Status of the Mew Gull Complex in Massachusetts: Special 28th Report of the Massachusetts Avian Records Committee (MARC)

Marshall J. Iliff

October 1, 2025 17 MIN READ Bird Sightings, Feature Articles

Mew Gull split in 2021

In 2021, the American Ornithological Society (AOS) accepted a proposal (Rasmussen 2020) to split the Mew Gull (Larus canus) complex into two species: Short-billed Gull (Larus brachyrhynchus), of western North America, and Common Gull (Larus canus), of the Palearctic. The four taxa in the complex now break down as follows:

• Larus canus canus breeds in northwestern Europe and has long been known as a rare vagrant to Atlantic Canada and the northeastern United States.
• Larus canus heinei breeds from northeastern Europe to central Russia and winters in the Caspian and Black Sea area; it is a rare stray to western Europe and yet unconfirmed from the Americas.
• Larus canus kamtschatschensis (Kamchatka Gull) breeds in eastern Russia and winters in east Asia, south to southern China, and exceptionally to the Gulf of Thailand. It is a rare but regular stray to western Alaska, including the Aleutian and Pribilof archipelagos, St. Lawrence Island (especially Gambell), and on extremely rare occasions, the Alaskan mainland, Canada, and the Lower 48 states.
• Larus brachyrhynchus (Short-billed Gull) breeds in Alaska and northwestern Canada and winters along the Pacific Coast south to northern Baja California; it is a casual stray to interior United States and Canada and a rare to accidental vagrant to the eastern United States, exceptionally to the Azores.

Identification of the four taxa is extremely difficult, may not be possible in some plumages, and is often not possible without excellent views in flight. It depends on assessing the size, structure, and mantle shade relative to Ring-billed Gull, the width of the white tips to the inner primaries (broader in L. brachyrhynchus), the bill color and pattern, the extent and pattern of head streaking, and, most important, the exact wingtip pattern for the outer primaries. See Sibley (2021) for an illustrated overview of field identification. For a deep dive, see Adriaens and Gibbins (2016), which extensively documents the full range of variation across all four taxa, redefining field identification of these taxa for the past decade.

Good spread-wing or in-flight photos are almost required for acceptance of any record to species or subspecies. They made possible the detailed same-bird analyses discussed in this report. We encourage anyone lucky enough to find a potential vagrant Mew Gull to prioritize getting spread-wing images.

The great MARC Mew review

When the Mew Gull complex split took effect, the MARC database had only partial information on the occurrence rates of each taxon and on the true number of records for each. The MARC decided to review the original documentation for all state records for the Mew Gull complex before the split occurred, and also to undertake a new review of all the new records. I embarked on that mission in the summer of 2021. This article reports on the MARC decisions, clarifies the status of each taxon, and discusses the difficult assessments of same-bird issues and other revelations.

Of the records mentioned in Veit and Petersen (1993), only the 1908 specimen has been reviewed, with the first brachyrhynchus report currently under review; other reports mentioned therein have not been reviewed due to lack of extant documentation. Except for one in 1999, no Mew Gull sightings were reviewed from observation dates between 1993 and 2003. Although a handful of records were reviewed between 2003 and 2021, members did not consistently consider subspecies and MARC reports did not consistently report subspecies, even when known. The complicated question of returning individuals was rarely considered. Though it can be difficult to assess when records pertain to a same or different individual, that helps to understand the rates of vagrancy for a species and the movements, habits, and length of stay for individual vagrants; it also is important for basic statistics on the number of state records for a species.

Starting in 2021, the MARC has proactively tried to collect and review information for all recent records of Short-billed Gull and Common Gull, assess subspecies in all cases, and formally consider which individuals might represent returning birds.

I use Common Gull and Short-billed Gull to refer to the species since the split and use Kamchatka Gull as shorthand for L. c. kamtschatschensis. I refer to the Mew Gull complex for Larus canus/brachyrhynchus when discussing historical status or records that could pertain to any of the four taxa. Because L. c. canus and L. c. heinei do not have widely used, distinctive common names, I refer to those taxa as Larus canus canus and Larus canus heinei.

Status of Common Gull and Short-billed Gull in Massachusetts

The general patterns for subspecies outlined by Veit and Petersen (1993) continue to hold for Massachusetts: L. c. canus as a rare vagrant in winter and spring and L. [c.] brachyrhynchus as exceptionally rare.

