Documenting hybrid geese in Colorado for eBird (& a few other matters)
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Ted Floyd
Feb 1, 2025, 11:30:16 PMFeb 1
to Colorado Birds
Hey, everybody.
Colorado eBirders have been doing a great job in recent winters of reporting hybrid geese. Ranges are expanding and numbers are increasing for several species of geese that breed in the Arctic and winter to Colorado, and it is not surprising that we are seeing more hybrids than in the past.
Some hybrid combos, like Greater White-fronted Goose x Canada Goose, are rather stereotyped and can probably be reliably identified in the field. Trickier for us in Colorado are hybrid geese with one Snow/Ross's parent and one Cackling/Canada parent. Here's the deal. For a hybrid Snow/Ross's x Cackling/Canada not supported by a photo, please eBird it as just that: Snow/Ross's x Cackling/Canada. With photos, however, it may be possible to determine the precise hybrid combo—for example, Snow x Cackling, which seems in Colorado to be the most common of the four possibilities. And identifications at that level of precision require a photo (or, better, a series of photos) for inclusion in the public database.
I had an experience earlier today, Sat., Feb. 1, at Stearns Lake, Boulder Co., that illustrates how the hybrid goose review process works. First off, here's the eBird checklist, with the hybrid goose being the third entry on the checklist:
https://ebird.org/checklist/S211590233
I have provisionally identified the bird as a Snow x Canada hybrid. It is up to an eBird reviewer (other than Yours Truly) to evaluate the record. In particularly tricky cases, experts from outside Colorado may be appealed to; but, honestly, in the case of hybrid geese, eBird reviewers in Colorado probably have as good a handle on the matter as experts anywhere. Not that I would ever be guilty of Colorado homerism or anything like that... If the record is not accepted as a Snow x Canada hybrid, then I will change it to the more inclusive Snow/Ross's x Cackling/Canada combo—ensuring that the photos and the occurrence remain in the public database.
Bottom line:
Snow/Ross's x Cackling/Canada without photos—that's fine, but provide a written description.
Snow x Cackling, Snow x Canada, etc.—photo(s) required.
Photos and audio are absolutely the gold standard for eBird documentation, but I want to take this opportunity to exhort folks to provide written descriptions where photos are not possible. Indeed, that happened to me this afternoon. I was running an errand in Louisville, Boulder Co., and I saw a Gray Catbird, an eBird review species for the winter months in Boulder Co. Here's the checklist:
https://ebird.org/checklist/S211595377
The Gray Catbird is toward the bottom of the checklist. I haven't checked the eBird review queue yet, but I imagine that one will sail through the review process. It's not a hard ID; I saw the bird well; it's honestly not all that rare here in winter; and, most important, I provided a written description for the reviewer to evaluate.
One other thought, whilst I'm in a verbose mood this Candlemas eve. And happy happy to all who observe. Imolc, too, and Marmot Day. Lots going on. But I digress. Back to eBird. While we're busy photo-documenting hybrid geese and writing down descriptions of catbirds, let's also consider the supreme value of taking a bit of time to explain high counts on eBird checklists. Consider again my Stearns Lake checklist from today:
https://ebird.org/checklist/S211590233
First, bop on down to American Tree Sparrow. A decent flock of at least 76 individuals. How do I know that?—I actually counted them up in my photos. See details on checklist for methods.
Then, at the bottom, see Western Meadowlark. Another high count, this time of 70 individuals. A photo wasn't possible, as they were mostly popping out of a corn field in singles and pairs, but I did count most of them, and conservatively estimated the rest of the birds I saw and heard out there. And the main point: I wrote it down.
Alrighty, that's what I got tonight. Take pics of hybrid geese; photo-document high counts where possible; and we can never put too many notes in our eBird checklists!
Ted Floyd
Lafayette, Boulder Co.
Some hybrid combos, like Greater White-fronted Goose x Canada Goose, are rather stereotyped and can probably be reliably identified in the field. Trickier for us in Colorado are hybrid geese with one Snow/Ross's parent and one Cackling/Canada parent. Here's the deal. For a hybrid Snow/Ross's x Cackling/Canada not supported by a photo, please eBird it as just that: Snow/Ross's x Cackling/Canada. With photos, however, it may be possible to determine the precise hybrid combo—for example, Snow x Cackling, which seems in Colorado to be the most common of the four possibilities. And identifications at that level of precision require a photo (or, better, a series of photos) for inclusion in the public database.
I had an experience earlier today, Sat., Feb. 1, at Stearns Lake, Boulder Co., that illustrates how the hybrid goose review process works. First off, here's the eBird checklist, with the hybrid goose being the third entry on the checklist:
https://ebird.org/checklist/S211590233
I have provisionally identified the bird as a Snow x Canada hybrid. It is up to an eBird reviewer (other than Yours Truly) to evaluate the record. In particularly tricky cases, experts from outside Colorado may be appealed to; but, honestly, in the case of hybrid geese, eBird reviewers in Colorado probably have as good a handle on the matter as experts anywhere. Not that I would ever be guilty of Colorado homerism or anything like that... If the record is not accepted as a Snow x Canada hybrid, then I will change it to the more inclusive Snow/Ross's x Cackling/Canada combo—ensuring that the photos and the occurrence remain in the public database.
