WhenToBird

Mergus merganser · Anatidae

When Do Common Mergansers Arrive in Michigan?

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

Common Mergansers are winter birds in Michigan: the first arrive in the second week of September, they are common by mid November, peak in the second week of March (15% of checklists), and most are gone by late April.

When to look

First arrivalsSep 8-14the second week of September
Common byNov 15-21mid November
PeakMar 8-14the second week of March
Most gone byApr 22-30late April

Best: the second week of March. First arrivals the second week of September; most are gone by late April. Peak: on about 15% of Michigan checklists.

  1. Jancommon
  2. Febpeak season
  3. Marpeak season
  4. Aprpeak season
  5. Mayuncommon
  6. Jununcommon
  7. Julrare
  8. Augrare
  9. Sepuncommon
  10. Octuncommon
  11. Novcommon
  12. Deccommon

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

0%5%10%15%20%Jan 1-7: 9.6% of 38160 checklistsJan 8-14: 9.3% of 24696 checklistsJan 15-21: 8.6% of 23771 checklistsJan 22-31: 8.8% of 31347 checklistsFeb 1-7: 9.0% of 23225 checklistsFeb 8-14: 8.8% of 27398 checklistsFeb 15-21: 7.9% of 36606 checklistsFeb 22-28: 13% of 27127 checklistsMar 1-7: 15% of 29700 checklistsMar 8-14: 16% of 31587 checklistsMar 15-21: 15% of 32118 checklistsMar 22-31: 15% of 47777 checklistsApr 1-7: 13% of 38557 checklistsApr 8-14: 9.7% of 42207 checklistsApr 15-21: 7.5% of 42759 checklistsApr 22-30: 5.5% of 64458 checklistsMay 1-7: 3.8% of 60998 checklistsMay 8-14: 3.4% of 72091 checklistsMay 15-21: 4.8% of 59058 checklistsMay 22-31: 4.4% of 64724 checklistsJun 1-7: 3.3% of 35990 checklistsJun 8-14: 2.6% of 32595 checklistsJun 15-21: 2.1% of 30017 checklistsJun 22-30: 2.1% of 33988 checklistsJul 1-7: 2.1% of 28708 checklistsJul 8-14: 1.9% of 25175 checklistsJul 15-21: 2.1% of 24084 checklistsJul 22-31: 1.8% of 33522 checklistsAug 1-7: 1.8% of 25098 checklistsAug 8-14: 1.9% of 24353 checklistsAug 15-21: 1.8% of 25059 checklistsAug 22-31: 2.1% of 37489 checklistsSep 1-7: 2.3% of 28410 checklistsSep 8-14: 2.7% of 27887 checklistsSep 15-21: 2.8% of 26614 checklistsSep 22-30: 2.8% of 32557 checklistsOct 1-7: 2.6% of 25844 checklistsOct 8-14: 2.8% of 27741 checklistsOct 15-21: 3.0% of 24693 checklistsOct 22-31: 3.7% of 32460 checklistsNov 1-7: 3.9% of 23660 checklistsNov 8-14: 5.4% of 21542 checklistsNov 15-21: 6.5% of 19922 checklistsNov 22-30: 7.4% of 25069 checklistsDec 1-7: 8.5% of 18272 checklistsDec 8-14: 8.6% of 18961 checklistsDec 15-21: 8.2% of 24171 checklistsDec 22-31: 8.2% of 30908 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 Michigan 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 Michigan

Best counties

Share of checklists at the peak
  1. Emmet CountyBest the second week of December · 98 checklists that week, 11,769 in all46%
  2. Gratiot CountyBest late March · 237 checklists that week, 5,892 in all46%
  3. Kalkaska CountyBest early March · 62 checklists that week, 5,833 in all43%
  4. Ontonagon CountyBest early April · 37 checklists that week, 3,548 in all43%
  5. Arenac CountyBest early April · 70 checklists that week, 4,464 in all42%
  6. Alpena CountyBest late March · 102 checklists that week, 3,793 in all42%

Best spots

Share of checklists at the peak
  1. City of Flint ParkGenesee County, best late February · 22 checklists that week, 248 in all100%
  2. Rugg Pond Natural AreaKalkaska County, best late February · 42 checklists that week, 844 in all98%
  3. Lake AlleganAllegan County, best the second week of January · 64 checklists that week, 208 in all97%
  4. Thompson LakeLivingston County, best the second week of March · 28 checklists that week, 439 in all97%
  5. R A Greene ParkJackson County, best late July · 23 checklists that week, 103 in all96%

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

Best time of day

In Michigan, the Common Merganser is most often listed on checklists started between 1 and 3 pm (7.4% of those checklists).

0%2%4%6%8%12 am: too few checklists (712) to judge1 am: too few checklists (592) to judge2 am: too few checklists (532) to judge3 am: too few checklists (516) to judge4 am: too few checklists (1592) to judge5 am: too few checklists (6849) to judge6 am: 5.0% of 39298 checklists7 am: 5.3% of 120344 checklists8 am: 5.6% of 180109 checklists9 am: 6.1% of 171966 checklists10 am: 6.6% of 156332 checklists11 am: 6.9% of 134964 checklists12 pm: 7.1% of 120967 checklists1 pm: 7.5% of 113852 checklists2 pm: 7.3% of 110773 checklists3 pm: 7.1% of 105530 checklists4 pm: 6.6% of 100958 checklists5 pm: 5.1% of 80085 checklists6 pm: 4.1% of 62883 checklists7 pm: 3.4% of 44912 checklists8 pm: too few checklists (21062) to judge9 pm: too few checklists (5920) to judge10 pm: too few checklists (1629) to judge11 pm: too few checklists (775) 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
January9.6%9.3%8.6%8.8%
February9.0%8.8%7.9%13%
March15%16%15%15%
April13%9.7%7.5%5.5%
May3.8%3.4%4.8%4.4%
June3.3%2.6%2.1%2.1%
July2.1%1.9%2.1%1.8%
August1.8%1.9%1.8%2.1%
September2.3%2.7%2.8%2.8%
October2.6%2.8%3.0%3.7%
November3.9%5.4%6.5%7.4%
December8.5%8.6%8.2%8.2%

Neighboring states

  • Ohio: arrives late October, 6 weeks later than Michigan
  • Indiana: arrives late November, 10 weeks later than Michigan
  • Illinois: arrives the second week of November, 8 weeks later than Michigan
  • Wisconsin: arrives mid September, 1 week later than Michigan

Common questions

When do Common Mergansers arrive in Michigan?
Common Mergansers are winter birds in Michigan: the first arrive in the second week of September, they are common by mid November, peak in the second week of March (15% of checklists), and most are gone by late April.
When do Common Mergansers leave Michigan?
Most Common Mergansers have left Michigan by late April, when reports fall below half their usual rate. Stragglers are still reported until the second week of June.
When is the best time to see a Common Merganser in Michigan?
The Common Merganser is reported most often in the second week of March, on about 15% of Michigan checklists.
Where in Michigan are Common Mergansers seen most often?
By county, Emmet County, Gratiot County, and Kalkaska County have the highest peak reporting rates for the Common Merganser (counties with at least 200 checklists).