WhenToBird

Mergus serrator · Anatidae

When Do Red-breasted Mergansers Arrive in New York?

Adult male Red-breasted Merganser
Photo: Peter Chen 2.0, CC BY 4.0 via iNaturalist

Red-breasted Mergansers are winter birds in New York: the first arrive in mid October, they are common by the second week of November, peak in late January (12% of checklists), and most are gone by mid April.

When to look

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

Best: late January. First arrivals mid October; most are gone by mid April. Peak: on about 12% of New York checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprcommon
  5. Mayuncommon
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octuncommon
  11. Novcommon
  12. Decpeak season

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

0%5%10%15%Jan 1-7: 9.8% of 66410 checklistsJan 8-14: 11% of 49310 checklistsJan 15-21: 12% of 49919 checklistsJan 22-31: 11% of 62513 checklistsFeb 1-7: 11% of 43526 checklistsFeb 8-14: 9.8% of 49753 checklistsFeb 15-21: 8.0% of 65147 checklistsFeb 22-28: 10% of 50173 checklistsMar 1-7: 9.1% of 50325 checklistsMar 8-14: 8.2% of 55371 checklistsMar 15-21: 7.8% of 56293 checklistsMar 22-31: 8.3% of 82677 checklistsApr 1-7: 7.7% of 65295 checklistsApr 8-14: 7.1% of 73080 checklistsApr 15-21: 5.6% of 73857 checklistsApr 22-30: 3.7% of 106093 checklistsMay 1-7: 2.4% of 102772 checklistsMay 8-14: 1.6% of 110051 checklistsMay 15-21: 1.1% of 94797 checklistsMay 22-31: 0.6% of 101272 checklistsJun 1-7: 0.3% of 59471 checklistsJun 8-14: 0.2% of 55497 checklistsJun 15-21: 0.1% of 51761 checklistsJun 22-30: 0.1% of 59219 checklistsJul 1-7: 0.1% of 48226 checklistsJul 8-14: 0.1% of 42315 checklistsJul 15-21: 0.1% of 40637 checklistsJul 22-31: 0.2% of 57183 checklistsAug 1-7: 0.2% of 40461 checklistsAug 8-14: 0.1% of 39880 checklistsAug 15-21: 0.1% of 41146 checklistsAug 22-31: 0.1% of 63381 checklistsSep 1-7: 0.1% of 48640 checklistsSep 8-14: 0.2% of 47882 checklistsSep 15-21: 0.2% of 49063 checklistsSep 22-30: 0.3% of 57906 checklistsOct 1-7: 0.5% of 48447 checklistsOct 8-14: 0.9% of 51901 checklistsOct 15-21: 1.3% of 46717 checklistsOct 22-31: 2.2% of 61992 checklistsNov 1-7: 3.6% of 44593 checklistsNov 8-14: 4.9% of 42566 checklistsNov 15-21: 6.7% of 39675 checklistsNov 22-30: 8.6% of 51197 checklistsDec 1-7: 8.5% of 36567 checklistsDec 8-14: 7.9% of 37254 checklistsDec 15-21: 8.8% of 43754 checklistsDec 22-31: 10% of 62470 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 York 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 York

Best counties

Share of checklists at the peak
  1. Wayne CountyBest early December · 518 checklists that week, 37,738 in all38%
  2. Bronx CountyBest late January · 612 checklists that week, 24,489 in all36%
  3. Niagara CountyBest late November · 704 checklists that week, 28,936 in all33%
  4. Kings CountyBest late January · 3096 checklists that week, 134,897 in all32%
  5. Oswego CountyBest late November · 688 checklists that week, 39,208 in all29%
  6. Nassau CountyBest late January · 2497 checklists that week, 95,019 in all26%

Best spots

Share of checklists at the peak
  1. Twin IslandBronx County, best mid January · 27 checklists that week, 553 in all99%
  2. Hamlin Beach State Park (west)Monroe County, best late November · 24 checklists that week, 382 in all99%
  3. Town of Ontario LandWayne County, best late January · 40 checklists that week, 843 in all98%
  4. Sage CreekOswego County, best mid November · 45 checklists that week, 2,124 in all96%
  5. Hamlin Beach State ParkMonroe County, best the second week of November · 67 checklists that week, 2,133 in all96%

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

Best time of day

In New York, the Red-breasted Merganser is most often listed on checklists started between 1 and 3 pm (5.8% of those checklists).

0%2%4%6%12 am: too few checklists (1146) to judge1 am: too few checklists (1055) to judge2 am: too few checklists (1121) to judge3 am: too few checklists (1353) to judge4 am: too few checklists (4785) to judge5 am: too few checklists (32052) to judge6 am: 2.5% of 124869 checklists7 am: 3.2% of 298506 checklists8 am: 3.9% of 337334 checklists9 am: 4.7% of 307787 checklists10 am: 5.2% of 270801 checklists11 am: 5.7% of 233238 checklists12 pm: 5.6% of 213830 checklists1 pm: 5.9% of 193321 checklists2 pm: 5.6% of 180741 checklists3 pm: 5.0% of 170348 checklists4 pm: 3.9% of 147224 checklists5 pm: 2.1% of 111962 checklists6 pm: 1.7% of 78261 checklists7 pm: too few checklists (44425) to judge8 pm: too few checklists (15648) to judge9 pm: too few checklists (4795) to judge10 pm: too few checklists (2454) to judge11 pm: too few checklists (1378) 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
January9.8%11%12%11%
February11%9.8%8.0%10%
March9.1%8.2%7.8%8.3%
April7.7%7.1%5.6%3.7%
May2.4%1.6%1.1%0.6%
June0.3%0.2%0.1%0.1%
July0.1%0.1%0.1%0.2%
August0.2%0.1%0.1%0.1%
September0.1%0.2%0.2%0.3%
October0.5%0.9%1.3%2.2%
November3.6%4.9%6.7%8.6%
December8.5%7.9%8.8%10%

Neighboring states

  • Connecticut: arrives late October, 1 week later than New York
  • New Jersey: arrives early November, 2 weeks later than New York
  • Pennsylvania: arrives early November, 2 weeks later than New York
  • Vermont: arrives mid October, in the same week than New York

Common questions

When do Red-breasted Mergansers arrive in New York?
Red-breasted Mergansers are winter birds in New York: the first arrive in mid October, they are common by the second week of November, peak in late January (12% of checklists), and most are gone by mid April.
When do Red-breasted Mergansers leave New York?
Most Red-breasted Mergansers have left New York by mid April, when reports fall below half their usual rate. Stragglers are still reported until mid May.
When is the best time to see a Red-breasted Merganser in New York?
The Red-breasted Merganser is reported most often in late January, on about 12% of New York checklists.
Where in New York are Red-breasted Mergansers seen most often?
By county, Wayne County, Bronx County, and Niagara County have the highest peak reporting rates for the Red-breasted Merganser (counties with at least 200 checklists).