WhenToBird

Larus fuscus · Laridae

When Do Lesser Black-backed Gulls Arrive in Maine?

Adult Lesser Black-backed Gull
Photo: danielarah, CC0 1.0 via iNaturalist

Lesser Black-backed Gulls mostly pass through Maine: they arrive in mid August, peak in the second week of September (1.4% of checklists), and most are gone by mid October.

When to look

First arrivalsAug 15-21mid August
Common byAug 15-21mid August
PeakSep 8-14the second week of September
Most gone byOct 15-21mid October

Best: the second week of September. First arrivals mid August; most are gone by mid October. Peak: on about 1.4% of Maine checklists.

  1. Janrare
  2. Febrare
  3. Marrare
  4. Apruncommon
  5. Mayrare
  6. Junrare
  7. Julrare
  8. Augcommon
  9. Seppeak season
  10. Octcommon
  11. Novuncommon
  12. Decrare

Darker months: more checklists report it. Outlined: peak month.

0%0.5%1%1.5%2%Jan 1-7: 0.1% of 15499 checklistsJan 8-14: 0.2% of 11141 checklistsJan 15-21: 0.2% of 10729 checklistsJan 22-31: 0.1% of 15084 checklistsFeb 1-7: 0.3% of 9403 checklistsFeb 8-14: 0.1% of 11268 checklistsFeb 15-21: 0.1% of 14061 checklistsFeb 22-28: 0.1% of 9977 checklistsMar 1-7: 0.1% of 9649 checklistsMar 8-14: 0.1% of 11781 checklistsMar 15-21: 0.1% of 11613 checklistsMar 22-31: 0.1% of 17798 checklistsApr 1-7: 0.2% of 14638 checklistsApr 8-14: 0.2% of 16511 checklistsApr 15-21: 0.2% of 17164 checklistsApr 22-30: 0.2% of 22602 checklistsMay 1-7: 0.2% of 22556 checklistsMay 8-14: 0.1% of 27842 checklistsMay 15-21: 0.1% of 27748 checklistsMay 22-31: 0.1% of 38715 checklistsJun 1-7: 0.1% of 26916 checklistsJun 8-14: 0.1% of 23737 checklistsJun 15-21: 0.1% of 22733 checklistsJun 22-30: 0.1% of 28248 checklistsJul 1-7: 0.1% of 20290 checklistsJul 8-14: 0.1% of 18534 checklistsJul 15-21: 0.1% of 17319 checklistsJul 22-31: 0.1% of 22815 checklistsAug 1-7: 0.2% of 15004 checklistsAug 8-14: 0.1% of 14603 checklistsAug 15-21: 0.4% of 14972 checklistsAug 22-31: 0.6% of 19813 checklistsSep 1-7: 1.1% of 14567 checklistsSep 8-14: 1.4% of 14520 checklistsSep 15-21: 1.6% of 14339 checklistsSep 22-30: 1.0% of 16879 checklistsOct 1-7: 0.6% of 12959 checklistsOct 8-14: 0.5% of 13168 checklistsOct 15-21: 0.3% of 11184 checklistsOct 22-31: 0.3% of 13717 checklistsNov 1-7: 0.3% of 9823 checklistsNov 8-14: 0.4% of 9007 checklistsNov 15-21: 0.3% of 8528 checklistsNov 22-30: 0.2% of 10228 checklistsDec 1-7: 0.1% of 7505 checklistsDec 8-14: 0.1% of 7982 checklistsDec 15-21: 0.1% of 10455 checklistsDec 22-31: 0.1% of 14285 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
Share of complete checklists reporting it, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.

Frequency is the share of complete checklists in Maine that listed the bird, 2016–2025. It is not a head count, and it follows where and when people go birding. How to read it.

JanFebMarAprMayJunJulAugSepOctNovDec
today
Second week of November

Each county is shaded by the share of complete checklists there that listed the bird, blended with the weeks either side. Darker is more often. It follows where people watch birds, not how many birds there are. How to read it.

