Hi All To add to Nick’s comments, it’s also a hell of a lot of fun! Glenn and I had a blast yesterday sorting through the mess that is gulls in Colorado. Thanks, Nick, for getting the word out on these critters. Steve Larson Northglenn CO
Sent from my iPhone > On Feb 1, 2020, at 11:19 PM, Nicholas Komar <[email protected]> wrote: > > COMMENTS ON WARREN LAKE GULLS (long): > > 1. I couldn’t visit Warren Lake today, but according to reports on eBird, the > show continues. For anyone interested in practicing and improving gull ID > skills, this is a great opportunity. > > 2. Many of the gulls at Warren Lake are large brown immature, mostly first > year gulls. These can be quite variable and plumage patterns vary across > species, with some plumages overlapping, making species ID difficult. The > situation is further complicated by hybridization. > > 3. Herring Gull hybrids are particularly confusing. At least 5 different > hybrid combinations of Herring with different Gull species have occurred in > Larimer County. Right now at Warren, presumed Herring x Glaucous (“Nelson’s > Gull”) and Herring x Glaucous-winged (“Cook Inlet Gull”) hybrids are being > reported. There may indeed be multiple Cook Inlet Gulls. > > 4. One large pale uniformly pale brown gull resembles Glaucous-winged Gull. > Some west coast experts have reviewed low quality photos and have suggested > some genetic influence from Herring Gull. I suspect that it might be a > genetic backcross, one or (likely) more generations removed from the > hybridization event. Whether you count this bird on your list (or in eBird) > as Glaucous-winged Gull or as Cook Inlet is a personal decision. My guess is > that the eBird reviewer will leave this rarity as unconfirmed until the > Colorado Bird Records Committee judges the submitted rare bird reports and > accompanying photo and video documentation. > > 5. Several of these confusing gulls resemble first year Slaty-backed Gull > (SBGU) which has only been documented in Colorado a few times, as adults. One > in particular presents all the classic traits of SBGU as depicted in “gulls > of North America, Europe and Asia” by KM Olsen and H Larson. I posted photos > to eBird on 1/29/20 after receiving input from an expert that “it looks > promising” for SBGU. Another expert was less supportive and suggested Herring > or Cook Inlet as possible ID. In the description on eBird I wrote > “tentatively identified” pending further review. After posting it on North > American Gulls Facebook page, I received luke warm support for SBGU (roughly > 50% of informed opinions have supported SBGU). Part of the problem is that > published gull identification textbooks (e.g. Gulls of the America’s by > Howell and Dunn) claim that some young Cook Inlet gulls can look like the > classic SBGU. Therefore, technically according to these experts, this plumage > of SBGU is unidentifiable with certainty. Thus, again, counting this bird on > your list or in eBird is a personal decision. I chose to report it to eBird > as a way of spreading the word of a possible SBGU (through the eBird alert > system). I don’t expect it to be confirmed in eBird. However it is a bird > that merits further study and better documentation. Had I reported it as > Larus sp or gull sp, it would have been largely ignored by the birding > community. > > 6. Today, Glenn Walbek obtained much better quality photos of what appears to > be the same bird. His assessment was the same as mine. I encourage you to > read his description and see his high quality photos in eBird. > > 7. We may never know with 100% certainty what is this bird’s true identity > (unless we get a DNA sample, or we manage to track it for several years > through its molts to adult plumage). > > 8. Regarding the suggestion that I may have mistakenly identified this bird, > I reiterate that I do not know with 100% confidence what it is. I can say > (with 100% confidence) that it LOOKS LIKE Slaty-backed Gull. > > 9. Regarding the suggestion that I have erroneously identified birds in past > years, I don’t recall ever making a mistake ;-). However everyone makes > mistakes, even the