Your name Aaron Beerman Email [email protected] Bird identification Tundra Bean-goose Date(s) April 19, 2019 Time of Day 5:40 pm Location Pasture adjacent to Crooked River Wetlands, Prineville, OR Lighting and Weather Conditions Partly cloudy Details Description of Bird: (This bird was widely reported and many photos are accessible on eBird and elsewhere so I will not detail the bird’s appearance too extensively but instead focus on key features important for comparison to the relevant subspecies of Bean-goose). These are some things that we observed. The bird appeared slightly smaller in proportion from the nearby Canada Geese (Moffitti). At most angles of view this bird’s head appeared rounded (although, to my eyes somewhat more oval than the two previous documented Oregon Tundra Bean-geese). Its bill was relatively long, thick based, and the culmen mostly straight and lacking a significant curve. The gape noticeably broad and deep set. The bill color was black with yellowish-orange band which covered a little less than 1/3 of the bill length. After review of several photos the bill nail appeared oval shape when facing straight on rather than concave on top and bottom. In my perspective the neck of the bird appeared consistently short and stocky during the length of our observation, as well as in review of images taken on later dates by others. Although hard to estimate, the legs also appeared orange in color and average length, not long. No vocalization was noted during our observations. Similar Species Taiga Bean-goose middendorffii subspecies is really the only other comparable species, in terms of appearance and geographic range. Although the separation of these two species can be at times be challenging, there are several important feature of the Prineville bird that I believe point away from middendorffii. From what I have read, the Taiga Bean-goose is broadly characterized by its long swan- like neck, elongated bill, flat fore-crown and generally taller, prominent appearance. Most subspecies exhibit a wide yellow bill band and less pronounce lower mandible. Crucially, it is has been said by other more experienced with these subspecies that the overall jizz of the bill, neck and body structure are the essential features for distinguishing the Tundra and Taiga species. i.e. it’s easy to over analysis characteristics such as the bill long or extend of bill band coloration. In the case of the Prineville goose, as previously noted, it appeared necked, and short legged, not exhibiting obvious swan-like features. The bills in-set gape, thick based I think better fit Tundra Bean-goose over Taigi. From: Charles Gates <[email protected]> Subject: Tundra Bean Goose Date: April 19, 2019 at 10:27:19 PM PDT To: Treesa Hertzel <[email protected]> Here are two photos for my Rare Bird Report to the Records Committee. Tundra Bean-Goose in Crook County. -- It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so. Mark Twain Chuck Gates Prineville Bird Club 541-280-4957 Powell Butte, Central Oregon Oregon Birding Site Guide http://www.ecaudubon.org/birding-locations Oregon County Checklists http://www.ecaudubon.org/county-checklists --- This email has been checked for viruses by AVG. https://www.avg.com TUBG-2019-03 (Tundra Bean Goose) 1st Round Vote — July 28, 2019 Accepted, verified: 6 Species Unresolved: 3 ACCEPTED, VERIFIED Could we obtain some of the other photos for our file? or at least links? I observed and photographed this bird as well, and can provide a description if needed. However, I believe the photos and descriptions are sufficient to identify this bird as a Tundra Bean Goose. Good photos, and Aaron offers a good analysis comparing this bird with middendorffi Taiga Bean-Goose. I concur with his reasoning and believe this bird is a Tundra Bean-Goose. Nice write up and photos. Another high profile rarity that was seen by many, and yet a fraction of the photos have been submitted to the committee. In terms of the identity of this goose, I am in agreement with this being a Tundra Bean Goose, likely of the subspecies “serrirostris”. The head proportions and especially the bill seem a little elongated for a “serrirostris” Tundra Bean-Goose, especially when compared with the Finley Tundra from last Fall/Winter, but still within range. This bird doesn’t appear to have as long as a neck I’d expect on a typical “middendorffii” Taiga Bean-Goose, a subspecies of the most similarly looking species one must eliminate. The grin patch, from what we can see, appears rather wide, ovular, and deeply recessed. This last feature, a deeply set grin patch, seems to slightly favor “serrirostris” over “middendorffii” in my opinion. Another factor in favor of “serrirostris” is the overall amount of yellowish coloration on the bill and it’s position closer to the middle of the bill. According to my research, a “middendorffii” should have a more restricted yellowish patch, farther away from the middle of the bill. As to the overall size of this bird, according to Sebastian Reeber’s Waterfowl of Europe, North America, and Asia, “There is a relatively strong variation in mass during the annual cycle,...being lighter in Jan and heavier in Mar-Apr, before northward departure”. I also read that there is some slight overlap in size between the two.The shape of this bird’s head isn’t as flat as I’d expect on a “middendorffii” and seems better for a “serrirostris”. Also, the coloration is somewhat dark, showing an almost capped appearance, which during my research for the Finley bird, I found pretty consistently on Tundra Bean-Geese and not so much on Taigas. Not sure how reliable of a fieldmark this is, but anecdotally, it seemed to hold up decently well. I was slightly concerned back in the spring as to how long this bird remained. It was documented in the area for 15 days. This does seem a little on the long side for a seemingly wild goose to linger during spring migration, but not unheard of. The window that this bird was seen, April 19th through May 3rd, does seem consistent with the broader trends of migration of Canada Geese/Cackling Geese through our state. In some reports on eBird, this bird was mentioned to possibly be injured or unwell, sometimes walking with a slight limp, potentially factoring into why it lingered as long as it did. In the past two years in this general area, there have been observations of both Hawaiian Goose and Smew, which were later found to originate from a local resident and breeder with an exotic waterfowl collection. Apparently Chuck Gates reached out to this person and confirmed that the Tundra Bean Goose was not a part of her collection. See this checklist for the comment: (https://ebird.org/view/checklist/S55164287). One final note in regard to provenance, in some photos on eBird, this bird can be seen to have its hind toes intact, strengthening the case that it was in fact a wild bird. No comments There are additional photos of this bird on eBird at https://ebird.org/species/tunbeg1/US-OR-013. This bird has characteristics typical of the subspecies serrirostris. The bird has a relatively short neck, a relatively dark head, a broad deep gape, a relatively thick bill, and an orange band near the tip of the bill, all of which are consistent with the subspecies serrirostris. SPECIES UNRESOLVED I think this is a Tundra Bean Goose, but due to the complexity of the ID, discussion and a second round of voting would be warranted. This bird seems on par for Oregon's previous two records of Bean Goose, which have been labeled as Tundra. In particular, the bill is fairly short with a deep base and only a little bit of orange. The neck seems short. I appreciate Aaron's careful analysis of why he thinks this is a serrirostris (i.e, Tundra Bean Goose) and not a middendorffii (eastern subspecies of Taiga B G). However, I'm wondering if we haven't been too glib about the recent Bean Geese in Oregon. Back when they were all "Bean Geese", the wisdom was to avoid trying to identify to the subspecies level "except by locality of observation" (Madge & Burn). Of course, once they were split everyone was motivated to determine a species. It's not clear to me that there have been subsequent advances in identification that now justify being certain which former subspecies we're looking at. I agree that this is a Bean Goose, but I'm not 100% convinced that the photos and description sufficiently eliminate the possibility that this is a middendorffi Taiga Bean Goose. The forehead profile seems quite flat in one photo and the bird appears long-necked in one photo and short-necked in the other. The bill seems to be somewhat in between middendorffi and serrirostris in shape and length in the photos, at least as shown in Reeber. Reeber also notes that some birds originating in East Asia can appear intermediate between the two with some overlap in overall size. I'm leaning towards agreement with the reporter, but feel there is enough uncertainty to take this to the second round. I also wonder about provenance with the recent cluster of exotic waterfowl that have appeared in the area, including Nene, Smew, and Emperor Goose. The timing of this bird is also a little odd with most (or all?) other records of Bean Geese showing up in the western U.S.