 30th September 2014. Gambell, Alaska. Paul Lehman

There has also been a slug of good birds farther to the south at the Pribilofs, also with excellent photos, ¬†(things like Siberian Chiffchaff, Red-flanked Bluetail, Gray-streaked Flycatcher, Taiga Flycatcher, Dusky Warbler, Jack Snipe, Garganey, Common Rosefinch, etc.–though not any great North American strays like we have had).

BTW,¬† we’ve had some very good Asian species this year (e.g., 2 Tree Pipits, Yellow-browed and 2 Willow Warblers, 2 Brown Shrikes, Common Rosefinch, Eurasian Hobby, the goose, juvenile Red-necked Stints) and even some better North American waifs–which would obviously make big Eastern Palearctic news if someone ever saw them in Russia:¬† NORTHERN MOCKINGBIRD, Red-eyed Vireo, Mourning Warbler, Least and Alder Flycatchers, Rusty Blackbird, Townsend’s Warbler, etc.

Then on 30th September on the ABA blog:

“News from western Alaska, Paul Lehman and company found a number of noteworthy birds highlighted by an ABA Code 4 Red-flanked Bluetail and also including Rustic Bunting (3) and two Little Buntings (4), at Gambell, on St. Lawrence Island. Read more

 

Bean Goose Identification:

We found a Bean-Goose this afternoon (16th September), below Troutman Lake, flying by
with an Emperor Goose.  See one of my photos, attached. The bird was
HUGE–seemingly 1-1/2 times the size of the Emperor in both body bulk
and wingspan when observed in the field. And the bill shape looks
interesting.

BIG Bean Goose with Emperor Goose. But which taxon  (or even which species?). 16 September 2014. Paul Lehman

BIG Bean Goose with Emperor Goose. But which taxon (or even which species?). 16 September 2014. Paul Lehman

 

juvenile Red-necked Stint late August 2014. Paul Lehman

juvenile Red-necked Stint late August 2014. Paul Lehman

juvenile Red-necked Stint late August 2014. Paul Lehman

juvenile Red-necked Stint late August 2014. Paul Lehman

 

Wood Warbler, 19th September 2014. Paul Lehman

Wood Warbler, 19th September 2014. 

Siberian Accentor, 19th September 2014. Paul Lehman

Siberian Accentor, 19th September 2014. Paul Lehman

 

hybrid Brent Goose?

Spurn 4th May 2014

Enjoyed joining in a special weekend with some 23 ‘NGB birders’ camped out at Spurn in liaison with the Observatory. I spent the morning at the Warren where light but consistent spring migration was very apparent. Hobby, 7 Barnacle Geese, 2 Corn Buntings, a Little Ringed Plover, a couple of Marsh Harriers, plenty flava wagtails¬†and quite a few hirundines all added to the mix.

One of these geese is not like the others. One of these geese doesn't belong...

One of these geese is not like the others. One of these geese doesn’t belong…

Me, I took a long look through the Brent Geese on the Humber shore. As expected most birds were Dark-bellied Brents. One adult Pale-bellied Brent (and later one 1st winter) were there to compare. One bird stood out- a little ūüôā . Basically like a Dark-bellied but with paler looking flanks. Essentially the white in the flanks feathers was broader more cotton wool fluffy. Was this just variation? It felt a bit ‘intermediate’ and I mentioned it to others at ‘Numpties’ watchpoint. I am well aware that with angle and light Dark-bellied Brent flanks can look very variable. This seemed outwith normal Dark-bellied so Lizzie, Nathan and I went for a closer look.

 

Pale-bellied Brent (back), interesting Brent (middle on mound), Dark-bellied Brent at front

Pale-bellied Brent (back), interesting Brent (middle on mound), Dark-bellied Brent at front

I can’t show you in a pic but on the right side there was a line of broadly white -tipped greater coverts which I think is remnant of juvenile plumage- therefore a more advanced 2cy I presume.

interesting Brent

interesting Brent

to compare, normal Dark-bellied Brent

to compare, normal Dark-bellied Brent

On closer inspection the flanks remained outstanding. Furthermore the dark area under he legs was less extensive, a tad paler and more broken up distally looking slightly ‘spotty’ compared with¬†the other Dark-bellieds. The upperparts were nicely brownish towards the neck with nice pale buff fringes ¬†(bit more Pale-bellied like?) but more metallic grey towards the rear. With moult going on in this and other Brent it was hard to make firm comment on the upperparts. Have a look though the pics, to see what I mean. I wonder if it’s a mix of Dark and Pale-bellied Brent. A¬†hybrid?

 

One further question. I saw some obvious 2cy with retained coffee with cream coloured belly and lots white-tipped coverts. Other like this bird had a small row on white-tipped coverts one one side (on right side- not in photos) Is this variation in moult in 2cy normal in spring or am I misinterpreting?

