Thursday, August 28, 2008

Taverner's Cackling Goose, Branta hutchinsii taverneri, in Connecticut.

It was my birthday. November 30, 2007. I was going to spend the day birding to see what fortune this day had to offer. After killing my battery trying to photograph Horned Larks at Hammonassett Beach State Park in Madison and spending too much time trying to persuade a state park employee to jump my battery ( I was finally successful though it took an amazing amount of pleading), I decided to head inland to the Lyman Farm Orchards and pond in Middlefield to see and the photograph a Greater White-fronted Goose reported earlier in the week by Greg Hanisek. Well, my luck was holding. The White-fronted Goose was nowhere to be found. Just before leaving, I was scanning the flock of Canada Geese there and noticed a small billed goose amongst the flock. Thinking I had found the Richardson’s Cackling Goose, Branta hutchinsii hutchinsii, that had also been previously reported, I pulled over, set up my camera, and attempted to get photos. I was amazed at how difficult it was to keep track of this goose. Normally this smaller form sticks out from the larger Canada Geese. This bird, while smaller was not really small. Likewise, Richardson’s Geese often appear frostier in the field and stand out from the darker Canadas. Again, this bird did not. I noticed it was darker breasted as well. Typically, Richardson’s Cackling Goose is the palest breasted of the Cackling Goose forms. This bird also showed a white collar between the black neck stocking and the darker breast. While most of the forms of Cackling Goose can show this, I have never noted it on any Richardson’s Goose that I have seen. I kept studying the bird as I took photos ( I would end up with about 200 images of the bird!!!). I noticed that the head was shaped differently from what I have come to expect with Richardson’s Goose. Rather than appearing square-headed with a steep forehead angle where the stubby little bill meets the head, this birds profile was more rounded, the forehead seeming to continue from the slope of the bill. The neck seemed longer as well. The rounded head on this longer neck gave me a very different impression of this bird compared to the many Richardson’s Geese I have seen. As the light was fading I was getting ready to leave but noticed one more thing that seemed strange to me. I was getting glimpses of the underside of the birds head as it fed and I kept thinking I was seeing a smudgy looking dark stripe from the base of the bill to the back of the white patch in the throat. I attempted to get some images of this but the time and the light made it tough. This gular stripe is present in most Taverner’s Geese and some other forms of Cackling Geese as well. I have never noted one on a Richardson’s Cackling Goose.
On the way home I started thinking about what else this bird could have been other than a weird Richardson’s Cackling Goose. I remembered somewhere in the dusty old archives of my memory that Taverner’s Goose, which I know primarily from its appearance in the British pages at, shows a sloping head shape. Not having the proper references with me, I made good use of my hands-free cell phone adaptor and called Nick Bonomo as he and I had recently been discussing this form of goose. I wanted to run my observation by him and see what he thought. After our conversation and after returning home to check references, I was more sure of my ID as Taverner’s Goose. I sent the images to three West Coast birders and experts on the Cackling Goose complex, I asked Steve Mlodinow, Bruce Deuel, and Larry Semo to comment on my images and written description. These guys bird the West Coast and Rocky Mountain West and have opportunity to see all the forms of Cackling Geese and all the smaller forms of Canada Geese ( this will be important to a future Birding Geek note ). In fact, I had been collaborating with Steve Mlodinow by supplying images for an upcoming article he is doing on the identification of the forms of Cackling Geese. All of them responded that they were sure that this bird was, indeed, Branta hutchinsii taverneri, or Taverner’s Cackling Goose. All of their analysis cited the bill and head shape, the size and neck length, plumage coloration, the darker breast with collar, and the dark gular stripe as being very supportive of this identification. Richardson’s Cackling Goose was eliminated in the same ways and Lesser Canada Goose, B.c. parvipes was similarly eliminated ( again, pay attention for a future Bird Geek Diary!).

Interestingly, earlier, in October 2007, a Taverner’s Cackling Goose was identified and photographed in Amhurst, MA by James P. Smith. This bird appears very similar to the Connecticut bird and questions can be raised if in fact it is the same individual. To my knowledge, this is the first documented record of this subspecies for Connecticut, possibly the first record of any sort.

I am quoting from The Birds of North America on-line account for this subspecies:

“B. c. taverneri Delacour, 1951; type locality Colusa, CA. Taverner’s (or Alaska) Goose. Breeds in low tundra vegetation along shorelines of major rivers and small braided streams, shorelines of small tundra ponds, and on islands in tundra ponds and lakes of Yukon-Kuskokwim Delta, AK; breeding on the delta restricted to inland areas beyond the influence of tides, and extending inland to the north slope (Johnson et al. 1979, Jarvis and Bromley 1998). ..
…Winters primarily in Willamette River valley of w. Oregon, lower Columbia River valley of n.-central Oregon and s.-central Washington, and n. California (Johnson et al. 1979, Gilligan et al. 1994, Jarvis and Bromley 1998, CRE). “
This account includes the Cackling Geese as tundra-form Canada Geese. Branta canadensis taverneri is now considered Branta hutchinsii taverneri in a recent split by the American Ornithologist’s Union.(A.O.U.)

I want to thank Nick Bonomo for answering his cell-phone and wondering along with me, Steve Mlodinow, Larry Semo, and Bruce Deuel for their work in sorting out this very tough ID question, and that unidentified park employee for finally agreeing that jumping my battery was not a crime.

Literature cited:

The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North America Online database:; AUG 2005.

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