All MARC-accepted records appear in this article. For records that needed no revision, you can find the corresponding MARC report at https://maavianrecords.com/annual-reports/. Most revised records—indicated with an asterisk—are summarized in Table 1. An additional four records that were formally revised from kamtschatschensis/heinei to L. c. kamtschatschensis are considered to pertain to Old Reliable. These are 2009-055, 2009-056, 2010-082, and 2011-032; see Common Gull (Kamchatka) section below.

New records—preceded by two asterisks—are reported here for the first time; most were reviewed in 2024. Four records were reviewed in 2025 and are included here for completeness; these are 2024-025, 2025-002, 2013-071, and 1980-005R. When a record or set of records were assigned to a specific individual, that bird was assigned a name and its records are clustered.

Common Gull (European) Larus canus canus

Rare in the state; all records occur along the coast. Sixteen records pertain to at most eight individuals—with six individuals since 2016. All pertain to adults except for one first-winter from Cape Cod in 1908. Dates range from November 24 through April 26, with a strong peak of eight sightings and a stronger peak of five new individuals between March 8 and April 15. One accepted record of Common/Short-billed Gull from May 9 and numerous older records from before 2000 (Veit and Peterson 1993) probably also pertain to this taxon.

1. [1908-004]: first winter, at Pleasant Bay, Chatham, Barnstable, collected 2/2/1908 (16th report).
2. *[2003-002R]: adult, at Cashman Park, Newburyport, Essex, 3/8/2003 to 3/10/2003 [Jim Berry*, Paul Baicich*, Steve Mirick (ph), Erik Neilsen (ph), m.ob.].
3. Whitetip has a distinctive wingtip with almost no black, almost reminiscent of a Kumlien’s Iceland Gull (Larus glaucoides kumlieni). This wing pattern helped distinguish it from another Common Gull (also L. c. canus), Darktip 1, that was present concurrently.
   **[2016-060]: adult, at Race Point, Provincetown, Barnstable, 3/13/2016 to 3/19/2016 [Richard Veit*, K. Charles (ph), m.ob.].
4. Darktip 1: See #3 above. Whitetip was present concurrently at the same location, but this bird was also distinctive.
   **[2016-061]: adult, at Race Point, Provincetown, Barnstable, 3/13/2016 to 3/27/2016 [Marshall Iliff* (ph), Ryan Doherty*, m.ob.].
5. Darktip 2: at Race Point in spring of 2017 and 2018. The details of wing pattern—along with the coincidence of date and location—convinced the committee that all three records pertain to the same individual:
   1. *[2017-005R]: adult, Race Point Beach, Provincetown, Barnstable, 3/26/2017 [Blair Nikula* (ph)].
   2. *[2017-007R]: adult, Race Point Beach, Provincetown, Barnstable, 4/15/2017 [Alan Kneidel*, Nathan Marchessault* (ph)].
   3. *[2018-021R]: adult, Race Point Beach, Provincetown, Barnstable, 4/12/2018 to 4/26/2018 [Maili Waters* (ph), Will Sweet* (ph), Jacob Socolar,* m.ob.].
6. Akila: This adult has returned to King’s Beach, Lynn, and Revere Beach, Revere, from February 2017 to March 2023. It has been identified in the field repeatedly by a worn metal band on its right leg reading 581641. Akila was banded near Akureyri Airport, Iceland, as a pullus (chick) on June 23, 2013. It is a round-headed, small-billed bird, usually showing a complete grayish bill ring, two large mirrors on the outer two primaries, and a broken subterminal band on p5.
   1. *[2017-003R]: age 4, 2/25/2017 to 2/28/2017 [John Quigley* (ph), Joe Bourget (ph), Dan Prima].
   2. *[2018-016]: age 5, 1/20/2018 to 1/21/2018 [Suzanne Sullivan* (ph), John Keeley*].
   3. *[2018-017]: age 5, 2/18/2018 to 2/24/2018 [Dan Burton* (ph), Sean Williams* (ph), m.ob.].
   4. *[2018-074R]: age 6, 11/24/2018 to 2/6/2019 [Suzanne Sullivan* (ph), m.ob.]. Not known to be present during this entire period, with observations only on 11/24, 12/23, and 12/28/2018, and 1/5, 1/9, 1/26, 2/4, 2/5, and 2/6/2019.
   5. *[2020-009R]: age 7, 1/31/2020 to 2/4/2020 and 2/23/2020 [Andy Sanford* (ph), m.ob.].
   6. **[2023-067]: age 10, 1/7/2023 to 3/18/2023 [Suzanne Sullivan* (ph), m.ob.].
7. *[2020-007R]: adult, at Gooseberry Neck, Westport, Bristol, 1/20/2018 [Joel Eckerson* (ph), Matthew Eckerson* (ph), Dan Zimberlin (ph)].
8. Ringer or 74J: This adult is identified by a blue color band on its left leg reading 74J. First identified as a Common Gull in 2018, but it took seven years to learn where it had been banded. Louis Bevier reported the bird as “gull sp.” to <www.reportband.gov> and on February 4, 2025, learned that it had been banded as a Ring-billed Gull on Revere Beach, Suffolk County, December 19, 2013. This misidentification accounted for the difficulty tracing the band. Hodgkins et al. (2025) detail two re-sightings of this bird in Maine—at Rockland Harbor, Knox County, on November 1, 2024, and at Mill Creek Cove, Portland, Cumberland County, on January 18, 2025—along with the remarkable pathway to discover where it first had been banded.
   1. **[2013-071]: at Revere Beach, Suffolk, 12/19/2013. Identified as a Ring-billed Gull when banded. [Andrew Vitz*].
   2. *[2018-020R]: at Sandy Beach, Cohasset, Norfolk, 4/15/2018 to 4/16/2018 [Marshall Iliff* (ph), m.ob.].

