WhenToBird

Nannopterum auritum · Phalacrocoracidae

When Do Double-crested Cormorants Arrive in New Jersey?

Adult Double-crested Cormorant
Photo: jubileej, CC0 1.0 via iNaturalist

Double-crested Cormorants are in New Jersey all year, but most are here in fall: numbers build from mid July, peak in mid October (29% of checklists), and fall back by mid November. In the quietest week (mid February) they are still on about 6.1% of checklists.

When to look

Numbers buildJul 15-21mid July
PeakOct 15-21mid October
Fall back byNov 15-21mid November
FewestFeb 15-21mid February

Best: mid October. Here all year; numbers build from mid July and fall back by mid November. Peak: on about 29% of New Jersey checklists.

  1. Januncommon
  2. Febuncommon
  3. Marcommon
  4. Aprpeak season
  5. Maycommon
  6. Juncommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

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

0%10%20%30%Jan 1-7: 8.7% of 28167 checklistsJan 8-14: 8.2% of 20583 checklistsJan 15-21: 7.6% of 19739 checklistsJan 22-31: 7.3% of 24586 checklistsFeb 1-7: 6.8% of 17226 checklistsFeb 8-14: 6.5% of 19567 checklistsFeb 15-21: 5.4% of 26553 checklistsFeb 22-28: 6.6% of 19046 checklistsMar 1-7: 7.5% of 17969 checklistsMar 8-14: 8.5% of 18976 checklistsMar 15-21: 11% of 18581 checklistsMar 22-31: 17% of 27590 checklistsApr 1-7: 23% of 21202 checklistsApr 8-14: 25% of 23609 checklistsApr 15-21: 24% of 25056 checklistsApr 22-30: 22% of 36679 checklistsMay 1-7: 19% of 38378 checklistsMay 8-14: 19% of 44071 checklistsMay 15-21: 21% of 34076 checklistsMay 22-31: 19% of 32558 checklistsJun 1-7: 16% of 18049 checklistsJun 8-14: 16% of 15597 checklistsJun 15-21: 16% of 14894 checklistsJun 22-30: 15% of 17187 checklistsJul 1-7: 16% of 13406 checklistsJul 8-14: 17% of 12550 checklistsJul 15-21: 19% of 12358 checklistsJul 22-31: 21% of 18382 checklistsAug 1-7: 22% of 13689 checklistsAug 8-14: 23% of 14006 checklistsAug 15-21: 24% of 14483 checklistsAug 22-31: 22% of 23182 checklistsSep 1-7: 23% of 17984 checklistsSep 8-14: 23% of 18320 checklistsSep 15-21: 25% of 20491 checklistsSep 22-30: 25% of 26176 checklistsOct 1-7: 27% of 24112 checklistsOct 8-14: 28% of 24603 checklistsOct 15-21: 30% of 24549 checklistsOct 22-31: 29% of 26206 checklistsNov 1-7: 25% of 17469 checklistsNov 8-14: 23% of 15102 checklistsNov 15-21: 18% of 14958 checklistsNov 22-30: 15% of 19447 checklistsDec 1-7: 14% of 14017 checklistsDec 8-14: 11% of 14625 checklistsDec 15-21: 8.8% of 16937 checklistsDec 22-31: 8.3% 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. Hudson CountyBest late August · 571 checklists that week, 21,191 in all58%
  2. Cumberland CountyBest mid September · 162 checklists that week, 13,927 in all46%
  3. Cape May CountyBest late October · 7449 checklists that week, 189,832 in all45%
  4. Bergen CountyBest late July · 1444 checklists that week, 73,457 in all40%
  5. Passaic CountyBest the second week of April · 778 checklists that week, 24,933 in all37%
  6. Atlantic CountyBest mid October · 546 checklists that week, 28,208 in all37%

Best spots

Share of checklists at the peak
  1. Carnegie LakeMercer County, best early October · 21 checklists that week, 1,444 in all100%
  2. SlaterUnion County, best the second week of July · 22 checklists that week, 995 in all100%
  3. Heathcote BrookMercer County, best early October · 22 checklists that week, 777 in all100%
  4. Island Beach State Park (Sedge Islands)Ocean County, best the second week of August · 20 checklists that week, 211 in all100%
  5. Cape May Point State Park (Sunset Beach)Cape May County, best mid April · 31 checklists that week, 2,113 in all99%
  6. Reeds BeachCape May County, best early October · 22 checklists that week, 1,032 in all98%

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

Best time of day

In New Jersey, the Double-crested Cormorant is most often listed on checklists started between 6 and 8 am (22% of those checklists).

0%10%20%30%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: 26% of 50447 checklists7 am: 20% of 118312 checklists8 am: 17% of 123273 checklists9 am: 18% of 107783 checklists10 am: 19% of 97537 checklists11 am: 17% of 82427 checklists12 pm: 16% of 72581 checklists1 pm: 17% of 71478 checklists2 pm: 17% of 69994 checklists3 pm: 17% of 66822 checklists4 pm: 16% of 55950 checklists5 pm: 16% of 41360 checklists6 pm: 13% 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
January8.7%8.2%7.6%7.3%
February6.8%6.5%5.4%6.6%
March7.5%8.5%11%17%
April23%25%24%22%
May19%19%21%19%
June16%16%16%15%
July16%17%19%21%
August22%23%24%22%
September23%23%25%25%
October27%28%30%29%
November25%23%18%15%
December14%11%8.8%8.3%

Neighboring states

  • Delaware: arrives mid July, in the same week than New Jersey
  • Connecticut: arrives mid March, 16 weeks earlier than New Jersey
  • Pennsylvania: arrives the second week of March, 17 weeks earlier than New Jersey
  • New York: arrives the second week of July, 1 week earlier than New Jersey

Common questions

When do Double-crested Cormorants arrive in New Jersey?
Double-crested Cormorants are in New Jersey all year, but most are here in fall: numbers build from mid July, peak in mid October (29% of checklists), and fall back by mid November. In the quietest week (mid February) they are still on about 6.1% of checklists.
When do Double-crested Cormorants leave New Jersey?
Double-crested Cormorants never fully leave New Jersey: numbers fall back below half their usual rate by mid November, but some are still reported in every week, about 6.1% of checklists at the low.
When is the best time to see a Double-crested Cormorant in New Jersey?
The Double-crested Cormorant is reported most often in mid October, on about 29% of New Jersey checklists.
Where in New Jersey are Double-crested Cormorants seen most often?
By county, Hudson County, Cumberland County, and Cape May County have the highest peak reporting rates for the Double-crested Cormorant (counties with at least 200 checklists).