Canada Goose (canadensis Group)

[Scott Young]

I have recently noticed Canada Goose (canadensis Group) being listed in eBird and that generates rare bird alerts. There was a brief discussion here of Canada geese species and subspecies about 5 years ago. My limited knowledge of the current state of its taxonomy suggests that there is no clear consensus. (I may have missed this, but I would have thought genomics would have weighed in by now) I had a hard time even finding any photographs or decent descriptions.

I guess I have two suggestions/questions: 1. Shouldn't pictures be included for Canada Goose (canadensis Group) listings? If you click on this group in the eBird listing, you just go to generic Canada Goose. 2. Is there a current guide that one can use to judge variations? 

Finally, to my untrained eye, among flocks of Canada Geese, there are all sorts of sizes, so I would expect other morphological and coloring details to be essential for "fine tuning."

Thank you very much.

Scott Young

Gaithersburg, MD

[James Tyler Bell]

It's unclear why one person is listing their Canada Geese in this group when it is not on the default filters. What's wrong with plain old Canada Goose? You actually have to go through a couple of extra steps to list it. Why deal with that level of frustration to list something that shouldn't be flagged in the first place?

Tyler Bell
jtyle...@yahoo.com
California, Maryland

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[Jim Stasz]

Actually, i believe the resident Canada Geese are intergrades or hybrids of "canadensis" and "occidentalis" geese from the West. The migratory geese we get are in the "canadensis" group. The reports seem to be in error.

Jim

Jim Stasz
North Beach MD
Jls...@aol.com

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[David Gibson]

Hi all, I've been following this discussion. If any of you are interested, I wrote 2 articles not long ago about Canada Geese that could be somewhat helpful. The first was "Meanwhile the Wild Geese" and the second, "The Killdeer and the Goose." James Wilson from your great state actually helped me with the second piece. All the best,

Dave Gibson

https://birdpartner.com/

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[Tim Carney]

Extremely long response I drafted with input from Matt Hafner and Tyler Bell:

eBird HQ created a master spreadsheet of all taxa that should be on eBird checklists based on region. The master spreadsheet denotes taxa by groups A, B, and C. This determines what goes on the Maryland eBird checklist filters.

Everything in group A should be on the filters. These are the expected taxa in MD. For example, "Yellow-rumped Warbler" and "Yellow-rumped Warbler (Myrtle)" are both in Group A and are on the MD filter. YRWA is a common species across Maryland and YRWA (Myrtle) is the expected subspecies in Maryland. This subspecies is visually (and somewhat audibly) different from YRWA (Audubon's), the western form. It's also important to have Myrtle as an option because the Audubon's form sometimes occurs in MD.

Everything in Group B is subjective and up to the local reviewers to decide if they want it on the checklist or not. These taxa are expected but might be difficult to ID in the field or might not be 100% relevant to the area. For example, "Eastern Bluebird" and "Eastern Bluebird (Eastern)." Eastern Bluebird is a common species across Maryland. EABL (Eastern) is the expected form in Maryland but is not easy to separate from the other option, EABL (Mexican), which is slightly paler than EABL (Eastern) and has never been recorded in Maryland. Still, it can safely be assumed that all EABL in Maryland are EABL (Eastern) so we accept this taxon here and it is on the filters.

Everything in group C is not recommended for the filters. For example, eBird recognizes three separate forms/subspecies of Willow Flycatcher that are not visually separable in the field and barely separable by voice. Most of our birds are probably Willow Flycatcher (Eastern) but this would be difficult to confirm. We did add some options from group C to our filters since they are the only forms known to occur in the area (and I got tired of seeing "Turkey Vulture (Northern)" on the rare bird alerts).

We also *removed* some taxa that are supposed to be on the filters, such as the Short-billed Dowitcher subspecies groups. These are very difficult to identify during fall migration and the eBird reviewers decided that a photo would be necessary to validate this species to subspecies level due to the challenging ID. Filters are dynamic and change all the time. I'm considering re-adding the dowitcher subspecies in spring only when they are more field-identifiable.

The full list of eBird forms/subspecies is available to the public here:

https://help.ebird.org/customer/en/portal/articles/1822748-ebird-review-standards

Scroll down to Filter_taxa_recommendations_19Jan2016_USA_and_Canada.xlsx

The key point (bold, italics, underline) is that anything NOT on our filters will go out to the rarity alerts, even if it isn't rare. This is why you're seeing Canada Goose (canadensis) on the rarity alerts. We are not putting this on the filter per eBird guidance (emphasis added):

Important note: Introduced, urban-breeding Canada Geese (including all those breeding in Lower 48 states) are an introgressed swarm that should not be identified to subspecies (moffitti, maxima, and canadensis stock has been used, at least). These birds should be reported simply as Canada Goose. Because of the ID issues with all Canada Goose subspecies (Dusky probably most distinctive), we recommend NOT including Canada Goose subspecies. Some observers may report them, and we generally encourage photos to establish that the subspecies are being used properly (and introduced populations not being reported at the subspecies level). Some editors may want to include them, but please do so with extreme caution and encourage documented records as much as possible.

We recently added many of the subspecies/forms to the filters to prevent them from going out on the rarity alerts but we are not comfortable adding Canada Goose (canadensis). Still, some observers insist on adding everything to subspecies level which is a bit of a gray area in eBird and will likely go through multiple reviews over time as we learn more about bird distribution. These cannot be validated in eBird based on the information presented above.

Tim Carney

Parkville, MD

[Scott Young]

Thanks all. 

So basically, if I understand correctly, the answer to my first question is yes, pictures should be included. 

However, as far as my second question goes, as I dig into this species, there are, as defined by genetic analyses, 7 large subspecies, most likely, and 4 smaller ones (too many commas?). Size and color variation are extensive overlapping and genetic analysis would be needed to be sure of the ID. So, really no way to describe from the field for sure, even with pictures, the subspecies...

Please direct me to a good description of field marks with pictures and correlated genetic analysis if I am incorrect!

Thanks again.

Scott Young

Gaithersburg, MD

[Steve Long]

Quite a while ago, there was a group of migratory Canada Geese, that
visited what is now my yard.  They were distinctly bigger than the rest
of the Canadas, and they each had a white spot on their forehead.  The
were here at least 2 sequential winters, and came quite close to the
house.  My mother referred to them as the "Giant Race" of Canada Goose,
which she seemed to have picked-up from one of her bird books at that time.

Can anybody tell me what the subspecies would be for those geese?

Steve Long, Oxford

[JAMES SPEICHER]

On Tue, Aug 6, 2019 at 2:59 PM Tim Carney <timm...@gmail.com> wrote:

Extremely long response I drafted with input from Matt Hafner and Tyler Bell:

A nice feature for compilers who receive SHARED checklists that may have subspecies/forms included is that the summarized data seems to revert everything back to the common species.  That allowed me to keep more of my diminishing supply of hair when I was compiling the C&O count this year...

Jim Speicher
BroadRun/Burkittsville area
[FR] Frederick County
WA Co. MOS member
C&O count coordinator