Verification of Unusual
Rec. # 2009-02
|Scientific name:||Branta hutchinsii|
|Date:||1 Feb 2009|
|Length of time observed:||10 minutes|
|Location:||Sam Fellow Road and 4600N|
|Distance to bird:||~50 yards|
|Optical equipment:||Nikon Sky and Earth 20x Spotting scope, Pentax Optio W30 digital camera|
|Weather:||cool, near 0 degrees C, partly cloudy|
|Light Conditions:||Direct late-afternoon sunlight|
|Description: Size of bird:||Considerably smaller than nearby Canada Geese|
|(Description:) Basic Shape:||small goose shape|
|(Description:) Overall Pattern:||White-cheeked Goose pattern: brown body and wings, black neck and head, white cheek patches, white base of tail, black tail|
|(Description:) Bill Type:||Small stubby bill reminiscent of a Ross's Goose.|
Field Marks and
This goose was easily identified as a "white-cheeked goose" (Canada or Cackling)
by its brown body and wings, black tail, white tail base and undertail coverts,
black neck and head, and white cheek patches extending up from under the chin
onto the face. This bird had a smaller, stubbier bill than the Great Basin
Canada Geese with which it was associating. Its neck was shorter and stockier.
Its head was smaller and more rounded (i.e. shorter from the base of the bill to
the back of the head). The culmen was straighter and shorter than the Canada
Geese's, and formed a more abrupt angle with the forehead. The forehead was
steep and rounded to the crown. The breast was slightly darker than that of the
Great Basin Canada Geese. The flanks did not differ significantly from the color
of the wings. Body size was significantly smaller than the Canada Geese in all
dimensions (shorter in total length, shorter in breadth, and smaller in volume).
The presence or absence of a black "chinstrap" bisecting the white cheek patches
under the throat was not observed in this individual.
(See photos. The Cackling Goose is at front right of each photo.)
|Song or call & method of delivery:||None known to come from this individual|
|Behavior:||First loafing in a snowy field, then flew to an area of the field that was recently spread with manure and foraged there with 500 Canada Geese.|
were they eliminated:
This goose was identified as one of the smaller white-cheeked geese (Branta
canadensis parvipes or Branta hutchinsii) on the basis of its small size, short
bill, and small rounded head. Separating the Lesser Canada Goose, Branta
canadensis parvipes, from the larger two Cackling Goose subspecies, Taverner's
Cackling Goose (Branta hutchinsii taverneri) and Richardson's Cackling Goose (Branta
hutchinsii hutchinsii) can be difficult but I believe this distinction can be
made for this individual. The bill was shorter and with a steeper, straighter
culmen (less concave) than in Lesser Canada Geese, and formed a more abrupt
angle with the forehead. The head was also shorter from bill to occipital area
than in Lesser Canada Geese. Finally, although there is some overlap in body
size between the largest Taverner's Cackling Geese and the smallest Lesser
Canada Goose, this particular individual was smaller than the smallest Lesser
Canada Geese I have se!
en in Utah.
This bird may not be confidently identifiable to subspecies, but I believe this was a Taverner's Cackling Goose and will present the reasons for that belief by addressing each of the four subspecies of Cackling Geese:
B. h. minima: The bill was not as short and stubby as it would be on a Ridgway's Cackling Goose. The breast of this bird was paler than the flanks, a condition that is reversed in B. h. minima, and this bird did not have the dark purplish-brown sheen seen in minima.
B. h. leucoparia: Aleutian Cackling Geese have a white neck ring, which was absent in this individual. Also, many B. h. leucoparia have a black gular stripe that is so bold as to be visible from the lateral view. I did not get a ventral view of the chin of this bird, but it did not have a gular stripe that was bold enough to be visible from the lateral view.
B. h. hutchinsii: I am not confident that Richardson's Cackling Goose can be safely eliminated as a possibility for this bird, but I will addres several points that I feel argue against it being a Richardson's Cackling Goose. First, the head was more rounded than usually seen in B. h. hutchinsinii, and did not have the angular, blocky (but small) head typical of that subspecies. This is evident in the photographs, but photographs can be misleading as posture changes and I can confirm the rounded head of this bird from ten minutes of observation in the field as well. Also, the head of this bird had a peak towards the front, where B. h. hutchinsii typically has a peak towards the rear of the head. The breast of this bird was darker than that of all of the Great Basin Canada Geese, although not dramatically so. In certain angles, the breast appeared the same color as the Great Basin Canada Geese, which is consistent with a relatively dark B. h. hutchinsii or a relatively pale B. h. taverneri, however it generally appeared darker than the B. c. moffitti.
B. h. taverneri: I believe this goose was a Taverner's Cackling Goose, albeit not exactly an entirely typical one. The breast of this bird was paler than the average Taverner's goose, but still within the expected range of variation and darker than expected for most B. h. hutchinsii. The bill of this bird was smaller than most photos I have seen of B. h. taverneri, which helps confirm that it was not a Lesser Canada Goose, but also supports B. h. hutchinsii as an alternative identification. The head shape was generally consistent with B. h. taverneri, being rounded like B. h. minima but larger overall.
this & similar species:
|I have seen tens to hundreds of thousands of Canada Geese around the continent. I have seen hundreds of Cackling Geese in Washington, where they commonly overwinter and where I used to live, and several in Utah.|
Mlodinow et al. 2008. Distribution and Identification of Cackling Goose (Branta
hutchinsii) Subspecies. North American Birds 62:344-360.
Plus the webpages cited in record 2008-35.
|Description from:||Notes taken at time of sighting|
|Observer:||Ryan P. O'Donnell|
|Observer's address:||1098 Crescent Drive, Logan, UT 84341|
|Observer's e-mail address:||Ryan@biology.usu.edu|
|Other observers who independently identified this bird:||(none that I know of)|
|Date prepared:||3 Feb 2009|