Common Gull (Kamchatka) Larus canus kamtschatschensis

Extremely rare in Massachusetts; 20 records involve 3 individuals. This subspecies has been seen almost annually since 2013 thanks to two long-staying, returning birds on Cape Ann and King’s Beach (2007, 2009, and most years 2013–2025) and Nantucket (most years 2013–2025). A single record is of a third individual that visited King’s Beach March 1–15, 2015.

1. Old Reliable: This medium-sized L. c. kamtschatschensis is quite dark on the mantle and usually sports a bright yellow bill without a ring. The bird has a hood of brown smudging, which is more extensive than most L. c. canus, but with sparser streaking, and unlike the well-marked hood of the Nantucket L. c. kamtschatschensis SconsetKam. Unlike SconsetKam, Old Reliable never shows the dark crescent in front of the eye. Like most L. c. kamtschatschensis, it has a very large white mirror on its tenth primary, p10, a moderately large white mirror on p9, and, at least in some years, 11 primaries on its right wing. Records b-e below are here officially revised to kamtschatschensis despite being originally published in the 16th report as kamtschatschensis/heinei (but these records do not have an R as a suffix, because this was not a complete re-review).
   1. [2007-002]: at Jodrey Fish Pier, Gloucester, Essex, 1/2/2007 to 1/3/2007 [Eric Enbody* (ph), David Pavlik* (ph), Rick Heil (ph), Phil Brown (ph)]. Accepted as L. c. kamtschatschensis in the 13th report.
   2. *[2009-055]: at Harbor and Brace coves, East Gloucester, Essex, 11/26/2009 to 12/7/2009 [Rick Heil* (ph), Phil Brown (ph)].
   3. *[2009-056]: at King’s Beach, Lynn, and Swampscott, Essex, 12/8/2009 [Devin Bosler, Margo Goetschkes (ph)].
   4. *[2010-082]: at Niles Pond, Gloucester, Essex, 11/2/2009 to 2/26/2010 [Nick Bonomo* (ph), James P. Smith* (ph), Rick Heil (ph)].
   5. *[2011-032]: at King’s Beach/Lynn Beach, Lynn, Essex, 2/24/2011 to 3/5/2011 [J. Quigley*, Erik Nielsen (ph), Marshall Iliff (ph), Matt Garvey (ph), Suzanne Sullivan (ph)].
   6. **[2013-069]: at King’s Beach/Lynn Beach, Lynn, Essex, 1/10/2013 to 1/20/2013 [Tom Murray* (ph), m.ob.].
   7. **[2015-086]: at King’s Beach/Lynn Beach, Lynn, Essex, 3/7/2015 to 3/11/2015 [Hans Bucht* (ph), Nathan Dubrow* (ph), Ryan Doherty* (ph), m.ob.].
   8. *[2018-018R]: at King’s Beach/Lynn Beach, Lynn, Essex, 2/19/2018 [Peter Vale* (ph), Marshall Iliff (ph), m.ob.].
   9. *[2019-159]: at King’s Beach/Lynn Beach, Lynn, Essex, 1/5/2019 to 2/5/2019 [S. Sullivan* (ph), m.ob.].
   10. *[2020-008R]: at King’s Beach/Lynn Beach, Lynn, Essex, 1/31/2020 to 2/16/2020 [A. Sanford* (ph), m.ob.].
   11. **[2023-068]: at King’s Beach/Lynn Beach, Lynn, Essex, 1/18/2023 to 2/10/2023 [M. Watson* (ph), P. Vale*, S. Sullivan (ph)].
   12. **[2024-008]: at King’s Beach/Lynn Beach, Lynn, Essex, 1/16/2024 to 2/28/2024 [S. Sullivan* (ph), m.ob.].