experts. > > 10. The gulls at Warren Lake may not all be identifiable, but they definitely > offer a great learning opportunity for birders who want to learn more about > gull identification. > > Nick Komar > Fort Collins CO > >> On Feb 1, 2020, at 6:38 PM, 'Azz85' via Colorado Birds >> <[email protected]> wrote: >> >> Steve hasn’t chimed in for the gulls because he is in Baja Mexico. >> >> Sent from my iPhone >> >>> On Feb 1, 2020, at 6:33 PM, John D <[email protected]> wrote: >>> >>> >>> Aaron : >>> >>> I have not heard of any confirmation from outside of CO gull experts to >>> confirm either , but the Glaucous-winged looks more likely to me , I am >>> very uncertain about the Slaty-backed .Nick Komar has been wrong in >>> previous years . >>> >>> Any way I will be traveling up with Lynne Miller tomorrow to check the >>> gulls out , not that I need either for my state list but Lynne needs >>> Slaty-backed .I think we will arrive around 10:30 .Perhaps we will see you >>> there . >>> >>> Best >>> >>> John >>> >>> >>> -----Original Message----- >>> From: 'Azz85' via Colorado Birds <[email protected]> >>> To: quetzal65 <[email protected]> >>> Cc: Cobirds <[email protected]> >>> Sent: Sat, Feb 1, 2020 4:59 pm >>> Subject: Re: [cobirds] Warren Lake gulls (Larimer) >>> >>> I am interested in chasing the gulls at Warren lake. It is a bit of a >>> drive, so I am wondering if anyone is 100% confident with the slaty-backed >>> and glaucous-winged identification? >>> >>> I have noticed that some people are calling the bird good and some hybrids. >>> Are these pure gulls? >>> >>> I’ll defer to the experts >>> >>> Any help would be appreciated. >>> >>> Thanks >>> Aaron Shipe >>> Jeffco >>> >>> Sent from my iPhone >>> >>> > On Jan 29, 2020, at 10:54 PM, Nicholas Komar <[email protected]> >>> > wrote: >>> > >>> > Warren Lake is currently a gull hotspot, due to large fish population >>> > with a large flock of common mergansers and common Goldeneye bringing >>> > fish to the surface. Furthermore, there seems to be many dead fish frozen >>> > in the ice sheet at the west end. The smorgasbord is attracting 500-600 >>> > gulls present throughout the day. The area is private. However birders >>> > are welcome at the lake. Just use common sense. Stay off residential >>> > properties. >>> > >>> > Gull numbers are as follows: >>> > Ring-billed Gull - 500 (99% adult) >>> > Herring Gull - 20 (40% adult) >>> > Iceland (Thayer’s) Gull - 10-15 (10% adult) >>> > Lesser Black-backed Gull- 6-10 (40% adult) >>> > Glaucous Gull -1 immature >>> > Great Black-backed Gull-1 immature >>> > Mystery gulls-10 or so. >>> > >>> > The mystery gulls are mostly immature gulls that are >>> > somewhat atypical. Most of these are probably Herring Gull hybrids such >>> > as “Nelson’s” Gull (with Glaucous) and “Cook Inlet” Gull (with >>> > Glaucous-winged). Today there were two first-Year large gulls that >>> > resembled Glaucous-winged and one that resembled Slaty-backed. Better >>> > photos are needed to confirm these. >>> > >>> > Nick Komar >>> > Fort Collins CO >>> > >>> > -- >>> > You received this message because you are subscribed to the Google Groups >>> > "Colorado Birds" group. >>> > To unsubscribe from this group and stop receiving emails from it, send an >>> > email to [email protected]. >>> > To view this discussion on the web visit >>> > https://groups.google.com/d/msgid/cobirds/00F51F3E-FFA5-4FED-AC9E-EFB122B1116D%40comcast.net. >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Colorado Birds" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/cobirds/A99702F8-5091-4D4F-91F1-FE7B6ADC5E19%40aol.com. >> -- >> You received this message because you are subscribed to the Google Groups >> "Colorado Birds" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/cobirds/A8100287-8A0E-4183-9EF7-B2CF851C5C47%40aol.com. > -- > You received this message because you are subscribed to the Google Groups > "Colorado Birds" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/cobirds/B0E94840-55DA-4D13-A053-206F5D48FF6E%40comcast.net. -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/7E0CE120-1F1C-4093-86A7-81AD37CDD133%40comcast.net.