Interesting Brent on left. See dark area on belly

Interesting Brent on left. See dark area on belly

Interesting Brent flanked by 2 Dark-bellied Brent

Interesting Brent flanked by 2 Dark-bellied Brent

hybrid Brent thing n at Spurn 4.5.14

Interesting bird on left

Interesting bird on left

rear view

rear view

what's the answer?!

what’s the answer?!

 

Black Brant and hybrids

in Norfolk – March 2013

by James McCallum  (photos Martin Garner)

March and April are key time for watching and studying the 4 Brents. Spring movement ¬†and flock shuffling. Lots to watch and learn. James McCallum’s study of Black Brant and theory hybrids in Norfolk in full of useful stuff.

 

Black brant hybrid lone bird aAdult Black Brant X Dark-bellied Brent, Holkham, February 2013

Some of my earliest memories of growing up on the north Norfolk coast are of flocks of Brent Geese and their lovely muttering calls. In my early teens I developed a stronger interest in the local bird life and a closer look at the Brent flocks occasionally revealed the presence of a few Pale-bellied Brents and, more rarely, a Black Brant. Such occurrences set the scene for the following two decades ‚Äď although in some winters, small influxes of Pale-bellied Brents occurred and occasionally two or three Black Brants graced the local flocks.

In January 2001 I was watching a flock of Brents at Burnham Deepdale when, suddenly, a rather well-marked Black Brant walked into my telescope view. This well-built bird frequently adopted a very upright stance and regularly made threat postures aimed towards other geese that ventured too close. I was confident that it was a gander and it wasn’t too long before it became apparent that it was paired to a Dark-bellied Brent Goose. This was the first occasion that I could recall seeing a vagrant Black Brant that had formed a pair bond with a Dark-bellied Brent and my interest turned to surprise when the pair came towards the edge of the flock to reveal four hybrid goslings in tow!

This was the first time that a mixed pairing had been recorded in Norfolk and, prior to this, there had only ever been one other documented British record -a mixed pair with six hybrid young was found by Barry Collins at Thorney Island, West Sussex in the early winter months of 1989 (two of these original hybrids returning during the following three winters). The same observer also found a second adult Brant (another gander, but this one was without a mate) in the same area between October 1991 and March 1992, accompanied by four juveniles that resembled berniclas (the other adult may have died on migration or on the breeding grounds, or the Brant may even have adopted the family).

In subsequent winters after 2001, two more mixed pairings with hybrid young appeared in Norfolk, both in the Wells and Holkham area. They could often be encountered, with ease, on the Pitch & Putt course near Wells Beach Road or in the fields adjacent to Lady Anne‚Äôs Drive at Holkham. These Norfolk hybrid youngsters have shown high survival rates and, in common with many of the Brent flocks, are largely site-faithful.¬† At least seven birds have returned as adult hybrids and currently, in the winter of 2012-‚Äô13, at least four are to be found in north Norfolk ‚Äď one at Burnham Overy and three in the Wells/Holkham area (with one or two of these also appearing at Cley during a period of cold weather in January).

Picking out a potential Black Brant as it walks into view amongst a flock of Dark-bellied Brents is both instantaneous and exciting – working out whether it is a pure Brant or a hybrid may take a little longer but, so long as the views and light are good, it should prove possible. The returning birds have provided an excellent opportunity for observers to familiarise themselves with the appearance of adult hybrids of known parentage. Interestingly these hybrids have (so far!) all shared a remarkably consistent appearance.

Plumage

Pure Black Brants show distinct brown hues on their body feathers. The tone can vary in its darkness but the brown hue is always present ‚Äď I tend to liken the colour to ‚Äėplain chocolate‚Äô or ‚Äėtar brown‚Äô whereas others describe the brown colour as having ‚Äėtobacco‚Äô hues. The pale flank patch usually has a striking chalky-whiteness which contrasts greatly with the rest of the dark brown body feathers. Hybrids, at first glance, can closely resemble a Black Brant, but more prolonged study will reveal some subtle differences in plumage hues that hint at the Dark-bellied influence -the body feathers have distinct grey hues and the flank patch often appears slightly ‚Äėdirty‚Äô, caused by a pale buff-grey wash.

These plumages hues can, however, be influenced by light. Bright but overcast days are particularly good for assessing the subtle plumage hues of Brent Geese.¬† Full sun can sometimes ‚Äėburn out‚Äô some of these subtleties. On very dull, overcast days assessing the plumage colours can prove problematic. Hybrids can look quite dark and, at times, the grey hues of the body feathers frustratingly difficult to see. During these lighting conditions it is worth concentrating on the back feathers that catch the light e.g. the mantle and upper scapulars. As the bird turns, these highlighted areas will often be the first to show the telltale grey hues of a hybrid. As ever prolonged observation will often provide a more accurate picture of true colour and tone. (It may be worth noting that on very dull days most pure Black Brants appear very ‚Äėblack and white‚Äô, they often appear as if the contrast level has been turned up! On such days there is very little or no distinct division between the breast and belly and this dark feathering can make the flank patch and collar especially white and dazzling.)

