WhenToBird

Lophodytes cucullatus · Anatidae

When Do Hooded Mergansers Arrive in New Jersey?

Adult male Hooded Merganser
Photo: Justin Flint, CC BY 4.0 via iNaturalist

Hooded Mergansers are winter birds in New Jersey: the first arrive in late October, they are common by the second week of November, peak in the second week of January (14% of checklists), and most are gone by mid March.

When to look

First arrivalsOct 22-31late October
Common byNov 8-14the second week of November
PeakJan 8-14the second week of January
Most gone byMar 15-21mid March

Best: the second week of January. First arrivals late October; most are gone by mid March. Peak: on about 14% of New Jersey checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Apruncommon
  5. Maynot usually seen
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octrare
  11. Novpeak season
  12. Decpeak season

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

0%5%10%15%Jan 1-7: 14% of 28167 checklistsJan 8-14: 14% of 20583 checklistsJan 15-21: 14% of 19739 checklistsJan 22-31: 13% of 24586 checklistsFeb 1-7: 13% of 17226 checklistsFeb 8-14: 12% of 19567 checklistsFeb 15-21: 11% of 26553 checklistsFeb 22-28: 14% of 19046 checklistsMar 1-7: 13% of 17969 checklistsMar 8-14: 11% of 18976 checklistsMar 15-21: 7.8% of 18581 checklistsMar 22-31: 5.6% of 27590 checklistsApr 1-7: 3.8% of 21202 checklistsApr 8-14: 2.2% of 23609 checklistsApr 15-21: 1.2% of 25056 checklistsApr 22-30: 0.7% of 36679 checklistsMay 1-7: 0.4% of 38378 checklistsMay 8-14: 0.3% of 44071 checklistsMay 15-21: 0.2% of 34076 checklistsMay 22-31: 0.3% of 32558 checklistsJun 1-7: 0.3% of 18049 checklistsJun 8-14: 0.3% of 15597 checklistsJun 15-21: 0.2% of 14894 checklistsJun 22-30: 0.2% of 17187 checklistsJul 1-7: 0.2% of 13406 checklistsJul 8-14: 0.2% of 12550 checklistsJul 15-21: 0.1% of 12358 checklistsJul 22-31: 0.1% of 18382 checklistsAug 1-7: 0.2% of 13689 checklistsAug 8-14: 0.1% of 14006 checklistsAug 15-21: 0.2% of 14483 checklistsAug 22-31: 0.1% of 23182 checklistsSep 1-7: 0.2% of 17984 checklistsSep 8-14: 0.1% of 18320 checklistsSep 15-21: 0.1% of 20491 checklistsSep 22-30: 0.1% of 26176 checklistsOct 1-7: 0.1% of 24112 checklistsOct 8-14: 0.2% of 24603 checklistsOct 15-21: 0.3% of 24549 checklistsOct 22-31: 1.5% of 26206 checklistsNov 1-7: 4.5% of 17469 checklistsNov 8-14: 7.9% of 15102 checklistsNov 15-21: 10% of 14958 checklistsNov 22-30: 12% of 19447 checklistsDec 1-7: 14% of 14017 checklistsDec 8-14: 13% of 14625 checklistsDec 15-21: 12% of 16937 checklistsDec 22-31: 12% 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. Passaic CountyBest early March · 390 checklists that week, 24,933 in all28%
  2. Atlantic CountyBest late November · 580 checklists that week, 28,208 in all24%
  3. Morris CountyBest early March · 1139 checklists that week, 59,212 in all23%
  4. Monmouth CountyBest mid January · 1973 checklists that week, 79,748 in all22%
  5. Bergen CountyBest late February · 1347 checklists that week, 73,457 in all21%
  6. Sussex CountyBest early March · 487 checklists that week, 30,305 in all21%

Best spots

Share of checklists at the peak
  1. Hoey Avenue ParkMonmouth County, best early January · 23 checklists that week, 170 in all98%
  2. Lake Musconetcong State ParkMorris County, best late November · 36 checklists that week, 688 in all93%
  3. Lake CarasaljoOcean County, best late November · 39 checklists that week, 1,087 in all93%
  4. Point View ReservoirPassaic County, best mid December · 20 checklists that week, 487 in all93%
  5. Deer Head LakeOcean County, best early January · 37 checklists that week, 241 in all88%

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

Best time of day

In New Jersey, the Hooded Merganser is most often listed on checklists started between 1 and 3 pm (6.4% of those checklists).

0%2%4%6%8%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: 2.5% of 50447 checklists7 am: 3.8% of 118312 checklists8 am: 4.6% of 123273 checklists9 am: 4.9% of 107783 checklists10 am: 5.5% of 97537 checklists11 am: 5.9% of 82427 checklists12 pm: 6.1% of 72581 checklists1 pm: 6.3% of 71478 checklists2 pm: 6.6% of 69994 checklists3 pm: 6.2% of 66822 checklists4 pm: 4.7% of 55950 checklists5 pm: 2.0% of 41360 checklists6 pm: 1.1% 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
January14%14%14%13%
February13%12%11%14%
March13%11%7.8%5.6%
April3.8%2.2%1.2%0.7%
May0.4%0.3%0.2%0.3%
June0.3%0.3%0.2%0.2%
July0.2%0.2%0.1%0.1%
August0.2%0.1%0.2%0.1%
September0.2%0.1%0.1%0.1%
October0.1%0.2%0.3%1.5%
November4.5%7.9%10%12%
December14%13%12%12%

Neighboring states

  • Delaware: arrives early November, 1 week later than New Jersey
  • Connecticut: arrives mid October, 1 week earlier than New Jersey
  • Pennsylvania: arrives late October, in the same week than New Jersey
  • New York: arrives mid October, 1 week earlier than New Jersey

Common questions

When do Hooded Mergansers arrive in New Jersey?
Hooded Mergansers are winter birds in New Jersey: the first arrive in late October, they are common by the second week of November, peak in the second week of January (14% of checklists), and most are gone by mid March.
When do Hooded Mergansers leave New Jersey?
Most Hooded Mergansers have left New Jersey by mid March, when reports fall below half their usual rate. Stragglers are still reported until mid April.
When is the best time to see a Hooded Merganser in New Jersey?
The Hooded Merganser is reported most often in the second week of January, on about 14% of New Jersey checklists.
Where in New Jersey are Hooded Mergansers seen most often?
By county, Passaic County, Atlantic County, and Morris County have the highest peak reporting rates for the Hooded Merganser (counties with at least 200 checklists).