   13. **[2025-002]: at King’s Beach/Lynn Beach, Lynn, Essex, 1/26/2025 to 1/29/2025, [S. Sullivan* (ph), m.ob.].
2. SconsetKam: This medium-sized L. c. kamtschatschensis, first noted as an adult, has been seen only on Nantucket. It is quite dark on the mantle and sports a bright yellow bill without a ring. It often has an extensive hood of brown smudging that gives it a more hooded look than that of other New England L. c. kamtschatschensis. The hood often has a distinctive, dark crescent in front of the eye. SconsetKam is unique among New England L. c. kamtschatschensis in having a single white mirror on its tenth primary, p10, and an extensively black tip to p9 with just a small white apical spot—no mirror. Old Reliable always shows prominent mirrors on p9 and p10. SconsetKam’s location has been standardized to Siasconset beaches, with sightings ranging from Quidnet Village to Low Beach.
   1. **[2013-068]: 12/30/2013 to 1/1/2014 [Pat Dugan* (ph), F. Gallo (ph), m.ob.].
   2. **[2014-085]: 12/28/2014 [Jeremiah Trimble* (ph), m.ob.].
   3. *[2018-015R]: 1/15/2018 [Jeremiah Trimble* (ph), m.ob.].
   4. *[2020-031R]: 3/28/2020 [Skyler Kardell* (ph)].
   5. [2021-026]: 2/25/2021 to 3/3/2021 [Skyler Kardell (ph), m.ob.].
   6. **[2024-025]: 12/29/2024 to 12/31/2024 [Jeremiah Trimble* (ph), Valerie Burdette (ph)].
3. KamMonster: This extremely large L. c. kamtschatschensis—surely a male because males are larger—is different in structure and plumage from Old Reliable, which is likely a female. Its long bill is duller yellow, and it has a head pattern with fine streaks rather than blotching. In 2015, it had a bold reddish orbital ring and mirrors on just two primaries—p10 and p9; Old Reliable had a third small mirror on p8. What was surely the same bird, consistent in bill structure and wing pattern, was also seen in 2021 in Fairfield and New Haven counties, Connecticut.
   1. **[2015-085]: adult at King’s Beach/Lynn Beach, Lynn, Essex, 3/1/2015 to 3/15/2015 [S. Sullivan* (ph), m.ob.].

Short-billed Gull Larus brachyrhynchus

Extremely rare in the state; four records pertain to four individual adults, all along the coast, thus far only from 2015 to 2019. Other East Coast records are from New Brunswick (1), Maine (3), Connecticut (3), New York (11, 6 upstate and 5 downstate, some of the latter possibly pertaining to a returning same individual [NYSARC 2024]), and Virginia (1). Two records of juveniles cited in Veit and Petersen (1993) require review and confirmation.

1. *[2017-006R]: at Race Point Beach, Provincetown, Barnstable, 4/15/2017 [Will Sweet* (ph)].
2. [2018-085]: at Sandy Beach, Cohasset, Norfolk, 4/15/2018 to 4/16/2018 [Vin Zollo* (ph), Marshall Iliff* (ph), m.ob.].
3. *[2019-040R]: at Race Point Beach, Provincetown, Barnstable, 4/7/2019 [Peter Flood* (ph)].
4. *[2019-123R]: at Broad Cove, Somerset, Bristol, 11/22/2019 [Matthew Eckerson* (ph)].