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Where in Maine

Best counties

Share of checklists at the peak
  1. York CountyBest the second week of September · 1999 checklists that week, 101,844 in all4.4%
  2. Sagadahoc CountyBest the second week of September · 423 checklists that week, 21,736 in all3.3%
  3. Lincoln CountyBest late September · 2193 checklists that week, 59,429 in all2.9%
  4. Aroostook CountyBest the second week of April · 206 checklists that week, 16,817 in all2.0%
  5. Washington CountyBest late January · 330 checklists that week, 35,967 in all1.7%
  6. Knox CountyBest the second week of November · 424 checklists that week, 34,453 in all1.2%

Best spots

Share of checklists at the peak
  1. Back BayYork County, best the second week of September · 99 checklists that week, 1,607 in all35%
  2. Saccarappa FallsCumberland County, best mid January · 25 checklists that week, 267 in all23%
  3. The PoolYork County, best the second week of September · 33 checklists that week, 685 in all18%
  4. Seawall Pond (Seawall Point)Hancock County, best the second week of September · 29 checklists that week, 690 in all18%
  5. Cobscook Bay Wildlife Management AreaWashington County, best mid September · 27 checklists that week, 569 in all16%
  6. Popham Beach State ParkSagadahoc County, best early September · 34 checklists that week, 749 in all16%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In Maine, the Lesser Black-backed Gull is most often listed on checklists started between 3 and 5 pm (0.3% of those checklists).

0%0.5%12 am: too few checklists (510) to judge1 am: too few checklists (517) to judge2 am: too few checklists (581) to judge3 am: too few checklists (3242) to judge4 am: too few checklists (7221) to judge5 am: 0.2% of 19895 checklists6 am: 0.3% of 54578 checklists7 am: 0.2% of 92775 checklists8 am: 0.2% of 86962 checklists9 am: 0.2% of 78989 checklists10 am: 0.2% of 70954 checklists11 am: 0.3% of 59331 checklists12 pm: 0.3% of 50943 checklists1 pm: 0.3% of 49775 checklists2 pm: 0.3% of 49001 checklists3 pm: 0.3% of 43252 checklists4 pm: 0.3% of 33413 checklists5 pm: 0.3% of 25547 checklists6 pm: 0.3% of 18309 checklists7 pm: too few checklists (14287) to judge8 pm: too few checklists (5336) to judge9 pm: too few checklists (2253) to judge10 pm: too few checklists (1518) to judge11 pm: too few checklists (720) to judge12a3a6a9a12p3p6p9p
Share of checklists started in each local hour that reported it. It reflects when people go birding as well as when birds are active. Grey hours have too few checklists (under 2% of the state’s, or under 200) to judge.
Week-by-week table
MonthDays 1-78-1415-2122-end
January0.1%0.2%0.2%0.1%
February0.3%0.1%0.1%0.1%
March0.1%0.1%0.1%0.1%
April0.2%0.2%0.2%0.2%
May0.2%0.1%0.1%0.1%
June0.1%0.1%0.1%0.1%
July0.1%0.1%0.1%0.1%
August0.2%0.1%0.4%0.6%
September1.1%1.4%1.6%1.0%
October0.6%0.5%0.3%0.3%
November0.3%0.4%0.3%0.2%
December0.1%0.1%0.1%0.1%

Neighboring states

  • Massachusetts: arrives mid June, 8 weeks earlier than Maine
  • Rhode Island: arrives mid July, 4 weeks earlier than Maine
  • New York: arrives late May, 11 weeks earlier than Maine
  • New Jersey: arrives late June, 7 weeks earlier than Maine

Common questions

When do Lesser Black-backed Gulls arrive in Maine?
Lesser Black-backed Gulls mostly pass through Maine: they arrive in mid August, peak in the second week of September (1.4% of checklists), and most are gone by mid October.
When do Lesser Black-backed Gulls leave Maine?
Most Lesser Black-backed Gulls have left Maine by mid October, when reports fall below half their usual rate.
When is the best time to see a Lesser Black-backed Gull in Maine?
The Lesser Black-backed Gull is reported most often in the second week of September, on about 1.4% of Maine checklists.
Where in Maine are Lesser Black-backed Gulls seen most often?
By county, York County, Sagadahoc County, and Lincoln County have the highest peak reporting rates for the Lesser Black-backed Gull (counties with at least 200 checklists).