Tuesday, March 20, 2007

Barnacle Goose

On this day in 1926, George Hix found a Barnacle Goose at Overpeck Creek in Bergen County. "Over a score" of others saw the goose; on 21 March 1926, the unlucky bird was collected (Cruickshank 1942). For a time, the specimen was thought to be lost, but it has resurfaced in the collection of the US National Museum (Hanson 2005). The bird was thought to be unusually tame, which cast an added measure of doubt on the bird's origin.

Welcome to the contentious world of the Barnacle Goose, the goose that birders love to hate. Although it shows a marked pattern of occurrence similar to what one would expect from genuine vagrant waterfowl, it is also kept in captivity. On the third hand, Eurasian Wigeons and Tufted Ducks are also kept in captivity; the Barnacle Goose happens to be the species that has had the "escape" term stick to it like glue. One reason for this is the existence of a notorious family of Barnacle Geese that were released by a waterfowl collector on White Rock Island in Nova Scotia and then proceeded to turn up in various places in the Northeast as they migrated (including NJ).

It has long been birding conventional wisdom that any birder who counted a Barnacle Goose on his or her list was no better than someone counting known exotics. Now, however, the pendulum seems to be swinging back a bit. Wild goose populations have exploded recently; the Barnacle Goose is but one of several species currently enjoying increased numbers. The winter of 2001-2002 saw a positive "flight" of Barnacles across the Northeast, although NJ got only one record from this influx. The Massachusetts Avian Records Committee (MARC), when considering a record of a bird from this flight, voted to add the species to the state list without qualifiers about origin (Rines 2003).

I could go on and on about Barnacle Geese (and did, in Hanson 2004-2005). The deeper one looks, the more interesting the quirks of conventional wisdom get. Tameness, it turns out, has been used not only to argue against the wild origin of Barnacle Geese, but FOR it as well (Tufts 1986). There is nothing wrong with taking a conservative attitude toward waterfowl origin, but if that is the case, why do we tend to doubt Barnacles but give Eurasian Wigeons a free pass? With little hard knowledge apart from known banded European birds (one of which was shot in Ontario in fall 2005), it is possible for two intelligent people to look at the same evidence and come to opposite conclusions about a Barnacle Goose's origin.

To conclude on a regrettably personal note, the sketch above is of a Barnacle Goose I found at NJ Audubon's Plainsboro Preserve on a day when I was really in the neighborhood to attend to some business before moving to Plainsboro. This goose was one bird in a winter with a good bunch of NJ Barnacle Goose records. I already had a legitimate Barnacle Goose on my life list from southern Finland in 1999. I'd seen another in eastern Pennsylvania in 2000. But I have to admit that such a good find on such an opportune day went on my personal NJ state list. Ever since then, I've had a weakness for Barnacle Geese. But that doesn't mean you have to count them if you don't want to.

Hanson, Jennifer W. 2004-2005. Status of the Barnacle Goose (Branta leucopsis) in New Jersey. New Jersey Birds 30:86-92.
Rines, Marjorie. 2003. Seventh Annual Report of the Massachusetts Avian Records Committee. Bird Observer 31:95-103. link here
Tufts, Robie W. 1986. Birds of Nova Scotia. 3rd edition. Nimbus Publishing/Nova Scotia Museum, Halifax, NS. link here


Anonymous said...

Long a barnacle skeptic, you can bet I counted the Hamilton bird in 2002 (http://www.dvoc.org/DelValBirding/Places/place034.htm), and I've been a lot less forgiving of reports since -I- saw one!
This is a great and very useful entry in your 'blog', Jennifer, thanks!

Anonymous said...

What I _meant_ to say, of course, was that I've been a lot MORE forgiving of reports since.
A bit muddly after just returning from a great Nebraska tour,

Jennifer Hanson said...

Hi Rick,

Thanks! I've been waiting to get struck by lightning since I publicly admitted that I count Barnacle Goose on my NJ list, but nothing has happened yet. Whew. It really is fascinating to look at the things that creep in to fill the gap when there is little hard evidence about a species' occurrence. Of course, maybe the Barnacle Goose has been doomed to be misunderstood ever since Geoffrey of Wales asserted that it came from barnacles...

Rob said...

There was a Barnacle Goose in early 2002 in Fairfax County/City of Alexandria, Virginia ... which I count as my life Barnacle Goose. It was as wild as the Canada Geese it was with. Now if one would only show up in DC.

Jennifer Hanson said...

Hi Rob,

Oh, good, another Barnacle counter comes forward. Maybe there are a few of us after all. :) Good luck with getting it in DC!

Rob said...

Thanks, Jennifer. There is a Barnacle that shows up about 50-60 (?) miles from DC in Kent County, Maryland, in the fall for a few days and in the spring for a few more days. I think this is the second winter that's happened. Of course I have missed seeing it.

Jennifer Hanson said...

Interesting. That definitely sounds like a migrant.