The 2015 and 2019 Race Point birds appeared to differ somewhat in bill structure, so MARC treats them as different birds.

Among a flock of Ring-billed Gulls, Short-billed Gull (front center) should stand out as smaller, slimmer, and at least a couple shades darker on the back. Sandy Beach, Cohasset; April 15, 2018. Photograph by Marshall J. Iliff. https://macaulaylibrary.org/asset/94808881

Common/Short-billed Gull Larus canus/brachyrhynchus

1. *[1980-005R]: adult at Revere Beach, Revere, Suffolk, 5/9/1980 [Soheil Zendeh* (ph)].
   This breeding-plumaged bird was accepted as Common/Short-billed based on a couple of images, but without open-wing photos the committee has been unable to identify the taxon conclusively; most thought it represented L. c. canus.
2. [1999-004]: adult at Winthrop Beach Breakers, Suffolk, 1/16/1999 [David Larson†*, S. Carlson*].
   This is the only individual from the complex that was accepted based solely on a description with no photos. With no information to indicate which taxon was involved, Larus canus canus seems most likely.
3. [2018-075]: adult at Loblolly Cove, Gloucester, Essex, 11/27/2018 [Ryan Doherty* (ph)].
   This bird can probably be identified as a Common Gull and not a Short-billed Gull, but identification to subspecies may not be possible. The MARC has yet to reassess this record.
4. [2020-010]: adult at Lake Massapoag, Sharon, Norfolk, 2/3/2020 [Will Sweet* (ph)].
   Distant photos of this adult among a dense gull flock show either a Common Gull or a Short-billed Gull, but the committee could not be sure which.

Kamchatka Gulls in the East

The Massachusetts sightings of Kamchatka Gull are part of a pattern of increase across North America, likely due to elevated awareness, vast improvements in and the prevalence of digital photography, and rapid information sharing. Environmental changes and alternations in occurrence patterns likely also play a role.

The first Kamchatka Gull in the eastern United States was found February 15, 2000. George Armistead and Matt Sharp photographed an adult Mew Gull in Delaware, and that established the first L. c. kamtschatschensis (North American Birds 56 (2):159, 253) record for the East Coast—and a first for North America away from Alaska. New England’s first record arrived in January 2006, when Carlos Pedro found a Mew Gull in Providence, Rhode Island, that was confirmed as L. c. kamtschatschensis; it lingered for a couple of months. Thus, a new Mew Gull taxon entered the realm of possibilities for Massachusetts. Less than a year later, Eric Enbody and David Pavlik found a Mew Gull at Jodrey Fish Pier, Gloucester, that was reviewed and accepted in the 13th MARC report as the state’s first L. c. kamtschatschensis. Since then, Kamchatka Gulls have been found in the Eastern United States almost annually—19 out of 20 years between 2006 and 2025. Remarkably, it was not until December 29, 2024, that this taxon was first found on the West Coast south of Alaska, when Alvaro Jaramillo photographed a first-cycle Kamchatka Gull in San Mateo County, California.

The MARC thinks that three returning birds have accounted for all the Massachusetts records. However, it is more difficult to determine how many Kamchatka Gulls have occurred throughout the East. One Connecticut bird is most likely KamMonster; the Stamford, Connecticut, adult represents a fourth individual. Two records from Maine—adults photographed at Payson Park on December 8, 2008, and at Cape Neddick on January 24, 2024—lack spread-wing photographs to confirm them as the same individual; they could pertain to the Stamford bird or to Old Reliable. The Rhode Island bird is not SconsetKam and could be an additional individual, but detailed wing pattern analysis may be needed to eliminate the Stamford bird or Old Reliable. The adult Kamchatka Gull from Digby County, Nova Scotia—March 13–26, 2016; January 21 to April 1, 2017; December 24, 2017, to March 25, 2018—could be a fifth individual but needs a careful review.

