WhenToBird

Mergus serrator · Anatidae

When Do Red-breasted Mergansers Arrive in Michigan?

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

Red-breasted Mergansers reach Michigan in late September, are common by mid October, peak in early April (7.9% of checklists), and most are gone by late May.

When to look

First arrivalsSep 22-30late September
Common byOct 15-21mid October
PeakApr 1-7early April
Most gone byMay 22-31late May

Best: early April. First arrivals late September; most are gone by late May. Peak: on about 7.9% of Michigan checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maycommon
  6. Jununcommon
  7. Julrare
  8. Augrare
  9. Seprare
  10. Octcommon
  11. Novpeak season
  12. Decpeak season

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

0%5%10%Jan 1-7: 4.9% of 38160 checklistsJan 8-14: 5.0% of 24696 checklistsJan 15-21: 4.7% of 23771 checklistsJan 22-31: 4.6% of 31347 checklistsFeb 1-7: 4.4% of 23225 checklistsFeb 8-14: 3.2% of 27398 checklistsFeb 15-21: 2.4% of 36606 checklistsFeb 22-28: 4.4% of 27127 checklistsMar 1-7: 6.1% of 29700 checklistsMar 8-14: 5.5% of 31587 checklistsMar 15-21: 5.9% of 32118 checklistsMar 22-31: 8.0% of 47777 checklistsApr 1-7: 8.5% of 38557 checklistsApr 8-14: 7.4% of 42207 checklistsApr 15-21: 6.8% of 42759 checklistsApr 22-30: 5.1% of 64458 checklistsMay 1-7: 3.3% of 60998 checklistsMay 8-14: 2.6% of 72091 checklistsMay 15-21: 3.6% of 59058 checklistsMay 22-31: 2.5% of 64724 checklistsJun 1-7: 1.3% of 35990 checklistsJun 8-14: 1.0% of 32595 checklistsJun 15-21: 0.8% of 30017 checklistsJun 22-30: 0.6% of 33988 checklistsJul 1-7: 0.5% of 28708 checklistsJul 8-14: 0.5% of 25175 checklistsJul 15-21: 0.4% of 24084 checklistsJul 22-31: 0.5% of 33522 checklistsAug 1-7: 0.6% of 25098 checklistsAug 8-14: 0.4% of 24353 checklistsAug 15-21: 0.5% of 25059 checklistsAug 22-31: 0.4% of 37489 checklistsSep 1-7: 0.4% of 28410 checklistsSep 8-14: 0.7% of 27887 checklistsSep 15-21: 0.7% of 26614 checklistsSep 22-30: 1.1% of 32557 checklistsOct 1-7: 1.3% of 25844 checklistsOct 8-14: 2.1% of 27741 checklistsOct 15-21: 2.6% of 24693 checklistsOct 22-31: 3.7% of 32460 checklistsNov 1-7: 4.7% of 23660 checklistsNov 8-14: 5.8% of 21542 checklistsNov 15-21: 6.5% of 19922 checklistsNov 22-30: 7.1% of 25069 checklistsDec 1-7: 6.5% of 18272 checklistsDec 8-14: 5.1% of 18961 checklistsDec 15-21: 4.7% of 24171 checklistsDec 22-31: 5.6% 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. Sanilac CountyBest late November · 99 checklists that week, 4,539 in all55%
  2. Huron CountyBest mid November · 121 checklists that week, 4,733 in all42%
  3. Mackinac CountyBest late April · 175 checklists that week, 7,988 in all42%
  4. Alcona CountyBest late November · 192 checklists that week, 9,236 in all41%
  5. Delta CountyBest early November · 139 checklists that week, 6,537 in all39%
  6. Iosco CountyBest mid November · 354 checklists that week, 31,409 in all37%

Best spots

Share of checklists at the peak
  1. Conkling Heritage ParkCheboygan County, best late April · 31 checklists that week, 359 in all98%
  2. Holland State Park (Ottawa Beach)Ottawa County, best early April · 52 checklists that week, 4,726 in all95%
  3. Pere Marquette River (Ludington)Mason County, best late April · 20 checklists that week, 423 in all94%
  4. Pere Marquette RiverMason County, best the second week of December · 24 checklists that week, 578 in all94%
  5. Tierney ParkSanilac County, best late November · 21 checklists that week, 402 in all93%
  6. Douglas Beach ParkAllegan County, best the second week of November · 24 checklists that week, 358 in all92%

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

Best time of day

In Michigan, the Red-breasted Merganser is most often listed on checklists started between 12 and 2 pm (4.0% of those checklists).

0%2%4%6%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: 2.8% of 39298 checklists7 am: 3.2% of 120344 checklists8 am: 3.5% of 180109 checklists9 am: 3.7% of 171966 checklists10 am: 3.8% of 156332 checklists11 am: 4.0% of 134964 checklists12 pm: 4.0% of 120967 checklists1 pm: 4.1% of 113852 checklists2 pm: 3.9% of 110773 checklists3 pm: 3.8% of 105530 checklists4 pm: 3.4% of 100958 checklists5 pm: 2.7% of 80085 checklists6 pm: 2.6% of 62883 checklists7 pm: 2.1% 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
January4.9%5.0%4.7%4.6%
February4.4%3.2%2.4%4.4%
March6.1%5.5%5.9%8.0%
April8.5%7.4%6.8%5.1%
May3.3%2.6%3.6%2.5%
June1.3%1.0%0.8%0.6%
July0.5%0.5%0.4%0.5%
August0.6%0.4%0.5%0.4%
September0.4%0.7%0.7%1.1%
October1.3%2.1%2.6%3.7%
November4.7%5.8%6.5%7.1%
December6.5%5.1%4.7%5.6%

Neighboring states

  • Ohio: arrives late October, 4 weeks later than Michigan
  • Indiana: arrives early November, 5 weeks later than Michigan
  • Illinois: arrives late October, 4 weeks later than Michigan
  • Wisconsin: arrives mid October, 3 weeks later than Michigan

Common questions

When do Red-breasted Mergansers arrive in Michigan?
Red-breasted Mergansers reach Michigan in late September, are common by mid October, peak in early April (7.9% of checklists), and most are gone by late May.
When do Red-breasted Mergansers leave Michigan?
Most Red-breasted Mergansers have left Michigan by late May, 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 Red-breasted Merganser in Michigan?
The Red-breasted Merganser is reported most often in early April, on about 7.9% of Michigan checklists.
Where in Michigan are Red-breasted Mergansers seen most often?
By county, Sanilac County, Huron County, and Mackinac County have the highest peak reporting rates for the Red-breasted Merganser (counties with at least 200 checklists).