WhenToBird

Mergus merganser · Anatidae

When Do Common Mergansers Arrive in Rhode Island?

Adult female Common Merganser
Photo: Christoph Moning, CC BY 4.0 via iNaturalist

Common Mergansers are winter birds in Rhode Island: the first arrive in the second week of November, they are common by early December, peak in early March (8.8% of checklists), and most are gone by early April.

When to look

First arrivalsNov 8-14the second week of November
Common byDec 1-7early December
PeakMar 1-7early March
Most gone byApr 1-7early April

Best: early March. First arrivals the second week of November; most are gone by early April. Peak: on about 8.8% of Rhode Island checklists.

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

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

0%5%10%Jan 1-7: 6.3% of 5678 checklistsJan 8-14: 7.8% of 4004 checklistsJan 15-21: 7.2% of 3691 checklistsJan 22-31: 8.1% of 4738 checklistsFeb 1-7: 8.6% of 3178 checklistsFeb 8-14: 7.7% of 3262 checklistsFeb 15-21: 7.3% of 4286 checklistsFeb 22-28: 8.7% of 3449 checklistsMar 1-7: 9.5% of 3014 checklistsMar 8-14: 8.3% of 3259 checklistsMar 15-21: 6.9% of 3320 checklistsMar 22-31: 5.7% of 4692 checklistsApr 1-7: 4.0% of 3280 checklistsApr 8-14: 2.7% of 3872 checklistsApr 15-21: 1.7% of 4037 checklistsApr 22-30: 0.7% of 5595 checklistsMay 1-7: 0.3% of 5699 checklistsMay 8-14: 0.1% of 6089 checklistsMay 15-21: 0.1% of 4937 checklistsMay 22-31: 0% of 5445 checklistsJun 1-7: 0% of 3031 checklistsJun 8-14: 0.1% of 2793 checklistsJun 15-21: 0.1% of 2736 checklistsJun 22-30: 0.2% of 3318 checklistsJul 1-7: 0.2% of 2629 checklistsJul 8-14: 0% of 2561 checklistsJul 15-21: 0.1% of 2580 checklistsJul 22-31: 0.1% of 3654 checklistsAug 1-7: 0.1% of 2629 checklistsAug 8-14: 0% of 2912 checklistsAug 15-21: 0% of 2850 checklistsAug 22-31: 0.1% of 4007 checklistsSep 1-7: 0.1% of 2893 checklistsSep 8-14: 0% of 2850 checklistsSep 15-21: 0% of 2770 checklistsSep 22-30: 0.1% of 3888 checklistsOct 1-7: 0.1% of 3174 checklistsOct 8-14: 0.1% of 3278 checklistsOct 15-21: 0.2% of 3008 checklistsOct 22-31: 0.3% of 3678 checklistsNov 1-7: 0.6% of 3270 checklistsNov 8-14: 1.1% of 3405 checklistsNov 15-21: 2.3% of 2907 checklistsNov 22-30: 3.4% of 3607 checklistsDec 1-7: 4.8% of 2415 checklistsDec 8-14: 5.9% of 2345 checklistsDec 15-21: 6.5% of 2836 checklistsDec 22-31: 6.7% of 4826 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 Rhode Island 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 Rhode Island

Best counties

Share of checklists at the peak
  1. Providence CountyBest the second week of January · 803 checklists that week, 40,898 in all14%
  2. Bristol CountyBest the second week of March · 285 checklists that week, 15,899 in all9.3%
  3. Kent CountyBest late November · 379 checklists that week, 16,966 in all9.1%
  4. Newport CountyBest late February · 864 checklists that week, 33,574 in all8.4%
  5. Washington CountyBest early March · 1055 checklists that week, 65,038 in all8.1%

Best spots

Share of checklists at the peak
  1. James V Turner ReservoirProvidence County, best the second week of January · 35 checklists that week, 420 in all84%
  2. Mashapaug PondProvidence County, best mid December · 42 checklists that week, 260 in all69%
  3. Tiogue Lake (Saw Mill Hill)Kent County, best the second week of February · 23 checklists that week, 236 in all67%
  4. Tiogue LakeKent County, best late November · 48 checklists that week, 252 in all66%
  5. Lawton Valley ReservoirNewport County, best early February · 20 checklists that week, 236 in all61%
  6. Easton PondNewport County, best mid February · 33 checklists that week, 983 in all58%

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

Best time of day

In Rhode Island, the Common Merganser is most often listed on checklists started between 1 and 3 pm (3.7% of those checklists).

0%1%2%3%4%12 am: too few checklists (42) to judge1 am: too few checklists (58) to judge2 am: too few checklists (45) to judge3 am: too few checklists (69) to judge4 am: too few checklists (319) to judge5 am: too few checklists (3170) to judge6 am: 1.6% of 10493 checklists7 am: 2.6% of 17631 checklists8 am: 2.8% of 18834 checklists9 am: 2.8% of 17725 checklists10 am: 2.9% of 16696 checklists11 am: 3.8% of 14799 checklists12 pm: 3.6% of 12580 checklists1 pm: 3.8% of 12779 checklists2 pm: 3.7% of 12302 checklists3 pm: 3.7% of 11884 checklists4 pm: 2.8% of 9762 checklists5 pm: 1.1% of 6442 checklists6 pm: 0.8% of 3947 checklists7 pm: too few checklists (2119) to judge8 pm: too few checklists (452) to judge9 pm: too few checklists (105) to judge10 pm: too few checklists (69) to judge11 pm: too few checklists (53) 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
January6.3%7.8%7.2%8.1%
February8.6%7.7%7.3%8.7%
March9.5%8.3%6.9%5.7%
April4.0%2.7%1.7%0.7%
May0.3%0.1%0.1%0%
June0%0.1%0.1%0.2%
July0.2%0%0.1%0.1%
August0.1%0%0%0.1%
September0.1%0%0%0.1%
October0.1%0.1%0.2%0.3%
November0.6%1.1%2.3%3.4%
December4.8%5.9%6.5%6.7%

Neighboring states

  • Massachusetts: arrives mid October, 3 weeks earlier than Rhode Island
  • Connecticut: arrives mid October, 3 weeks earlier than Rhode Island
  • New Hampshire: arrives late September, 6 weeks earlier than Rhode Island
  • Vermont: arrives late July, 14 weeks earlier than Rhode Island

Common questions

When do Common Mergansers arrive in Rhode Island?
Common Mergansers are winter birds in Rhode Island: the first arrive in the second week of November, they are common by early December, peak in early March (8.8% of checklists), and most are gone by early April.
When do Common Mergansers leave Rhode Island?
Most Common Mergansers have left Rhode Island by early April, when reports fall below half their usual rate. Stragglers are still reported until mid April.
When is the best time to see a Common Merganser in Rhode Island?
The Common Merganser is reported most often in early March, on about 8.8% of Rhode Island checklists.
Where in Rhode Island are Common Mergansers seen most often?
By county, Providence County, Bristol County, and Kent County have the highest peak reporting rates for the Common Merganser (counties with at least 200 checklists).