Idaho Bird Records Committee Rarities Report Form

 

Species: Cackling Goose

 

Reporter: Cliff Weisse, 4125 Beaver Springs Rd., Island Park, ID 83429, 208-558-7789, cliffandlisa@octobersetters.com

 

Other Observers: none

 

Date of Observation: 2/18/2007

 

Date Report Prepared: 3/1/2007

 

Number seen: 6

 

Locality of Observation: Bruneau Duck Ponds, on the large pond visible from ID 78, north of the road, just east of the junction with ID 51.

 

Habitat: Man made pond

 

Conditions: Windy and overcast with intermittent light rain.  Distances ranged from 100 to 200 yards with Nikon Premier 10 x 42 binoculars and Swarovski 80 mm HD scope and 20-60x eye piece.  I spent approximately 40 minutes at the location which includes making a count of all birds present. 

 

Did you take notes…no

 

Did you consult a field guide or other reference work?

            no

 

Description: I believe there were two subspecies present.  There was a group of five individuals that always stayed together like a family group and a single bird that was loosely associating with Canada Geese including one probable Lesser Canada Goose.  Plumage was patterned similarly to the Canada Geese, brown upperparts, gray-brown flanks, white uppertail and undertail coverts, tan to bronze breast, black neck, black head with vertical white patch on cheek behind eye, and black bill.  The birds in the group all looked the same with no appreciable difference in size or color observed.  I’ll describe them first:

 

-Smaller than Canada Geese present with similarly colored breast, pale tannish to my eye. 

-Flanks were marked by slightly contrasting light and dark bars, similar to Canada Geese present with the exception that the light bars may have been slightly buffier, less gray, than the Canadas. 

-Necks appeared proportionately shorted than nearby Canada Geese.  I was able to compare them to several individuals as they swam through the scattered Canada Geese.

-White cheek patches were slightly narrower than nearby Canadas, although some approached these birds in width of cheek patch.

-Heads were all square, peaked at the fore- and hind-crown, not rounded as the nearby Canadas were, with steeper forehead to bill angle.  The forehead angled more abruptly upwards from the base of the bill than on Canada Goose.  This mark was easily seen in direct comparison but was obvious without Canadas nearby for direct comparison as well.

-Bills were short and proportionately thick based compared to Canada Geese.  Again this was obvious with or without Canadas nearby for direct comparison. 

 

In my opinion the pale breast and side barring indicate the subspecies richardsoni.  

 

The single individual was obviously smaller than nearby Canadas, easily picked out with 10x binocs because of the size even when the darker breast was not visible:

-Breast was bronze and darker than the Canadas that were nearby for comparison, thought not as dark as typical of minima.  No white collar was observed between black of neck and bronze of breast.

-Head square, or slightly peaked at hind- and fore-crown.  This made the head shape stand out from the rounder heads of the Canada Geese it was associating with.  The forehead/bill angle was noticeably steeper than on the Canada Geese in direct comparison but again this difference was obvious even without Canadas nearby for direct comparison. 

-Bill was noticeably shorter and deeper based than nearby Canada Geese.  There was also at least one Canada that was smaller and of a similar size to the bird described here that had a bill size that appeared intermediate between Canada and Cackling but close to Canada in shape.  I feel this individual was a Lesser Canada Goose.  Assessment of bill and head shape were made with this individual in the same scope view at times.

 

This bird differed from the above described five birds mostly in having a much darker breast which I feel indicates the subspecies taverneri.  This individual was not close enough to the group of five to compare size.

 

Behavior: Resting on water.  The birds did not forage and swam away from me when I got out of the truck, first at the east end of the pond, then on ID 78 where I was closer.  I counted 240+ Canada Geese on the pond in addition to the Cackling Geese being reported here. 

 

How and when did you positively identify the bird, and what clinched the identification for you? I first observed the single individual with binocs and noticed the dark breast and apparent smaller bill.  I suspected it was a cackling Goose and set up the scope.  The bill and head shape were immediately obvious upon viewing the bird through the scope at 60x.  I didn’t notice the group from this location but did so quickly after moving to a closer location.  The size first caught my eye through the scope so I zoomed to 60x and noticed the small bill and square head.  This group was swimming left to right through scattered Canada Geese and eventually got to where I could see all five individuals.  I checked the head/bill structure of all five birds multiple times because I wanted to make sure I was correct.  Five Cackling Geese together is new for me but apparently not unusual since family groups tend to stay together on the winter grounds.

 

How did you eliminate similar species, and what were they? The only species for possible confusion is Canada Goose, especially Lesser Canada Geese.  The key to separating Cackling from Lesser Canada (parvipes) is the bill and head shape.  Lessers have similar head and bill shape to Canada, flatter forehead to bill angle with proportionately longer and less deep based bill than Cackling.  Cackling has a short, deep based bill with steep forehead creating obviously more acute bill to forehead angle.  Cackling differs from Canada in a similar way as does Barrow’s from Common Goldeneye.  These birds all had the steep forehead and short, deep based bill typical of Cackling Goose.

 

Experience with this species: I’ve seen a few Cackling Geese annually for the last three years and thousands of Canadas annually for many years.  I did not begin to really study head and bill structure until the Cackling/Canada split was imminent.  Subsequently I’ve studied many Canadas in preparation for identification of Cackling Goose.

 

General experience birding: 14 years

 

Were photo(s), video, and/or audio obtained by you? no