Neck Collars

The neck collar detail of the returning adult hybrids has varied between individuals.  When viewed from the side most birds have a large, striking Black Brant-like collar but on the majority of birds the collar is broken at the front, particularly on the upper edge (see illustration). NB when relaxed or feeding it can be difficult to correctly interpret the detail of the collar at the front, some individuals can appear to have a broad unbroken neck collar at the front and it is only when a bird is alert that the true shape of the collar can be seen.

James McCallum hybrid Brants

Neck collars of known hybrid adults ‚Äď B&C are most frequent whereas A is more unusual (2 individuals). James McCallum.

 

To date, the plumage colour hues of all of the known hybrids in Norfolk have been consistent. This has suggested that colour hue is probably more helpful than the presence of neck collar that meets at the front when identifying a hybrid.

The following photos, taken in Feb 2013, are of two adult hybrids that continue to return each winter to the Wells and Holkham area.

Hybrid One

Black brant hybrid lone bird b

This eye-catching individual readily stands out from the accompanying Dark-bellied Brents. At first glance it does look very like a Black Brant. The presence of grey hues in the body plumage and the ‚Äėdirty‚Äô wash to the rear flank-patch are indications of a hybrid.

Black brant hybrid lone bird f

In duller light the plumage can appear more contrasting and, frustratingly, the body plumage can sometimes appear to have brown hues. During such conditions this individual can appear extremely Black Brant-like, however, ¬†a greyish ‚Äėbloom‚Äô can often be visible on areas of the mantle and upper scapulars that catch the light as the bird turns.

Black brant hybrid lone bird e

In better light the grey hues and buffy/grey washed rear flanks area much more evident making it easier to identify this bird as a hybrid.¬† When seen well, the neck collar of this individual is obviously broken at the front. (See Fig ‚ÄėC‚Äô in the illustration of neck collar patterns)

Hybrid Two

Black Brant hybrid paired g

This bird has a striking collar. (The collar usually appears unbroken but, at very close range, it has tiny dark flecks eating into the upper edge, immediately below the bill.)

Black Brant hybrid paired e

In spite of the bold neck collar this bird is easier to identify as a hybrid due to the paler greyer hues of the body plumage and the obvious buffy/grey wash to the flank patch.

Black Brant hybrid paired j

In brighter light the Dark-bellied Brent influence is clear to be seen. In the winter of 2012-13 this bird returned paired to a Dark-bellied Brent, with a gosling in tow. The bird’s behaviour showed it to be a gander and it would readily threaten any of goose that wandered too close to his mate and young.

Black Brant hybrid paired l

Hybrid gander paired with Dark-bellied Brent and gosling. This family has spent most of the winter at Lady Anne’s Drive, Holkham. The Brent flock with which they associate often fed close to the road allowing close views and the opportunity to obtain excellent photographs. The resulting images may well represent the first documentation of definite F2 hybrid.

Black Brant hybrid paired f

In terms of plumage the 1st winter F2 gosling shows strong similarities to that of a Dark-bellied Brent. The neck collar is perhaps more striking than an average 1st winter Dark-bellied but it is not exceptional.

Black Brant hybrid paired F2 juv

Living in the heart of a traditional wintering ground of Dark-bellied Brent Geese it has been possible to get to know many of the local flocks and to watch them in a variety of weather and lighting conditions. This privileged situation has proved invaluable for regularly sharing observations and thoughts with other local observers, notably Andrew Bloomfield, Mark Golley and Richard Millington.

Further thoughts¬†– Vagrant Black Brants in Norfolk can vary in the darkness of their body feathers, not all are distinctly ‚Äėblack and white‚Äô and it is not uncommon to see a distinct division between the brown body feathers and the blackish neck, (as discussed above, light conditions will, of course, have a great influence). The presence of a neck collar unbroken at the front is often a requirement of an ‚Äėacceptable‚Äô pure Black Brant. It is now clear that an unbroken collar doesn‚Äôt exclude a hybrid Black Brant X Dark-bellied Brent.¬† The question that has to be asked is – how variable are the neck collars on pure Black Brants, particularly during the winter months?¬† (I have seen a Black Brant in Alaska in early summer with a neck collar that only met at the front on the lower edge). I guess that the answer can only come from those with experience of Black Brants within their native range.

