Verification of Unusual
Rec. # 2009-31
|Scientific name:||Branta hutchinsii|
|Date:||19 Dec 2009|
|Length of time observed:||10 minutes|
|Location:||Logan River Golf Course, Logan|
|Distance to bird:||~30 yards|
|Optical equipment:||Nikon 60mm Sky and Earth spotting scope with 20x eyepiece, Nikon 10x42 Monarch binoculars|
|Weather:||Partly cloudy, around freezing|
|Light Conditions:||Fading evening light|
|Description: Size of bird:||Larger than Mallards, smaller than nearby Lesser Canada Geese (Branta canadensis parvipes)|
|(Description:) Basic Shape:||Goose shape|
|(Description:) Overall Pattern:||"White-cheeked goose" pattern. Details below.|
|(Description:) Bill Type:||Shorter than that of Canada Geese|
Field Marks and
These geese were easily identified as a "white-cheeked goose" (Canada or
Cackling) by their 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. These birds had smaller, stubbier bills than
the Lesser Canada Geese with which they were associating. Their necks were
shorter and stockier. The Cackling Geese's heads were smaller and more blocky
than those of the Lesser Canada Geese (i.e. shorter from the base of the bill to
the back of the head and with more abrupt angles in the profile). The culmens of
the Cackling geese were straighter and shorter than those of the Canada Geese,
and formed a more abrupt angle with the forehead. The foreheads were steep and
formed a more abrupt angle to the crown. The flanks were about the same color as
the color of the wings, perhaps slighty paler. Body size was significantly
smaller than the Lesser 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
determined for these birds.
(See photos. The Cackling Geese are labelled A, C, D, and E. A Lesser Canada Goose [B. c. parvipes] is labelled B.)
|Song or call & method of delivery:||
None known to come from these individuals.
|Behavior:||Flying in to roost on a small pond at dusk with 109 Canada Geese. Some foraging at the edge of the ice that had formed on the pond. These four Cackling Geese were first observed in two pairs which came together during the period of observation and stayed as a group of four among the Canada Geese.|
|Habitat:||Golf course pond, partially frozen over.|
were they eliminated:
These geese were identified as one of the smaller white-cheeked geese on the
basis of their small size, short bills, and small relatively short head (from
bill to nape). 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
these individuals. This comparison is facilitated by the fact that there were
many Lesser Canada Geese in this mixed flock, and one is shown in these
photographs. The bills of all four Cackling Geese were shorter and with a
steeper, straighter culmen (less concave) than in the Lesser Canada Geese, and
formed a more abrupt angle with the forehead. The heads of all four birds were
also shorter from bill to nape than in the Lesser Canada Geese. Finally,
although there is some overlap in body size between the largest Cackling Geese
and the smallest Lesser Canada Goose, these particular individuals were all
smaller than the Lesser Canadas which made up the majority of this flock.
B. h. minima: The bills of these birds were not as short and stubby as on a Ridgway's Cackling Goose. The breast of these birds were paler than the flanks, a condition that is reversed in B. h. minima, and these birds did not have the dark purplish-brown sheen seen in minima. The heads of these birds were also not as short and rounded as those of B. h. minima.
B. h. leucoparia: Aleutian Cackling Geese have a white neck ring which is usually quite bold. These birds did not have white neck rings, and were also paler than most B.h.leucoparia.
B. h. hutchinsii: At least two of these birds and perhaps three were Richardson's Cackling Geese. First, their heads were angular and blocky (but small). This is evident in the photographs, but photographs can be misleading as posture changes and I can confirm the small, blocky head of these birds from ten minutes of observation in the field as well. Also, the crowns of these birds had a peak towards the rear of the head. The breasts of these birds were about the same shade as that of the Lesser Canada Geese they were associating with, or perhaps slightly lighter.
B. h. taverneri: In the field we identified two of these four birds as Taverner's Geese. The breasts of these birds were slightly darker than that of the Lesser or Richardson's Geese. Their head shape was consistent with B. h. taverneri, being short but somewhat more rounded than that of B.h.hutchinsii. Their bills were also slightly longer than those of B.h.hutchinsii but still significantly shorter than the B.c.parvipes when compared directly. I was somewhat surprised to find that these differences do not seem as apparent in the photographs as they did in the field. I believe that goose labelled "A" represents one of these two presumed Taverner's geese. Photo 1 shows the slightly longer bill of this individual and also shows the rounded head well, but the breast is not visible for comparison in this photo. Photo 2 again shows the slightly more rounded head and longer bill than the other Cackling Geese, but still a rounder head and shorter neck with stubbier bill than the Lesser Canada Goose labelled "B". (Photo 1 is misleading for B's head and bill proportions as the bird's head is turned away from the camera, although it's neck and body are still visibly longer than those of the Cackling Geese photo.) I'm not sure which of the other three Cackling Geese in these photographs is the other Taverner's, as they all appear to fit B.h.hutchinsii well from these two photographs. Perhaps we isidentified one of the individuals to subspecies in the field, or perhaps these two photos both obscure the traits of one of the Taverner's geese in such a way to make it look like another Richardson's. Regardless, I believe all four of these Cackling Geese can be clearly discriminated from Canada Geese, including Lesser Canada Geese such as the one shown in these photographs.
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 State, where they commonly overwinter and where I used to live. I have seen nineteen Cackling Geese on eleven occassions in Utah. (Although some of these nineteen were likely multiple observations of the same individual, I believe I have seen a minimum of 14 unique individuals in the state).|
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 Dr., Logan UT 84341|
|Observer's e-mail address:||Ryan@biology.usu.edu|
|Other observers who independently identified this bird:||Ron Ryel and Andy (I don't know his last name).|
|Date prepared:||19-20 Dec 2009|