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

Cackling Goose - Caerlaverock © Tristan Reid 2009

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)

References:

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

Above 4 photos: currently labelled (probably incorrectly) as Taverner’s Canada Goose, Caerlaverock WWT, January 2009, Tristan Reid

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.

3 photos above: The best we get in South Yorkshire, a dodgy mixture that look something like Giant Canada X Cackling Canada hybrid?! Broomhill Flash, March 2006.