WhenToBird

Larus marinus · Laridae

When Do Great Black-backed Gulls Arrive in New Jersey?

Adult Great Black-backed Gull
Photo: Rob Wadsworth, CC0 1.0 via iNaturalist

The Great Black-backed Gull is in New Jersey all year. It turns up on about 17% of checklists at its peak (mid January) and on 7.9% in its quietest week (late April).

When to look

PresentAll year
Peak weekJan 15-21mid January
Quietest weekApr 22-30late April

Best: mid January. Here all year. Peak: on about 17% of New Jersey checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Aprcommon
  5. Maycommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%5%10%15%20%Jan 1-7: 17% of 28167 checklistsJan 8-14: 17% of 20583 checklistsJan 15-21: 18% of 19739 checklistsJan 22-31: 17% of 24586 checklistsFeb 1-7: 16% of 17226 checklistsFeb 8-14: 14% of 19567 checklistsFeb 15-21: 12% of 26553 checklistsFeb 22-28: 14% of 19046 checklistsMar 1-7: 12% of 17969 checklistsMar 8-14: 13% of 18976 checklistsMar 15-21: 12% of 18581 checklistsMar 22-31: 11% of 27590 checklistsApr 1-7: 11% of 21202 checklistsApr 8-14: 9.7% of 23609 checklistsApr 15-21: 8.8% of 25056 checklistsApr 22-30: 7.7% of 36679 checklistsMay 1-7: 7.6% of 38378 checklistsMay 8-14: 8.8% of 44071 checklistsMay 15-21: 11% of 34076 checklistsMay 22-31: 11% of 32558 checklistsJun 1-7: 9.4% of 18049 checklistsJun 8-14: 10% of 15597 checklistsJun 15-21: 11% of 14894 checklistsJun 22-30: 11% of 17187 checklistsJul 1-7: 11% of 13406 checklistsJul 8-14: 12% of 12550 checklistsJul 15-21: 14% of 12358 checklistsJul 22-31: 15% of 18382 checklistsAug 1-7: 15% of 13689 checklistsAug 8-14: 16% of 14006 checklistsAug 15-21: 17% of 14483 checklistsAug 22-31: 14% of 23182 checklistsSep 1-7: 14% of 17984 checklistsSep 8-14: 14% of 18320 checklistsSep 15-21: 15% of 20491 checklistsSep 22-30: 16% of 26176 checklistsOct 1-7: 17% of 24112 checklistsOct 8-14: 17% of 24603 checklistsOct 15-21: 18% of 24549 checklistsOct 22-31: 17% of 26206 checklistsNov 1-7: 15% of 17469 checklistsNov 8-14: 15% of 15102 checklistsNov 15-21: 14% of 14958 checklistsNov 22-30: 15% of 19447 checklistsDec 1-7: 15% of 14017 checklistsDec 8-14: 14% of 14625 checklistsDec 15-21: 14% of 16937 checklistsDec 22-31: 15% of 26651 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 New Jersey 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 New Jersey

Best counties

Share of checklists at the peak
  1. Cape May CountyBest the second week of August · 2515 checklists that week, 189,832 in all42%
  2. Ocean CountyBest mid January · 2447 checklists that week, 87,340 in all36%
  3. Monmouth CountyBest the second week of January · 2064 checklists that week, 79,748 in all33%
  4. Hudson CountyBest the second week of January · 390 checklists that week, 21,191 in all32%
  5. Cumberland CountyBest late May · 763 checklists that week, 13,927 in all28%
  6. Middlesex CountyBest early February · 869 checklists that week, 46,761 in all22%

Best spots

Share of checklists at the peak
  1. Island Beach State Park (Sedge Islands)Ocean County, best the second week of August · 20 checklists that week, 211 in all98%
  2. Cape May Point BeachCape May County, best late August · 69 checklists that week, 5,796 in all96%
  3. Island Beach State Park (south)Ocean County, best late July · 21 checklists that week, 502 in all96%
  4. River Road Park (Northwest Reach)Middlesex County, best early February · 30 checklists that week, 505 in all96%
  5. Silver LakeMonmouth County, best mid August · 20 checklists that week, 2,110 in all95%
  6. Fishing CreekCape May County, best the second week of March · 60 checklists that week, 999 in all95%

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

Best time of day

In New Jersey, the Great Black-backed Gull is most often listed on checklists started between 1 and 3 pm (15% of those checklists).

0%5%10%15%20%12 am: too few checklists (746) to judge1 am: too few checklists (640) to judge2 am: too few checklists (606) to judge3 am: too few checklists (755) to judge4 am: too few checklists (1681) to judge5 am: too few checklists (11258) to judge6 am: 16% of 50447 checklists7 am: 13% of 118312 checklists8 am: 12% of 123273 checklists9 am: 13% of 107783 checklists10 am: 14% of 97537 checklists11 am: 14% of 82427 checklists12 pm: 14% of 72581 checklists1 pm: 15% of 71478 checklists2 pm: 15% of 69994 checklists3 pm: 14% of 66822 checklists4 pm: 12% of 55950 checklists5 pm: 11% of 41360 checklists6 pm: 9.4% of 28122 checklists7 pm: too few checklists (14727) to judge8 pm: too few checklists (4257) to judge9 pm: too few checklists (1273) to judge10 pm: too few checklists (920) to judge11 pm: too few checklists (693) 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
January17%17%18%17%
February16%14%12%14%
March12%13%12%11%
April11%9.7%8.8%7.7%
May7.6%8.8%11%11%
June9.4%10%11%11%
July11%12%14%15%
August15%16%17%14%
September14%14%15%16%
October17%17%18%17%
November15%15%14%15%
December15%14%14%15%

Neighboring states

  • Delaware: all year, most in winter, peaks the second week of January
  • Connecticut: all year, most in summer, peaks the second week of August
  • Pennsylvania: winter visitor, peaks the second week of January
  • New York: all year, most in winter, peaks the second week of January

Common questions

When do Great Black-backed Gulls arrive in New Jersey?
The Great Black-backed Gull is in New Jersey all year. It turns up on about 17% of checklists at its peak (mid January) and on 7.9% in its quietest week (late April).
When do Great Black-backed Gulls leave New Jersey?
The Great Black-backed Gull does not leave New Jersey: it is reported all year, from 7.9% of checklists in late April to 17% in mid January.
When is the best time to see a Great Black-backed Gull in New Jersey?
The Great Black-backed Gull is reported most often in mid January, on about 17% of New Jersey checklists.
Where in New Jersey are Great Black-backed Gulls seen most often?
By county, Cape May County, Ocean County, and Monmouth County have the highest peak reporting rates for the Great Black-backed Gull (counties with at least 200 checklists).