BLAGDON LAKE BIRDS

Cackling Goose



Cackling Goose Branta hutchinsii (Richardson, 1832)

Richardson's Cackling Goose Branta hutchinsii hutchinsii (Richardson, 1832)

(Extremely rare Nearctic vagrant or escapee)

Richardson's Cackling Goose, Holt Bay, Blagdon Lake © Nigel Milbourne, 2011

  1. One, 1st-winter, 1st-2nd Nov. 2011 (N.R. Milbourne, R. Mielcarek et al.).

I was on my, almost, daily visit to Blagdon Lake and birding my way along from the dam to Top End when, during a count of the Canada Geese Branta canadensis at about 1120 hrs, I came across an exceptionally small individual with a small group of larger birds not more than 100 metres away from where I’d parked my car. I fully expected it to be the small bird I’d seen on odd occasions in May and June (a hybrid Barnacle B. leucopsis x Cackling Goose, probably B. h. minima) but the neck sock and breast were completely different. I started to make a few notes and rang Keith Vinicombe, then Richard Mielcarek to alert them of a small Canada / Cackling Goose. Richard came over but by the time I’d been home to get my camera and he’d arrived the bulk of the flock, including some Barnacle Geese Branta leucopsis, had swum across the lake to the North Shore. Richard and I went over to look at the bird in more detail, take some combined notes and get some photos. It had sidled ashore and walked over to the Barnacle Goose flock but got a bit of a hard time from one individual, so fed on its own close by. The flock then decided to go back across the lake, so we went back around to view them from Green Lawn where I’d originally found it, and I got some close-up shots before we both went home for lunch and to do a bit of internet research into Cackling Goose subspecies identification features. Richard rang me while I was reading through the literature and suggested that it looked quite good for Richardson’s Cackling Goose B. hutchinsii hutchinsii which I agreed with. So I posted some pictures on the website blog with a putative identification.
After a late lunch, I went back down to the lake and met Rupert Higgins on Rainbow Point looking at the bird. He agreed with our identification and together we noted the size to be about 10-15% smaller than the 2 Barnacle Geese it swam across to Rugmoor Bay with. Chris Stone and Keith Vinicombe subsequently arrived and although the bird was quite distant by this time, Keith also agreed with our identification. All four of us then drove across to Rugmoor and parked to scope the bird with the small group of Canada’s it had joined by this time from Peg’s Point. No sooner had we started to look at them when they all took off and flew around Rugmoor Point towards Top End and out of sight. By this time the light had gone, so we all went home.

Next morning the bird was eventually relocated at Chew Valley Lake by Richard Mielcarek shortly before it flew back to Blagdon at about 1145 hrs, when Richard rang me to say it was on its way. I found it with 2 Canada Geese in Holt Bay shortly after it arrived, but it immediately swam away from them and headed towards Green Lawn constantly calling. I was surprised to hear the call was just like a higher pitched version of the ‘resident’ Canada Geese. It joined a small group of Canada Geese on Green Lawn and while I walked around the back of my car to get my camera out it flew overhead with about half a dozen Canada’s and landed on Holt Farm fields about 150 metres away from me to feed. I took a few more pictures before it walked too far away to make photography worthwhile and it sat down on the other side of the gathering flock and became obscured. This was the last time I saw the bird at Blagdon.

Here are some notes that I published at the time the Cackling Goose (aka Richardson's Cackling Goose) Branta hutchinsii hutchinsii visited Blagdon, Chew and Torr Reservoirs. Some observers considered the breast to be too dark for a Richardson's Cackling Goose, so I emailed David Allen Sibley in the USA (author of The North American Bird Guide) to seek an authoritative view. Whilst agreeing that the breast was dark, he pointed out lots of good field marks and said "its best fit is with hutchinsii...and (referring to the breast colour) that's not far off. Some would argue that the darker color indicates taverneri, I consider taverneri indistinguishable from hutchinsii." He kindly attached a photo taken in Illinois of several hutchinsii showing variation in breast color in that subspecies. Keith Vinicombe also emailed me a photograph of a bird taken in Norfolk in 1999 that was widely regarded as being a Richardson's Cackling Goose with Pink-footed Geese Anser brachyrhynchus that also had a dark breast. As for the chances of vagrancy - well, why not? The time of arrival is exactly right, with three birds arriving in County Sligo and two on Islay, albeit with carrier flocks of Barnacle Geese Branta leucopsis. Could this bird have become detached from a carrier flock? Richardson's Cackling Goose is a long distance migrant that nests in Arctic Canada and winters mainly in Texas and Mexico, but regularly turns up on the northeast US Atlantic coast (Sibley Guides). Andy Davis pointed out that there has been a seemingly curious pattern of dispersion across North America as well at the moment with, among others, three in Ottawa the other day apparently mega-alerted. We'll keep researching, but I have agreed with Richard Mielcarek to submit a record to the British Birds Rarities Committee (BBRC), who are currently circulating records of "Cackling Geese" since it's split from Canada Goose Branta canadensis. Cackling Goose has since been accepted onto the British List, and secretary of the BBRC, Nigel Hudson, also emailed me about ongoing clarification work with the split and asked us to submit the sighting. We shall have to wait and see what the authorities decide before we find out what category this bird is accepted in and whether or not it becomes a first for the AOG area.

As to the provenance of the bird, I can offer no particular supporting information other than the timing of its arrival fits very well with natural vagrancy. I asked Brian Gibbs (Somerset Recorder) if he’d received any claims for this bird before I found it at Blagdon and he said he hadn’t. I don’t know if the bird has been seen anywhere else in the country, the slight limp might give a clue. The Gwent Birding blog also mentions a bird that looks very similar, that appeared at the same time as this one and a Greenland White-fronted Goose, and a Brant further down the Welsh coast. There is clearly an unusual movement of geese currently going on around the country, first with birds coming in from the west, and then the east, as Greylags and Tundra Bean Geese showed up on a wide front.

Bibliography (sources of information)

  1. British Ornithologists' Union (BOU) website
  2. Hudson, N. Secretary of BBRC. (in. litt.)
  3. Sibley, David Allen (in. litt.)
  4. Sibley Guides website
  5. Vinicombe, K.E. (in. litt.)

Updated 3 January, 2018