One record or many? Assessing same-bird issues in Mew Gulls

The Mew Gull complex has proven to be an especially interesting set of taxa in which to assess same-bird issues. At least two different banded birds have been found in Massachusetts, and each has been sighted in the Northeast repeatedly—one was first banded as a chick in Iceland and the other first banded as an adult in Massachusetts. Cases like this are the most solid, leaving no doubt whatsoever that the same individual was involved.

Correct identification to subspecies is essential to assessing same birds. As birders become more comfortable with identification of Common Gull subspecies, it is easier to recognize when a bird of the same subspecies returns to a given beach in successive years, especially in Lynn, where both L. c. canus and L. c. kamtschatschensis have occurred concurrently.

Careful assessment of wingtip pattern enables birders to identify individual gulls and realize when more than one bird has been present at a given site. The superlative digital photography of the past couple of decades has made this possible. Although wingtip patterns in gulls are known to change slightly over time, the larger pattern of the wingtip—if not the finer details—is usually consistent in between complete molts and across the years.

• Using wingtip pattern assessment, the MARC has been able to answer several questions about Common and Short-billed gulls in Massachusetts:
• Three different Kamchatka Gulls have accounted for all state records: Old Reliable, SconsetKam, and KamMonster.
• KamMonster also occurred in Connecticut, but the long-staying Stamford Kamchatka Gull has not been seen in Massachusetts.
• No other East Coast Kamchatka Gull has yet been proven to pertain to any of the Massachusetts birds.
• Consistency in wingtip pattern has confirmed that adults show site fidelity over the years, with 18 years of records of Old Reliable on the North Shore, 11 years of records of SconsetKam on Nantucket, and 2 successive years when Darktip 2 returned to Race Point.
• Longevity information for Kamchatka Gull is being established through these observations.
• Multiple Mew Gull taxa have been present concurrently at the same site—or within a mile of one another—on no fewer than five occasions in Massachusetts since 2003:
  1. Two L. c. kamtschatschensis—Old Reliable and KamMonster—at King’s Beach/Lynn Beach in March 2015.
  2. Two L. c. canus—Whitetip and Darktip 1—at Race Point Beach and Race Point, Provincetown, in March 2016.
  3. One Short-billed Gull and one L. c. canus within one mile of each other on Race Point Beach, Provincetown, April 15, 2017.
  4. One L. c. kamtschatschensis—Old Reliable—and one L. c. canus—Akila—at King’s Beach/Lynn Beach on several dates, including February 19, 2018.
  5. One Short-billed Gull and one L. c. canus in the same feeding aggregation at Sandy Beach, Cohasset, in April 2018.

The fact that more than one member of the Mew Gull complex has been present at the same site at the same time is remarkable, given the rarity of these birds. This hints at how specialized their feeding requirements appear to be, and at just how good these birds are at finding the locations with appropriate food sources.

Evaluation of photographs for characteristics other than wingtip pattern can also be helpful to assess for same birds. One especially notable discovery from flight photos of Old Reliable was that on January 28, 2024, Miles Brengle and Nathan Dubrow noticed that it has 11 primaries on its right wing. Photographs of the left wing show the expected 10 primaries. Once birders began to look for this unusual feature, it was again noted in 2025 and was recognizable in older photographs, such as Iliff’s from February 19, 2018.

Current perspectives on the Mew Gull complex

The seasonal pattern elucidated by Veit and Petersen (1993) is not reflected in twenty-first-century records. Whereas Veit and Petersen (1993) list two sight records of first-basic Short-billed Gulls in October 1980 and September 1981, three of four contemporary records of adult Short-billed Gull are concentrated in a narrow spring window in April, and the one exceptional fall record is later in November.

eBird shows few records of Short-billed Gull east of the Mississippi River during June through September. An adult at Rockland, Maine, in August 2013 (Maine Bird Records Committee 2025) shows that outlier occurrences are possible, but the occurrence of first-cycle Short-billed Gull in eastern North America in September and early October is extremely unlikely, given that few even reach the Pacific coast states that early.

Though all Massachusetts records of Kamchatka Gull are attributable to three individuals, since 2006 more observations have involved L. c. kamtschatschensis than L. c. canus; this article reports 19 observations of L. c. kamtschatschensis in Massachusetts versus 14 of L. c. canus. Kamchatka Gull was not known to occur in North America away from Alaska until 2000. Its recent appearance likely reflects an increase in observer awareness—and ability to document records—along with a true change in status.

