Documentation of Cackling Goose (Ridgway's)

Observer Information

Reporter:  Cathy Sheeter  2245 S Waco St,   Aurora, CO  80013
Other Observers: 

Species, Date, Time and Location Information

Species:  Cackling Goose (Ridgway's)
First Date/Time:  12/25/2013 1:48:00 PM
Last Date/Time:  12/25/2013 2:07:00 PM
Duration (total time in view):  19 minutes
County:  Denver
Specific Location:  Location Not Listed
Number:  1
Age:  Adult
Sex:  Unknown
Plumage:  Other/Unknown


Along the South Platte River

Viewing Conditions

Optics:  Carl Zeiss 10x40 Bins and Canon 7D w/ 100-400 mm camera
Distance:  60 feet
Light:  excellent

Description of the Bird

This bird was observed along the South Platte River in the company of an aproximate 3500 Richardson's Cackling Geese.  It is being submitted because it is a Minima, which is a rare subspecies in the state.

When compared to the Richardson's Cackling Geese this bird was significantly smaller, not much larger than a Mallard.  The bird exhibitted the typical chestnut colored breast with obvious sheen to it.  The back color showed feathers that were blue-gray at the base, leading into brown with a noticable pale terminal edging.  Head shape was small and very round.  Bill was extremely short and stubby.  The bird was initially sleeping, but throughout my observation time it woke up and entered the river.

Similar Species Discussion

Other Cackling Geese Species and intergrades were considered.

Richardson's are larger, have a square shaped head, longer bill and paler chest. Most of the birds in the photos with this bird are Richardson's.
Taverner's are much larger (larger than Richardson's), have a sloping forehead with longer and bulkier bill and the chest is usually grayish instead of chestnut.
Aleutians are also much larger (larger or similar in size to Richardson's) with a less round head and longer bill.  They generally show a gullar stripe and white ring around the neck, which this bird lacked.

The bird did not show any obvious signs of intergrade based on size, color and head/bill shape. All indications are that this is a 'pure' minima.

Resources Used

I consulted with Steve Mlodinow about the bird, as he has extensive experience with all races of Cackling Geese.  I also reviewed this NAB article: and this article from Colorado Birds:

Previous Experience

I have extensive experience with Richardson's Cackling Geese, and moderate experience with Taverner's Cackling Geese. My experience with Minima is pretty limited, but includes a bird found in the winter of 2012/2013 here in CO and talking in depth with Steve Mlodinow about that bird. I do not have any experience with Aleutians except what I have read and discussed with Steve.


Notes made AFTER observation

Materials Available

Photographer: Cathy Sheeter

Photos |


Date Documentation Submitted

1/27/2015 7:49:00 PM
Click left or right edges of photos to move through all; click outside image to close

Location Map

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