a.k.a. Canada Geese.
Got a new book for Christmas. It’s on Canada Geese or perhaps more helpfully known as the ‘White-cheeked Geese’ complex by Bertin W Anderson. It’s a follow-up to Hanson’s scary; compelling and controversial work published posthumously a couple of years ago. A chapter in ‘Frontiers in Birding’ is based on Hanson’s work. Andrew Harrop sent me his very useful summary of both Hanson’s work and the new work by Anderson. Thanks Andrew- I was too scared to start reading it! Headlines include the demise of the name ‘parvipes’ and the continued view that there are a lot more than just 11 ‘Canada Goose’ taxa, a number of which occur in the UK. I feel some folk would rather just stick hands over ears and hope this would go away. It won’t. It can’t. The 11 taxa/ 2 species approach doesn’t make sense of what’s observable. Should I get ready to hear about claims of Rufescent Arctic Goose and Aleutian Goose on the bird news services?
For fun! A Canada Goose showing some characters of Giant Canada Goose old ssp. maxima (once considered extinct but rediscovered by Harold Hanson)- it’s part of the Canada Goose flock at Rother Valley C.P. I think its Mark Reeder’s favourite bird.
Notes on Anderson
(by Andrew Harrop)
Taxonomy of white-cheeked geese as proposed by Anderson (2010)
Reference: Anderson, B.W. 2010. Evolution and taxonomy of White-cheeked Geese. AVVAR Books, Blythe, California.
Bertin Anderson worked with Hanson in bringing Hanson’s two volumes to publication. Here he presents his own taxonomic conclusions (summarised in the table below). Like Hanson, he does not recognise parvipes, for reasons discussed on pp. 267-8 and pp. 274-5.
In total, Anderson recognises 15 species and 181 subspecies. 9 species and 98 subspecies correspond to Greater Canada (sensu AOU/BOU), and 6 species and 83 subspecies to Lesser Canada/Cackling Goose.
Anderson’s proposed taxonomic arrangement:
|Scientific name||English name (BOU/AOU ‘Greater Canada’)||No. of subspecies|
|Branta dawsoni||Dawson White-cheeked Goose||23|
|B. akimiskiae||James bay WCG||1|
|B. kinojeae||Boreal Forest WCG||11|
|B. tetonensis||Rocky Mountain WCG||4|
|B. deltensis||Columbia River Delta WCG||9|
|B. canadensis||Pale-mantled WCG||13 incl canadensis, maxima|
|B. basinensis||Basin WCG||4|
|B. occidentalis||Dusky WCG||21 incl interior|
|B. chipewaynensis||Lower Tundra WCG||2|
||(BOU/AOU ‘Lesser/Cackling Canada’)|
|B. hutchinsii||Pale-breasted Arctic Goose||21 incl hutchinsii|
|B. fossi||Barred Arctic Goose||14|
|B. clarkei||Yukon Arctic Goose||16|
|B. leucopareia||Brown Arctic Goose||9|
|B. aleutianensis||Aleutian Goose||11 incl minima|
|B. gavini||Rufescent Arctic Goose||12 incl taverneri|
Many of the methodological problems present in Hanson’s work are again present here. Like Hanson, Anderson did not undertake any genetic work (though he does include a discussion on pp. 254-8). Nonetheless he presents much food for thought in a clearer and more consistent way than Hanson. One point which needs prompt attention is that continued recognition of parvipes is highly questionable.
AHJH (Andrew Harrop), January 2011
Me here (MG) : Certainly one of my favourite white-cheeked goose encounters in the UK. a ‘Cackling Canada’ (old ssp. minima) at Caerlaverock WWT– watched migrating west with the Barnacle Geese from Svalbard, off the coast of N. Norway. They are monster migrants of the pacific. Surely they can straggle occasionally to Western Europe?
Notes on Hanson
(by Andrew Harrop)
Hanson, H.C. 2006. The White-cheeked Geese: Taxonomy, Ecophysiographic Relationships, Biogeography and Evolutionary Considerations. Vol. 1 Eastern taxa. Avvar Books.
Hanson, H.C. 2007. The White-cheeked Geese: Taxonomy, Ecophysiographic Relationships, Biogeography and Evolutionary Considerations. Vol. 2 Western taxa, Biogeography and Evolutionary Considerations. Avvar Books.
According to my calculation, Hanson recognises six species and 217 taxa as follows:
|Branta CanadensisCanada Goose||92 races incl. canadensis, interior, moffiti, occidentalis, fulva|
|Branta maximaGiant Prairie Goose||10 races|
|Branta “lawrensis”Ontario Goose||monotypic|
|Branta hutchinsiiArctic Goose||97 races incl. hutchinsii, taverneri|
|Branta leucopareiaAleutian Goose||16 races incl. leucopareia, asiatica|
|Branta minimaCackling Goose||2 races|
Hanson includes taverneri in hutchinsii. parvipes is not recognised; Hanson comments that the type of parvipes is a wing-clipped specimen ofB. hutchinsii in poor condition from Vera Cruz, Mexico which would be ‘difficult to associate… with a fresh series of skins of any race of similar size’.
AHJH (Andrew Harrop), May 2010
2 different (old money) Richardson’s Canada types, Caerlaverock WWT, Tristan Reid. Certainly ‘Arctic Geese’ but we seem to get different taxa or subspecies of Arctic Geese (as per Anderson) in the UK.