BIRDING BY HINDSIGHT: A Second Look at Honkers
On a recent tour in Manitoba, one of the participants was trying unsuccessfully to give directions to a bird: "It's right over there, next to the Canada Goose." When one of the others said she couldn't see it, my linguistics lesson from earlier in the tour must have been recollected, and the directions were quickly amended: "It's next to that Honker." Now they were speaking the same language, and the reply was predictable: "Oh, now I see it!"
I suppose it would be OK to try and impress your listeners by calling it a Canadian Honker, but don't call it a Canada Goose unless you want to sound like some eastern big-city tourist. For any respectable Minnesotan or other Great Plains resident, after all, a bird name like Honker is as proper and appropriate as Chicken Hawk, Hoot Owl, and Sea Gull.
Or at least it used to be. I recently returned from my annual July trip to Nova Scotia and Newfoundland with mixed feelings. On one hand, I was ready to enthrall readers of this column with ID insights into what we found: ptarmigans (boy, are those females hard to tell apart, and there are Minnesota records for both Rock and Willow), Bar-tailed Godwit (at first we naturally passed it off as a Hudsonian – I wonder if we've done that here), skuas (there actually are skua records in the north-central U. S., but were they Great or South Polar?), and Bicknell's Thrush (no, they aren't supposed to be here, but how do we know for sure since all their field marks overlap the Gray-cheeked's?).
On the other hand, just like during other tours, I had worries I might have missed something while I was gone that I needed for my Minnesota list. My concern was unfounded, of course. Not only didn't I miss anything, but I apparently gained a bird without lifting a finger to the focus wheel on my binoculars. By executive decree of the American Ornithologists' Union (i.e., the 45th Supplement to the AOU's Check-list as published in The Auk 121:985-995), there is now a second species of "Honker" on my list.
Or should I say "Cackler"? It seems those Mallard-sized, short-necked, stubby-billed geese with the high-pitched cackling calls which migrate through Minnesota to and from their Arctic breeding grounds have now been split from that big ol' honkin' Canada Goose (Branta canadensis) and declared a distinct species: Cackling Goose (Branta hutchinsii).
Goody. So now what are we supposed to do? It's not that simple once you stop and think about it, and the questions start to accumulate:
Q: Why the silly name Cackling Goose?
Probably because the AOU scientists (and perhaps the geese themselves) are cackling with glee as we lowly listers in the field try to figure out which species of goose we're really looking at. A much better and more logical name would have been Tundra Goose, since these geese are mostly tundra nesters. And, besides, it's one of the English names of the hutchinsii subspecies -- if Tundra was a name good enough for a subspecies, why not keep it as the species name?
Q: By recognizing just these two species of geese now, isn't the AOU saying that's all there is to it: i.e., there are simply big Canada Geese and little Cackling Geese and nothing in between?
Even though that's the implication, it's hardly that simple. As anyone who ever looks at these geese knows, there are really big ones, sort of big ones, medium-sized geese, those a little smaller, etc., etc. All this seems to be a work in progress, as many expect there will be additional splits in the not-too-distant future.
Q: How many splits?
Who knows? When you consider that authorities who have studied these geese have variously recognized from eight to 12 subspecies, it's anyone's guess. Consider as well that these subspecies are often placed in groups or populations, anywhere between two and six of them. David Sibley describes six groups in his field guide; the AOU is essentially saying there are only two (for now); and many others say there are four.
One classification of widespread acceptance, at least before this recent AOU split, has been to place 11 viable subspecies into four groups. (For more information, see Angus Wilson's website, http://www.oceanwanderers.com/CAGO.Subspecies.html.) Going generally from the largest to the smallest sizes, the groups of subspecies are listed below; note the four subspecies in boldface type which occur (at least presumably) in Minnesota. (Again, keep in mind that this arrangement is only one of many interpretations, and it pre-dates the recent Cackling Goose split. Note as well that the MOU Records Committee has yet to research and determine the Minnesota status of Cackling Goose and all the various subspecies of both Cackling and Canada geese.)
Common Group –
• canadensis / Atlantic subspecies (eastern N. America)
• interior / Interior subspecies (eastern & central N. America; includes Minnesota in summer, migration, and possibly winter)
• moffitti / Western or Moffitt's subspecies (western N. America)
Dusky Group –
• maxima / Giant subspecies (widespread; includes Minnesota year around)
• occidentalis / Dusky subspecies (western N. America)
• fulva / Vancouver subspecies (western N. America)
Lesser Group –
• parvipes / Lesser subspecies (east to Hudson Bay; includes Minnesota in migration and possibly winter)
• taverneri / Taverner's or Lesser subspecies (western N. America)
• hutchinsii / Tundra or Richardson's subspecies (arctic Canada; includes Minnesota in migration and possibly winter)
Cackling Group –
• leucopareia / Aleutian subspecies (western N. America)
• minima / Cackling subspecies (western N. America)
• Two other western forms have also been placed in this group: asiatica (the presumed extinct Bering subspecies) and the Semedi Islands form (very limited population yet to be named as a subspecies).
Q: So, what do I care about this? I just want to know which of these are now Cackling Geese and which are still Canada Geese. And what's the deal with two subspecies both being named Lesser?
According to the AOU, the new Cackling Goose species includes these subspecies: taverneri, hutchinsii, leucopareia, and minima. And the Canada Goose species still includes these: canadensis, interior, moffitti, maxima, occidentalis, fulva, and parvipes.
This may make sense to the AOU, but they've got a lot of explaining to do. Like why some in the Lesser Group (taverneri and hutchinsii) become Cackling Geese while the other in this group (parvipes) is still a Canada Goose. And consider the two subspecies which are both called Lesser: one of these is now a Cackling Goose and the other is still a Canada!
Don't ask. It's not worth it, considering all this is subject to change. For Minnesota Honker-watchers, the important things to note are that no Cackling Geese are normally here in summer, that this species can be expected statewide in migration (and probably in winter at times), and only the hutchinsii (a.k.a. Tundra or Richardson's) subspecies should occur here.
As for the Canada Goose, the subspecies interior and maxima are here in summer, and in migration and winter they can be joined by the smaller parvipes subspecies. So, that's the catch, and it's potentially a serious one: if you find a smaller goose among some larger ones, you can't simply assume it's a Cackling Goose. Consider the possibility of it just being a smaller parvipes Canada Goose. Or, for that matter, consider the simple possibility of that smaller bird just being the result of normal size variation within the (sub)species.
Q: So, as was previously asked, now what are we supposed to do? How do we determine what the status of Cackling Goose really is in Minnesota, and how do we avoid misidentifying smaller Canada Geese as Cacklings?
Who knows? The AOU didn't say, and there has been next to nothing in any ID references about what the field marks really are. After you consider the season and range, how different do the body size, neck length, bill shape, and voice have to be before it's a legitimate Cackling Goose? What else is there to look for?
Until more information is forthcoming, it may help to take notes on some of these features which can differ from goose to goose. While none of these field marks is yet known to be definitive for either species (or any subspecies), a combination of these might eventually prove to be so:
- Head shape (roundest on minima Cackling);
- Chin strap shape and width;
- Presence/absence of black under bill separating white on chin strap;
- Presence/absence of white ring below black at base of neck;
- Darkness/paleness on chest and underparts;
- Presence/absence of white forehead patch.
* * *
I suppose my original plan to write about ptarmigans, godwits, skuas, and thrushes will have to wait. In the meantime, let's just sit back and wait for the lifers to accumulate without leaving home. With as many as 12 Canada Goose subspecies recognized by some, I expect to add a dozen or so new species to my list, faster than you can say "Semidi Islands."