WhenToBird

Somateria mollissima · Anatidae

When Do Common Eiders Arrive in New Jersey?

Adult male Common Eider
Photo: Christoph Moning, CC BY 4.0 via iNaturalist

Common Eiders are winter birds in New Jersey: they arrive in the second week of November, peak in mid January (2.5% of checklists), and most are gone by the second week of March.

When to look

First arrivalsNov 8-14the second week of November
Common byNov 8-14the second week of November
PeakJan 15-21mid January
Most gone byMar 8-14the second week of March

Best: mid January. First arrivals the second week of November; most are gone by the second week of March. Peak: on about 2.5% of New Jersey checklists.

  1. Janpeak season
  2. Febcommon
  3. Marcommon
  4. Aprrare
  5. Mayrare
  6. Junrare
  7. Julrare
  8. Augrare
  9. Seprare
  10. Octuncommon
  11. Novcommon
  12. Decpeak season

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

0%1%2%3%4%Jan 1-7: 2.0% of 28167 checklistsJan 8-14: 2.8% of 20583 checklistsJan 15-21: 3.1% of 19739 checklistsJan 22-31: 1.9% of 24586 checklistsFeb 1-7: 1.7% of 17226 checklistsFeb 8-14: 1.5% of 19567 checklistsFeb 15-21: 1.1% of 26553 checklistsFeb 22-28: 1.4% of 19046 checklistsMar 1-7: 1.1% of 17969 checklistsMar 8-14: 1.0% of 18976 checklistsMar 15-21: 0.7% of 18581 checklistsMar 22-31: 0.3% of 27590 checklistsApr 1-7: 0.2% of 21202 checklistsApr 8-14: 0.2% of 23609 checklistsApr 15-21: 0.1% of 25056 checklistsApr 22-30: 0.1% of 36679 checklistsMay 1-7: 0.1% of 38378 checklistsMay 8-14: 0.1% of 44071 checklistsMay 15-21: 0.1% of 34076 checklistsMay 22-31: 0.1% of 32558 checklistsJun 1-7: 0.1% of 18049 checklistsJun 8-14: 0.1% of 15597 checklistsJun 15-21: 0.2% of 14894 checklistsJun 22-30: 0.1% of 17187 checklistsJul 1-7: 0.1% of 13406 checklistsJul 8-14: 0.1% of 12550 checklistsJul 15-21: 0.1% of 12358 checklistsJul 22-31: 0.1% of 18382 checklistsAug 1-7: 0.1% of 13689 checklistsAug 8-14: 0.1% of 14006 checklistsAug 15-21: 0.1% of 14483 checklistsAug 22-31: 0.1% of 23182 checklistsSep 1-7: 0.1% of 17984 checklistsSep 8-14: 0.1% of 18320 checklistsSep 15-21: 0.1% of 20491 checklistsSep 22-30: 0.2% of 26176 checklistsOct 1-7: 0.2% of 24112 checklistsOct 8-14: 0.2% of 24603 checklistsOct 15-21: 0.2% of 24549 checklistsOct 22-31: 0.3% of 26206 checklistsNov 1-7: 0.7% of 17469 checklistsNov 8-14: 1.0% of 15102 checklistsNov 15-21: 1.2% of 14958 checklistsNov 22-30: 1.6% of 19447 checklistsDec 1-7: 2.2% of 14017 checklistsDec 8-14: 2.0% of 14625 checklistsDec 15-21: 1.2% of 16937 checklistsDec 22-31: 2.5% 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. Ocean CountyBest mid January · 2447 checklists that week, 87,340 in all13%
  2. Monmouth CountyBest the second week of January · 2064 checklists that week, 79,748 in all5.0%
  3. Cape May CountyBest mid January · 2533 checklists that week, 189,832 in all3.3%
  4. Atlantic CountyBest early January · 654 checklists that week, 28,208 in all1.8%
  5. Middlesex CountyBest the second week of March · 816 checklists that week, 46,761 in all0.4%

Best spots

Share of checklists at the peak
  1. Barnegat Lighthouse State ParkOcean County, best early December · 225 checklists that week, 6,257 in all73%
  2. Avalon Borough Beach or Boardwalk (Cornell Harbor)Cape May County, best mid January · 22 checklists that week, 149 in all67%
  3. Island Beach State Park (south)Ocean County, best the second week of January · 40 checklists that week, 502 in all58%
  4. East Long BranchMonmouth County, best early December · 29 checklists that week, 519 in all55%

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

Best time of day

In New Jersey, the Common Eider is most often listed on checklists started between 11 am and 1 pm (1.0% of those checklists).

0%0.5%1%1.5%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: 0.4% of 50447 checklists7 am: 0.5% of 118312 checklists8 am: 0.7% of 123273 checklists9 am: 0.9% of 107783 checklists10 am: 1.0% of 97537 checklists11 am: 1.0% of 82427 checklists12 pm: 1.1% of 72581 checklists1 pm: 0.9% of 71478 checklists2 pm: 0.8% of 69994 checklists3 pm: 0.6% of 66822 checklists4 pm: 0.3% of 55950 checklists5 pm: 0.2% of 41360 checklists6 pm: 0.1% 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
January2.0%2.8%3.1%1.9%
February1.7%1.5%1.1%1.4%
March1.1%1.0%0.7%0.3%
April0.2%0.2%0.1%0.1%
May0.1%0.1%0.1%0.1%
June0.1%0.1%0.2%0.1%
July0.1%0.1%0.1%0.1%
August0.1%0.1%0.1%0.1%
September0.1%0.1%0.1%0.2%
October0.2%0.2%0.2%0.3%
November0.7%1.0%1.2%1.6%
December2.2%2.0%1.2%2.5%

Neighboring states

  • Delaware: arrives the second week of November, in the same week than New Jersey
  • Connecticut: arrives the second week of November, in the same week than New Jersey
  • New York: arrives mid November, 1 week later than New Jersey
  • Rhode Island: arrives the second week of November, in the same week than New Jersey

Common questions

When do Common Eiders arrive in New Jersey?
Common Eiders are winter birds in New Jersey: they arrive in the second week of November, peak in mid January (2.5% of checklists), and most are gone by the second week of March.
When do Common Eiders leave New Jersey?
Most Common Eiders have left New Jersey by the second week of March, when reports fall below half their usual rate.
When is the best time to see a Common Eider in New Jersey?
The Common Eider is reported most often in mid January, on about 2.5% of New Jersey checklists.
Where in New Jersey are Common Eiders seen most often?
By county, Ocean County, Monmouth County, and Cape May County have the highest peak reporting rates for the Common Eider (counties with at least 200 checklists).