Bottom line:
Snow/Ross's x Cackling/Canada without photos—that's fine, but provide a written description.
Snow x Cackling, Snow x Canada, etc.—photo(s) required.
Photos and audio are absolutely the gold standard for eBird documentation, but I want to take this opportunity to exhort folks to provide written descriptions where photos are not possible. Indeed, that happened to me this afternoon. I was running an errand in Louisville, Boulder Co., and I saw a Gray Catbird, an eBird review species for the winter months in Boulder Co. Here's the checklist:
https://ebird.org/checklist/S211595377
The Gray Catbird is toward the bottom of the checklist. I haven't checked the eBird review queue yet, but I imagine that one will sail through the review process. It's not a hard ID; I saw the bird well; it's honestly not all that rare here in winter; and, most important, I provided a written description for the reviewer to evaluate.
One other thought, whilst I'm in a verbose mood this Candlemas eve. And happy happy to all who observe. Imolc, too, and Marmot Day. Lots going on. But I digress. Back to eBird. While we're busy photo-documenting hybrid geese and writing down descriptions of catbirds, let's also consider the supreme value of taking a bit of time to explain high counts on eBird checklists. Consider again my Stearns Lake checklist from today:
https://ebird.org/checklist/S211590233
First, bop on down to American Tree Sparrow. A decent flock of at least 76 individuals. How do I know that?—I actually counted them up in my photos. See details on checklist for methods.
Then, at the bottom, see Western Meadowlark. Another high count, this time of 70 individuals. A photo wasn't possible, as they were mostly popping out of a corn field in singles and pairs, but I did count most of them, and conservatively estimated the rest of the birds I saw and heard out there. And the main point: I wrote it down.
Alrighty, that's what I got tonight. Take pics of hybrid geese; photo-document high counts where possible; and we can never put too many notes in our eBird checklists!
Ted Floyd
Lafayette, Boulder Co.
l p
Feb 7, 2025, 9:36:42 AMFeb 7
to Colorado Birds
Hi Ted, what about a provisional ID on an Hybrid Duck? with a photo? I posted what might be a gadwall x northern pintail hybrid to this site yesterday. i'm reluctant to get this wrong on ebird, but I would certainly like to get it on ebird as a correct hybrid species, if that is the case.
i changed the ID on my checklist from hybrid to simply gadwall with an explanation.
thank you
Linda Purcell
l p
Feb 15, 2025, 8:27:51 PMFeb 15
to Colorado Birds
sorry for any confusion. this was Centennial Park, 6 Feb 2025.
Jake Shorty
Dec 7, 2025, 1:57:13 PM (yesterday) Dec 7
to Colorado Birds
Hi all, it's that time of year again and I wanted to bump Ted's guidelines for reporting goose hybrids on eBird:
Some hybrid combos, like Greater White-fronted Goose x Canada Goose, are rather stereotyped and can probably be reliably identified in the field. Trickier for us in Colorado are hybrid geese with one Snow/Ross's parent and one Cackling/Canada parent. Here's the deal. For a hybrid Snow/Ross's x Cackling/Canada not supported by a photo, please eBird it as just that: Snow/Ross's x Cackling/Canada. With photos, however, it may be possible to determine the precise hybrid combo—for example, Snow x Cackling, which seems in Colorado to be the most common of the four possibilities. And identifications at that level of precision require a photo (or, better, a series of photos) for inclusion in the public database.
Hybrids (and goose subspecies) require careful review, and even with photos things can remain uncertain. It's not a ding against one's expertise to use slash designations and conservative taxa as a default! It provides more scientifically rigorous data for all the bird populations involved.
Best,
Jake Shorty
Denver
Some hybrid combos, like Greater White-fronted Goose x Canada Goose, are rather stereotyped and can probably be reliably identified in the field. Trickier for us in Colorado are hybrid geese with one Snow/Ross's parent and one Cackling/Canada parent. Here's the deal. For a hybrid Snow/Ross's x Cackling/Canada not supported by a photo, please eBird it as just that: Snow/Ross's x Cackling/Canada. With photos, however, it may be possible to determine the precise hybrid combo—for example, Snow x Cackling, which seems in Colorado to be the most common of the four possibilities. And identifications at that level of precision require a photo (or, better, a series of photos) for inclusion in the public database.
Hybrids (and goose subspecies) require careful review, and even with photos things can remain uncertain. It's not a ding against one's expertise to use slash designations and conservative taxa as a default! It provides more scientifically rigorous data for all the bird populations involved.
Best,
Jake Shorty
Denver
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