Bird of the Week: Barnacle Goose

by Doctor Science

It's winter, which means Rare Goose Time in New Jersey if you can't get to The Shore. Finding rare birds has become much easier than it used to, as birders use online tools to show and tell about our discoveries. Earlier this week, I saw two Barnacle Geese, which were Life Birds for me (i.e. the first time I'd seen them in the wild, though they are quite common in captivity):

Barnacle Geese, seen in Twin Rivers, NJ. Photo by Larry Scacchetti, but I was there, too. Also seen the same day: Pink-Footed Goose, Northern Lapwings.

Two days later and a bit north, I saw this Greater White-Fronted Goose.

Last week, there are enough rarae aves in Central NJ to deserve a GoogleMaps guide. Many birders have gotten into the habit of documenting all their interesting sightings with photos, some taken by holding a cell phone camera up to binoculars or spotting telescope -- digiscoping. The photos can be rapidly uploaded to flickr or something similar, like the picture above.

Birders are also getting into the habit of putting our checklists up on eBird, a project of the Cornell Ornithology Lab and the Audubon Society. The idea is to be able to put our billions of hours of observations together and actually do science with them, to have all that effort be for a larger purpose, as well as being fun.

One of these purposes is to track how birds populations are faring in response to climate change. Both the Barnacle Geese and the Pink-Footed Goose that was in a nearby field breed in eastern Greenland. Many northern goose populations have been increasing in recent decades; it's not clear how much of this is due to decreased hunting and other predation on their wintering grounds (that is, in the temperate regions where most of us live), or if warming conditions in the high Arctic are the driving force.

Unnaturally rapid climate change *is* occurring, and (as predicted) high latitudes are being hit first and hardest. While goose populations are booming, we're wondering if we're starting to see less cheerful effects on other types of birds. This winter there's been an unprecedented influx of Razorbills in Florida.

Razorbills (Alca torda) flying along the shore of Miami Beach, Florida. Photo by Trey Mitchell. source

Razorbills are the largest surviving auk -- the Great Auk, the original "penguin", has been extinct since 1844.

Razorbills nest on islands in the high Arctic, and winter at sea, living on fish. They move south like this when there's not enough food on their usual wintering grounds[1]. It's looking as though the culprit is warm water:

Abnormally warm sea surface temperatures are evident in much of the Northwest Atlantic from the Mid-Atlantic states north and east toward Greenland. Temperatures from 10-15 degrees C are a solid 3 degrees C higher than normal. These abnormal temperatures are likely responsible for the unprecedented invasion of Razorbills into the waters of Florida and the Gulf of Mexico, presumably to search for better food availability.

Cold water, which holds more dissolved oxygen and carbon dioxide, is better for plankton (and thus everything that depends on it, which in the ocean is everything) than warm water is.

So while climate change boosts the Barnacle Goose, it hurts fish and the birds and mammals that eat them -- including humans. It's probably not coincidence that the Georges Bank ground fishery is collapsing disastrously: not because of overfishing (this year), but because the fish aren't there.

The indirect relationship between Barnacle Geese and fish goes back much further than that. The word "barnacle" originally referred to the goose, not the crustacean. As you may have heard, medieval writers said Barnacle Geese

are produced from fir timber tossed along the sea, and are at first like gum. Afterwards they hang down by their beaks as if they were a seaweed attached to the timber, and are surrounded by shells in order to grow more freely. Having thus in process of time been clothed with a strong coat of feathers, they either fall into the water or fly freely away into the air. They derived their food and growth from the sap of the wood or from the sea, by a secret and most wonderful process of alimentation. I have frequently seen, with my own eyes, more than a thousand of these small bodies of birds, hanging down on the sea-shore from one piece of timber, enclosed in their shells, and already formed.

The author, Gerald of Wales, was talking about Goose neck barnacles like these:

Gooseneck barnacles on driftwood, by orinoko42 on flickr.

