Boyd Lake Gulls (7 species + 2?), Larimer Co.

[Doug Ward]

Pulled into Boyd Lake State Park (Larimer Co.,CO) late this afternoon (22 Feb.'20), around 3:30pm, to walk the dogs as we noticed a fair amount of waterfowl on the open water, but of interest to me as a confirmed gull nerd, were the good numbers of gulls coming in from the direction of the Larimer County Landfill to roost.  After a quick walk of the dogs, I pulled the scope out and started through the flock.  As usual, most of the +/-250 gulls were adult RING-BILLEDs, then came across an adult CALIFORNIA, a couple of 1st year HERRINGS, then a nice adult LESSER BLACK-BACKED...now it's getting interesting.  Just about the time I moved on from the Lesser Black-backed a huge 1st year GREAT BLACK-BACKED GULL came flying in and landed on the water amongst some now puny Ring-billeds.  Continuing on picked out a nice 1st year Thayer's...I mean "Thayer's" ICELAND, then another nearby.  After another pass noticed a large, pale gull harassing some mergansers.  A clear 1st year GLAUCOUS-WINGED GULL!  This guy (or gal) was slightly larger than a nearby Herring, entirely even pale muddy grayish tan with entirely light tan, translucent primaries, and the all black droopy bill of this species; best one of the day!  Maybe more interesting, however, were two (2) unidentifiable gulls which if you had a gun to my head would probably call Glaucous-winged X Herrings, a 1st year and a 2nd year.  The 1st year bird was very similar to a likely Glaucous-winged X Herring I saw a few weeks ago in Vancouver, BC.  Tacked on a couple more Lesser Black-backed and a 2nd year Thayer's to really make a good day for me out there.

Primary purpose of the post was to alert anyone who might be in the area to check Boyd Lake in the afternoon to satiate your inner gull nerd.  Based on the mix here today, guessing some of these guys were part of the flock found a few weeks back at Warren Lake.  Good luck if you head out.

Good Gulling,

Doug

Denver

22 February 2020  Boyd Lake State Park, Larimer Co., CO

Canada Goose – 25

Northern Shoveler – 10

American Widgeon – 10

Mallard – 30

Canvasback – 8

Redhead – 120

Ring-necked Duck – 30

Lesser Scaup – 3

Common Goldeneye – 2

Hooded Merganser – 14

Common Merganser – 45

Red-breasted Merganser – 2m

Rock Pigeon – 6

American Coot – 20

Ring-billed Gull – 200ad, 20-1^st

California Gull – 4ad

Herring Gull – 10ad, 1-3^rd, 3-2nd, 6-1^st

ICELAND GULL “Thayer’s” – 1-2^nd, 2-1^st

LESSER BLACK-BACKED GULL – 3ad, 1-3^rd, 1-1^st

GLAUCOUS-WINGED GULL – 1-1^st

GREAT BLACK-BACKED GULL – 1-1^st

gull sp. – 1-2^nd, 1-1^st (both likely GWGU X HEGU)

Bald Eagle – 1ad, 1 imm

Red-tailed Hawk – 2

European Starling – 5

American Tree Sparrow – 2

Song Sparrow - 1