On "Subspecies" of the Canada Goose

by Gerry Rising

(This is an article submitted to The Kingbird in 2003. It is a revised version of an article that appeared in The Prothonotary 68 (12):131-132.)

I am concerned about the interest being expressed by New York State observers in the smaller Canada Geese occurring here. These are, according to them, Branta canadensis hutchinsii, a subspecies termed the Hutchins Goose in Bent's Life Histories of North American Waterfowl. (Elsewhere it is named Hutchins', Hutchins's or even Richardson's Goose.) I certainly do not argue with this identification, but I wince each time I see these birds reported. In this article I explain why.

But first an aside: I have no problem with our differentiating the Horned Lark and Palm Warbler subspecies or the various hybrid forms of the Golden-winged and Blue-winged Warblers. There are, I believe, good arguments for these identifications. However, with game birds and in particular Canada Geese, I urge caution in raising this issue of races.

Now to my point: Surely most of us would agree that we have today a few too many Canada Geese soiling our ball fields and corporate lawns, ruining our golf course greens and driving other species out of our marshes. What we should understand is that interest in the various forms of Canada Geese contributes to this overpopulation.

How many birders realize that goose-hunting seasons have been severely curtailed because of concern for another so-called race of Canada Goose, B. c. maxima, a subspecies that is not even recognized by taxonomists of the American Ornithologists Union?

These larger geese were popularized by Harold C. Hansen's The Giant Canada Goose (Carbondale, IL: Southern Illinois University Press, 1965, rev. 1997). In this book, which has been termed by one wildlife manager "one of the finest waterfowl monographs ever written," Hansen makes the case for protecting these big geese ã hunters' favorites for obvious reasons ã through season restrictions: "Adjustment of the opening and closing dates of the hunting season," he says, "is one of the principal means of regulating the size and selectivity of waterfowl kills. It should, therefore,...be pointed out that because the fall migration movements of the giant Canadas are fully a month behind the migration of the race interior, late hunting seasons will tend to jeopardize stocks of maxima...."

And so, at least partly influenced by Hansen, goose seasons have been reduced. As my Ohio colleague, Bill Whan, says: "It is an article of belief among wildlife officials that their precious maximae 'migrate' a month later than other forms. Thus here in Ohio we have an 'early goose season' in September (coinciding with the teal season pretty much), which is ballyhooed as a way to control nuisance flocks of resident geese without imperiling any of the truly wild and migratory Canadas, which allegedly come through beginning in mid-October." But even this goes wrong. Bill continues: "This year the truly migrant race interior - with orange collars - (universally recognized as genuinely in trouble) came through a bit 'earlier' than usual...to be greeted by a hail of shot."

Hanson fought hard to have the American Ornithologists Union recognize his beloved giants, but Alexander Wetmore and his taxonomic colleagues would have no part of his arguments. The only mention of the maxima subspecies in any of the seven A.O.U. Checklists is in the 5th (1957). There it is listed as probably extinct. More important, especially as regards our local Canadas is the 6th (1983) Checklist. In it no subspecies is listed! And this note appears: "The northern populations of small Canada Geese have been variously treated taxonomically as three separate species, B. hutchinsii (Richardson, 1832) [Hutchins' or Richardson's Goose, 172.3], B. minima Ridgway, 1885 [Cackling Goose, 172.2], and B. leucopareia (Brandt, 1836) [Tundra Goose, 172.1]; as a single species under the name B. hutchinsii [Cackling Goose]; or as one or more subspecies of B. Canadensis. Consideration of the entire complex as a single species seems best for the present." (The underscoring of these important points is mine.) To bring this up to date: The 7th Checklist (1998) follows the 6th in listing no subspecies. Clearly all of these size differences are currently considered a cline.

Why, despite this, Kevin Griffith mentions B. c. maxima in the 1998 Bull's Birds of New York State escapes me. Consider, however, what he says: "Resident breeding geese probably include some of both [the canadensis and interior subspecies] and a large proportion of maxima, or 'Giant' Canada Goose." What a turn-around: from Hansen's endangered race needing protection to the lawn pests of Griffith and, as it happens, of current waterfowl managers! (pers. comm., Paul Hess) Has no one thought of the possibility that these 'giant' geese are bigger and fatter simply because they are lazy, pampered and overfed?

My point here is that attention to game bird subspecies gives wildlife managers an excuse to tamper with what I consider an already far too short goose season. While they concern themselves with niggling subpopulations, we're being inundated by the species as a whole. And we certainly don't want to provide an excuse for a season further curtailed to address the smaller numbers of hutchinsii.

An indication of just how far this race issue may be taken is found in the revised (1997) edition of Hansen's book. In it he insists on page xvii that "As a result of over 30 years of research on the taxonomy and biogeography of the white-cheeked geese, at least 186 geographic races (subspecies) of these geese will be recognized in a yet-to-be published work." He comments on this work in progress in a footnote: "The White-cheeked geese (Branta canadensis, B. maxima, B. hutchinsii, B. leucopareia, and B. minima): Taxonomy, Ecophysiographic Relationships, Biogeography, and Evolutionary Considerations. (Yet to be published.) Late in the preparation of this work on the white-cheeked geese, it was realized that the giant Canada goose (Branta canadensis maxima) was in reality a separate species -- Branta maxima -- and that it should be given a more appropriate common name -- the giant prairie goose. Seven geographic races or subspecies will be described."

He adds to this in Appendix I on pages 207-208: "The 83 races at least of Canada geese (Branta canadensis) that will be recognized by the author (Hanson, yet to be published) represent a series of staircase clines in respect to size, proportions, color, and color patterns -- that is, each racial population exhibits a discrete combination of these characters that are related to the latitude, climate, and ecology of their isolated breeding grounds. Stated another way, the mosaic of characters associated with the racial populations of white-cheeked geese are not accompanied by 'intergrades' or individuals that represent a blending of the characters of the nearest racial populations."

It is easy to be confused by all that nonsense. What he appears to be saying is that he is separating out from the Branta genus (because Brant, Branta bernicla, is no longer included in its own genus) these so-called white-cheeked geese for which he identifies "at least 186" races, 83 of which are races grouped under the species Branta canadensis. This leaves us with over 100 races that would have to be identified with new species, one of which he identifies as Branta maxima, no longer the Giant Canada Goose, but now the Giant Prairie Goose. And his "new species" has only seven of those 100 races, thus suggesting still more full species. Hansen certainly deserves some kind of prize (offered by listers?) as the champion among all splitters.

Of course this all flies in the face of John W. Aldrich's 1946 article "Speciation in the White-cheeked Geese" (Wilson Bulletin 58(2): 94-103) which identifies, among 254 museum specimens examined, only seven races, none of them maxima; and the most subspecies ever considered by an A.O.U. Checklist: ten in the 5th (1957).

I join Bill Whan in wondering if "all those goose-droppings in the water have had some neurotoxic effects" on a few game managers. Whether or not that is the case, I counsel extreme caution in calling attention to nonexistent subspecies to avoid even the possibility of contributing further to our increasingly serious Canada Goose overpopulation problem.

A final note: Despite all I have said here, it is, I believe, quite reasonable to differentiate between our tame, non-migratory geese and the wild geese that migrate through this country and Canada. What we really need is a national campaign to rid ourselves of the pests that we have created in the same way that waterfowl managers are finally seeking to control cormorants and Mute Swans ã by activities like egg-oiling and removal (a.k.a. killing). Then goose seasons could be scheduled in response to wild populations. Sadly, however, even the consideration of such actions divides our community.