You can see how the white "heads" and black "necks" of the invertebrates could remind him of the white-headed, black-necked birds. Goose barnacles washed up on driftwood also writhe creepily, and their feeding-filters are called cirri, from their feathery appearance. Since Barnacle Geese don't nest in the British Isles and Europe proper, but only show up in winter, you *could* argue that maybe they don't come from goose eggs at all, but grow by an alternate method.

But personally, I think this whole idea was a polite fiction, concocted to give the Irish some variety in their diet during the month of Lent. The reasoning or excuse was that Barnacle Geese, since they came from barnacles growing on wood, were clearly not really birds, but fish! And fish were legitimate to eat during Lent, so obviously Barnacle Geese were OK, too. It was particularly handy that the geese were around in late winter, just when larders were barest. How providential! Wink-wink-nudge-nudge. Basically, they'd pretend to say they believed *anything* to get out of having Fish, Again? -- which is was my husband's line if there was fish for dinner twice in a week, back when we could afford fish.

I'm planning to have a Bird of the Week every week on Wednesday or Thursday, which tells you how long I've been working on this post. The next one will be in just a few days.

Barnacle Goose (Branta leucopsis), by John James Audubon. Although they don't actually occur regularly in North America, Audubon included them because:

Several old gunners on the coast of Massachusetts and Maine, who were Englishmen by birth, assured me that they had killed Bernacles there, and that these birds brought a higher price in the markets than the Common Brant Geese. The Prince of Musignano states in his Synopsis that they are very rare and accidental in the United States, and Mr. NUTTALL says that they are "mere stragglers" there. For my part, I acknowledge that I never met with one of them, either along the coast or in the interior, although I have seen beautiful mounted specimens in various parts. Being neither anxious to add to our Fauna, nor willing unnecessarily to detract from it, I have figured a pair of these birds, with the hope that ere long, the assertion of the gunners, and those of the authors above mentioned, may be abundantly verified by the slaughter of many Geese.

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[1] does it strike anyone else as weird that there are fishing "grounds" in the ocean? Ok, just me then ...

Comments

[Countme-In]

"[1] does it strike anyone else as weird that there are fishing "grounds" in the ocean? Ok, just me then ..."

No, that's odd.

There's a dating/hookup site, I'm told, called "Plenty Of Fish". The frequenting of which, for the wrong people, again I'm told, could be "grounds" for divorce.

One would bait one's hook and cast one's line, I venture, perchance to trawl, but one fears there would be no bites. Or too much biting, maybe.

But sometimes one just needs a "chum", etc, etc. Then one comes to believe there should be strict fishing limits imposed by some international body, a phrase fraught in and of itself if we're talking about Virni Lisi, which we aren't.

I once thought "Happy Hunting Grounds" was an evocative name for the afterlife despite being encrusted with cliche, though one (the rhetorical one) also wondered where the animals' spirits went on from there. Back here, again?

Until the NRA got hold of it and changed it to "Happy Self-Defense Grounds" and now worse, "Happy High Volume Magazines with Armor-Piercing Ammo To Fight Government Tyranny Grounds".

One would expect, at the very least, succinctness in the afterlife, but it seems we're going the other way.

[byomtov]

"Aah. There's the old coffee factory. When I was a boy I used to play on the grounds."

- From a Marx Brothers movie, IIRC.

[Matt Fraker]

I'm not so sure how common Barnacle Geese are in captivity in North America. I've just started working on a little investigation into that ... and so far, finding any for sale is quite difficult. There are several breeders who have them in their stock list, but don't actually have any on hand.

After I'm done interviewing as many breeders as possible, I'll report my findings in an article ... somewhere. In any case, it does seem a bit odd that almost every single Barnacle Goose that shows up here, does so exactly when and where you would expect such a vagrant to occur. If they were mostly escapees, I would expect them to be spread around more, both in terms of space, and time of year.

[Flooring Calgary]

I'm very tired! We had some construction here last week and through most of the weekend. All of the carpet came out of the stairwell and the upstairs landing and the guest room