Sightings:
- Heermann's Gull (1st cycle). Kitsap County, Washington. 01 January 2021.
- Laughing Gull (1st cycle). Seneca County, New York. 01 January 2021.
- Great Black-backed Gull (1st cycle). Charles Mix County, South Dakota. 01 January 2021.
- California Gull (adult). Chambers County, Texas. 02 January 2021.
- Mew Gull (1st cycle). Taylor County, Texas. 03 January 2021.
- Laughing Gull (1st cycle). Pope/Yell County, Arkansas. 03 January 2021.
- California Gull (adult). New Haven County, Connecticut. 03 January 2021.
- 3rd State Record.
- California Gull (adult). Sangamon County, Illinois. 03 January 2021.
- Taimyr Gull (adult). Pictou County, Nova Scotia. 04 January 2021.
- Presumed taimyrensis*. Unprecedented. Would be the 1st for the Atlantic.
- Black-headed Gull (2 adults). Cuyahoga County, Ohio. 04 January 2021.
- Black-legged Kittiwake (1st cycle). Monroe County, New York. 05 January 2021.
- Slaty-backed Gull (adult). Niagara County, Ontario. 07 January 2021.
- Franklin's Gull (adult). Hughes County, South Dakota. 07 January 2021.
- Ivory Gull (6 adults). Nome County, Alaska. 07 January 2021.
- Little Gull (adult). Lake County, Tennessee. 08 January 2021.
- Great Black-backed Gull (1st cycle). Boulder County, Colorado. 09 January 2021.
- Franklin's Gull (1st cycle). Del Norte County, California. 12 January 2021.
- California Gull (1st cycle). East Baton Rouge Parish, Louisiana. 12 January 2021.
- Laughing Gull (1st cycle). Cuyahoga County, Ohio. 14 January 2021.
- Slaty-backed Gull (1st cycle). San Mateo County, California. 15 January 2021.
- Laughing Gull (1st cycle). Ozaukee County, Wisconsin. 16 January 2021.
- Ross's Gull (2nd cycle type). New Haven County, Connecticut. 16 January 2021.
- California Gull (2nd cycle). Lee County, Iowa. 18 January 2021.
- Slaty-backed Gull (adult). Simcoe County, Ontario. 18 January 2021.
- Slaty-backed Gull (adult). Niagara County, New York. 19 January 2021.
- Black-headed Gull (adult). Erie County, Pennsylvania. 22 January 2021.
- Western Gull (adult). Davis County, Utah. 23 January 2021.
- Little Gull (2nd cycle). Panola County, Mississippi. 23 January 2021.
- Great Black-backed Gull (1st cycle). Clay County, Missouri. 24 January 2021.
- Great Black-backed Gull (1st cycle). Douglas County, Kansas. 24 January 2021.
- Heermann's Gull (2nd cycle). Volusia County, Florida. 24 January 2021.
- Presumably same individual since August 2019.
- Black-legged Kittiwake (1st cycle). Tazwell County, Illinois. 24 January 2021.
- Slaty-backed Gull (adult). Marin County, California. 24 January 2021.
- Slaty-backed Gull (adult). Benton County, Washington. 26 January 2021.
- California Gull (adult). Lorain County, Ohio. 27 January 2021.
- Common Gull (1st cycle). Kings County, New York. 28 January 2021.
- Ross's Gull (1st cycle). Lincoln County, Oregon. 30 January 2021.
- 3rd State Record.
- Mew Gull (2 adults). Hughes County, South Dakota. 31 January 2021.
Notes:
1. Angela MacDonald found an adult type taimyrensis in New Glasgow, Nova Scotia on 04 January 2021. A darkish eye, fine streaking restricted to the lower hindneck and a sherbert-orange/yellow leg color support this taxon. Late primary molt is also in favor of this Asian form. P1-P7 new and fully grown, P8 80% grown, P9-P10 retained. P10 with medium to large mirror, P9 with small rounded mirror not reaching the outer web. Black on P7/P8 reaching p-coverts along the outer webs. Full, asymmetric subterminal band on P4, and black mark on outer web of P3 (on right wing). No white tongue tips on P6-P7, with very little slivers of white on inner webs of P4-P5. The taxonomy on Taimyr Gull is unsettled. Some authorities treat it as a hybrid population between Heuglin's and Vega Gull, others place it with the Lesser Black-backed Gulls. A recently adopted position on this form is that it is a good taxon worthy of species rank.