James McCallum

Many thanks to Mark Golley for reading through the first draft and commenting on the text.

thumb

Grey-bellied Brant

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 orientalis, 13th November 2013 North Lagoon, North Bull Island, Co. Dublin. Niall Keogh.

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 orientalis, 13th November 2013 North Lagoon, North Bull Island, Co. Dublin. Niall Keogh

apparent Grey-bellied Brant, Branta (bernicla) nigricans, 13th November 2013 North Lagoon, North Bull Island, Co. Dublin. Niall Keogh

Brent Geese of 4 kinds…

Martin Garner

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

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. 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.)

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 ‚ÄėGrey-bellied Brant‚Äô 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‚Äôt have to wait long.

apparent male Grey-bellied Brant, Branta orientalis, with Pale-bellied Brent Geese,  Tyrella, Co. Down, April 2001. Martin Garner

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 ‚Äėlook for‚Äô 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‚Äôs‚Äô 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‚Äôt have written the script!

apparent adult female (centre) with 2 juveniles, Grey-bellied Brant  Branta orientalis, Tyrella, Co. Down, April 2001. Martin Garner

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.***

 

Brent Geese of Four Kinds – Frontiers in Birding (2008)

 

What is a Grey-bellied Brant?

Matt Silk

Some science…

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).

!cid_87abbe2c-540a-4a01-b70b-e41b0a7a64b0

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) ‚Äď with this variability presumably linked to where in the breeding range they are from‚Ķ

‚Ķfingers 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 ‚Äď 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 ‚Äď as everyone will know ‚Äď 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:

Migration Patterns of Grey bellied Brant

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 ‚Äúinherit‚ÄĚ the wrong flyway and end up as a vagrant. This is why vagrant geese often turn up year after year in the same sites ‚Äď 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 ‚Äď 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)….

References:

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.

Matt Silk

 

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apparent Gray-bellied Brant. 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.

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.

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.

Orange and Pink bills on White-fronted Geese

Seaton Common, January 2012

n.b. the videos below are quiet¬†acceptable¬†on full screen mode, if you like that sort of thing (click little square¬†brackets¬†on bottom right corner when you ‘play’)

Gull Masterclass on 21st Jan- bit more challenging, chiefly due to winds and sometimes bright sunshine. Still excellent company from appreciative groups of guys. Early Iceland Gull, couple Mediterranean Gulls, a leucistic Herring (looking Glaucous-like at long range), lots northern argentatus Herring Gulls (inc. nice juveniles), 1st winter Lesser Black-backs (none on the last 2 events) and hopefully lots of learning.

Non-gulls were good value. Ad. male Ring-necked Duck at Cowpen, ¬†and especially the White-fronted Goose flock at Seaton¬†Common¬†was close. The 1st winter¬†Greenland¬†White-front put on great show and we picked out a 1st winter¬†European¬†White-fronted Goose¬†with what looked like¬†a¬†basal half of the bill¬†orange– another one! Seems¬†orangeness¬†may be part of the ‘plasticity’¬†of bill¬†colours¬†of young White-fronted Geese generally.

Teesside is a great area for gulls. Thanks to Toby for organising the events. These ones nr Seaton Common.

Gull Masterclass January 2012– look forward to hearing how these guys progress and what some of them might find…

1st European White-front (back, head down), adult European White-front (middle) and  1st winter Greenland White-front (front). Seaton Common, 21.1.12. Shows differences in bill colour, bill shape and amount of black on nail of 1st winters (and what messy eaters they are!)

Video shows nice comparison in head/ bill shape and especially differences in tail pattern which were very obvious in the field.

1st winter Greenland White-front (facing forward) with European White-fronts. Only a bit of black on nail on this one.

1st winter Greenland White-front (facing forward) with European White-fronts. And this is what the underside of the bill looks like.

1st winter Greenland White-fronted Goose

Orangey-billed European White-front

Should it be Russian or¬†European¬†White-front for albifrons? Didn’t notice this one before.¬†Another¬†1st winter European/ Russian with some of the bill orangey. Colour¬†is¬†most¬†concentrated¬†on base of the culmen so very obvious when bird is head on:

The video starts with this orangey- billed European White-front. The 1st winter Greenlander is just to the right and eventually comes into full view (both first winters side-by-side). The European bird has more advanced moult (2nd generation scapulars but juvenile coverts) whereas the Greenlander has mostly juvenile scaps and body feathers still. You can see differences in tail patterns again and other differences in plumage. Then I followed the European bird and orangey bill colour shows up better at end of clip.

and Mr Foxy crossed the road near Dorman’s Pool. I am sure he would like Greenland White-front for lunch.

“A brilliant and useful day [18th Jan]. For the price of a good book I learnt more than¬†hundreds of pounds worth of books could teach me.”

Adam Firth