WhenToBird

Nannopterum auritum · Phalacrocoracidae

When Do Double-crested Cormorants Arrive in Michigan?

Adult Double-crested Cormorant
Photo: jubileej, CC0 1.0 via iNaturalist

Double-crested Cormorants reach Michigan in mid March, are common by early April, peak in early September (15% of checklists), and most are gone by early November.

When to look

First arrivalsMar 15-21mid March
Common byApr 1-7early April
PeakSep 1-7early September
Most gone byNov 1-7early November

Best: early September. First arrivals mid March; most are gone by early November. Peak: on about 15% of Michigan checklists.

  1. Janrare
  2. Febnot usually seen
  3. Maruncommon
  4. Aprcommon
  5. Maycommon
  6. Juncommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novcommon
  12. Decrare

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

0%5%10%15%20%Jan 1-7: 0.8% of 38160 checklistsJan 8-14: 0.6% of 24696 checklistsJan 15-21: 0.4% of 23771 checklistsJan 22-31: 0.4% of 31347 checklistsFeb 1-7: 0.3% of 23225 checklistsFeb 8-14: 0.4% of 27398 checklistsFeb 15-21: 0.2% of 36606 checklistsFeb 22-28: 0.4% of 27127 checklistsMar 1-7: 0.4% of 29700 checklistsMar 8-14: 0.5% of 31587 checklistsMar 15-21: 1.1% of 32118 checklistsMar 22-31: 2.4% of 47777 checklistsApr 1-7: 4.4% of 38557 checklistsApr 8-14: 6.8% of 42207 checklistsApr 15-21: 9.1% of 42759 checklistsApr 22-30: 10% of 64458 checklistsMay 1-7: 9.3% of 60998 checklistsMay 8-14: 8.4% of 72091 checklistsMay 15-21: 9.3% of 59058 checklistsMay 22-31: 7.5% of 64724 checklistsJun 1-7: 5.6% of 35990 checklistsJun 8-14: 4.8% of 32595 checklistsJun 15-21: 4.4% of 30017 checklistsJun 22-30: 4.8% of 33988 checklistsJul 1-7: 5.3% of 28708 checklistsJul 8-14: 5.4% of 25175 checklistsJul 15-21: 6.7% of 24084 checklistsJul 22-31: 7.9% of 33522 checklistsAug 1-7: 9.9% of 25098 checklistsAug 8-14: 12% of 24353 checklistsAug 15-21: 14% of 25059 checklistsAug 22-31: 15% of 37489 checklistsSep 1-7: 15% of 28410 checklistsSep 8-14: 14% of 27887 checklistsSep 15-21: 14% of 26614 checklistsSep 22-30: 13% of 32557 checklistsOct 1-7: 12% of 25844 checklistsOct 8-14: 12% of 27741 checklistsOct 15-21: 11% of 24693 checklistsOct 22-31: 8.6% of 32460 checklistsNov 1-7: 6.3% of 23660 checklistsNov 8-14: 3.5% of 21542 checklistsNov 15-21: 2.5% of 19922 checklistsNov 22-30: 1.6% of 25069 checklistsDec 1-7: 1.2% of 18272 checklistsDec 8-14: 0.9% of 18961 checklistsDec 15-21: 0.7% of 24171 checklistsDec 22-31: 0.6% 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. Monroe CountyBest mid August · 609 checklists that week, 22,078 in all57%
  2. Mackinac CountyBest the second week of September · 228 checklists that week, 7,988 in all53%
  3. Delta CountyBest early May · 249 checklists that week, 6,537 in all49%
  4. Gratiot CountyBest the second week of August · 155 checklists that week, 5,892 in all44%
  5. Bay CountyBest late April · 743 checklists that week, 16,522 in all40%
  6. Alpena CountyBest late April · 108 checklists that week, 3,793 in all38%

Best spots

Share of checklists at the peak
  1. Genessee Recreation AreaGenesee County, best late August · 45 checklists that week, 392 in all99%
  2. Lighthouse ParkSt. Clair County, best late September · 61 checklists that week, 1,206 in all96%
  3. Harbor ParkAlcona County, best the second week of August · 30 checklists that week, 1,441 in all94%
  4. Overlook ParkMidland County, best late August · 61 checklists that week, 2,020 in all94%

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

Best time of day

In Michigan, the Double-crested Cormorant is most often listed on checklists started between 6 and 8 am (8.3% of those checklists).

0%5%10%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: 8.7% of 39298 checklists7 am: 8.2% of 120344 checklists8 am: 6.9% of 180109 checklists9 am: 6.4% of 171966 checklists10 am: 6.3% of 156332 checklists11 am: 6.1% of 134964 checklists12 pm: 6.1% of 120967 checklists1 pm: 6.4% of 113852 checklists2 pm: 5.9% of 110773 checklists3 pm: 5.7% of 105530 checklists4 pm: 5.9% of 100958 checklists5 pm: 6.3% of 80085 checklists6 pm: 6.6% of 62883 checklists7 pm: 4.9% 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
January0.8%0.6%0.4%0.4%
February0.3%0.4%0.2%0.4%
March0.4%0.5%1.1%2.4%
April4.4%6.8%9.1%10%
May9.3%8.4%9.3%7.5%
June5.6%4.8%4.4%4.8%
July5.3%5.4%6.7%7.9%
August9.9%12%14%15%
September15%14%14%13%
October12%12%11%8.6%
November6.3%3.5%2.5%1.6%
December1.2%0.9%0.7%0.6%

Neighboring states

  • Ohio: arrives late February, 3 weeks earlier than Michigan
  • Indiana: arrives late February, 3 weeks earlier than Michigan
  • Illinois: arrives early March, 2 weeks earlier than Michigan
  • Wisconsin: arrives late March, 1 week later than Michigan

Common questions

When do Double-crested Cormorants arrive in Michigan?
Double-crested Cormorants reach Michigan in mid March, are common by early April, peak in early September (15% of checklists), and most are gone by early November.
When do Double-crested Cormorants leave Michigan?
Most Double-crested Cormorants have left Michigan by early November, when reports fall below half their usual rate. Stragglers are still reported until early December.
When is the best time to see a Double-crested Cormorant in Michigan?
The Double-crested Cormorant is reported most often in early September, on about 15% of Michigan checklists.
Where in Michigan are Double-crested Cormorants seen most often?
By county, Monroe County, Mackinac County, and Delta County have the highest peak reporting rates for the Double-crested Cormorant (counties with at least 200 checklists).