Melting of Arctic ice has opened new pathways for movement of high Arctic taxa. Recent patterns of vagrancy across many species show that we are seeing increased interchange of marine species between the Atlantic and the Pacific. Pacific records of Northern Gannet (Morus bassanus) in California and Great Black-backed Gull (Larus marinus) in northern Alaska suggest westward movement of Atlantic taxa. Recent Atlantic and interior records of Slaty-backed Gull (Larus schistisagus), Vega Gull (Larus vegae), Black-tailed Gull (Larus crassirostris), Tufted Puffin (Fratercula cirrhata), and Short-tailed Shearwater (Ardenna tenuirostris) suggest a pattern of autumn dispersal eastward through the unfrozen Arctic, with southward movement as cold weather and sea ice set in. It seems quite likely that recent L. c. kamtschatschensis are part of that same pattern.

The lack of documentation of sightings of Mew Gulls before 1993 is frustrating and the early status of the Mew Gull complex in the state will remain shrouded in mystery despite the huge changes in understanding of these taxa, identification criteria, and taxonomy. Without documentation, it will never be known whether the occurrence of L. c. kamtschatschensis is a modern phenomenon driven by thawing of the Arctic ice that allows movement via the Northwest passage or whether this taxon has long been overlooked in the Northeast. As always, the Massachusetts Avian Records Committee welcomes documentation—especially photos—for any records not included in this report that might help further clarify the status of the Mew Gull complex in Massachusetts.

I would like to thank Sebastian Jones, secretary of MARC, for a careful review of this paper. Thanks also to the MARC members that voted on these records, including Ted Gilliland, Lily Morello, Lisa Schibley, Jim Sweeney, Larry Therrien, Jeremiah Trimble, Liam Waters, and Maili Waters.

REFERENCES

• Adriaens, P. and C. N. Gibbins. 2016. Identification of the Larus canus complex. Dutch Birding 38:1–64.
• Bevier, L. and T. Persons. 2025. The Fourteenth Report of the Maine Bird Records Committee. Bird Observer 53 (2):103–09.
• Burgiel, J. C., R.O. Paxton, and D. A. Cutler. 2002. Hudson-Delaware. North American Birds 56 (2):159, photograph 253.
• Hodgkins, G., M. Weber, and A. Hodgkins. 2025. The (Rare) Common Gull (Larus canus) in Maine—a Species Split and the Curious Case of a New England-banded European Gull. Maine Natural History Observer 2:14–25.
• Maine Bird Records Committee. 2025. <https://sites.google.com/site/mainebirdrecordscommittee/official-list-of-maine-birds/short-billed-gull?authuser=0. Accessed August 9, 2025>.
• New York State Avian Records Committee. 2024. <https://nybirds.org/NYSARC/HistData/SBIG.htm. Accessed August 6, 2025>.
• Rasmussen, P. C. 2020. Split Mew Gull Larus canus brachyrhynchus and rename as Short-billed Gull. Proposal 221-A-3 to the North American Classification Committee. <https://americanornithology.org/wp-content/uploads/2020/12/2021-A-revised.pdf> Accessed August 9, 2025.
• Sibley, D. A. 2021. Mew Gull is now two species! How to identify Common Gull and Short-billed Gull. <https://www.sibleyguides.com/2021/07/mew-gull-is-now-two-species-how-to-identify-common-gull-and-short-billed-gull/> Accessed August 9, 2025.
• Veit, R. R. and W. R. Petersen. 1993. Birds of Massachusetts. Lincoln, Massachusetts: Massachusetts Audubon Society.
• Williams, S. M., J. Johnson, and M. J. Iliff. 2020. Twenty-fourth Report of the Massachusetts Avian Records Committee. Bird Observer 48 (6):385–406.

Marshall J. Iliff works remotely as Project Leader for eBird, focusing on data quality and taxonomy for the free, online database that now includes over two billion bird observations from around the world. He has lived in Massachusetts since 2006 and is currently serving a second term as chair of the Massachusetts Avian Records Committee. He lives in Dedham, Massachusetts, with his wife, son, and two dogs, and splits most of his birding between Millennium Park, right next door, and Gooseberry Neck, Westport, when he needs a dose of salt spray and coastal bird migration.

Table 1. Revised MARC records that were accepted between 2003 and 2020.