WhenToBird

Lophodytes cucullatus · Anatidae

When Do Hooded Mergansers Arrive in Wisconsin?

Adult male Hooded Merganser
Photo: Justin Flint, CC BY 4.0 via iNaturalist

Hooded Mergansers are winter birds in Wisconsin: the first arrive in mid February, they are common by late February, peak in late March (13% of checklists), and most are gone by early January.

When to look

First arrivalsFeb 15-21mid February
Common byFeb 22-28late February
PeakMar 22-31late March
Most gone byJan 1-7early January

Best: late March. First arrivals mid February; most are gone by early January. Peak: on about 13% of Wisconsin checklists.

  1. Janrare
  2. Febuncommon
  3. Marpeak season
  4. Aprpeak season
  5. Mayuncommon
  6. Jununcommon
  7. Juluncommon
  8. Auguncommon
  9. Seprare
  10. Octuncommon
  11. Novcommon
  12. Decuncommon

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

0%5%10%15%Jan 1-7: 2.2% of 27925 checklistsJan 8-14: 1.6% of 18337 checklistsJan 15-21: 1.2% of 17370 checklistsJan 22-31: 1.4% of 23777 checklistsFeb 1-7: 1.3% of 16656 checklistsFeb 8-14: 1.2% of 18286 checklistsFeb 15-21: 1.4% of 24739 checklistsFeb 22-28: 3.1% of 20113 checklistsMar 1-7: 7.4% of 24024 checklistsMar 8-14: 11% of 26722 checklistsMar 15-21: 13% of 27238 checklistsMar 22-31: 13% of 40171 checklistsApr 1-7: 12% of 34961 checklistsApr 8-14: 8.8% of 39128 checklistsApr 15-21: 7.4% of 38887 checklistsApr 22-30: 5.5% of 57231 checklistsMay 1-7: 3.5% of 55115 checklistsMay 8-14: 2.5% of 63098 checklistsMay 15-21: 2.6% of 49821 checklistsMay 22-31: 2.5% of 56796 checklistsJun 1-7: 2.2% of 33621 checklistsJun 8-14: 2.1% of 31282 checklistsJun 15-21: 1.9% of 30186 checklistsJun 22-30: 1.9% of 35128 checklistsJul 1-7: 2.1% of 27088 checklistsJul 8-14: 2.1% of 23293 checklistsJul 15-21: 2.3% of 20933 checklistsJul 22-31: 2.3% of 27595 checklistsAug 1-7: 2.3% of 19147 checklistsAug 8-14: 2.0% of 18286 checklistsAug 15-21: 2.2% of 19195 checklistsAug 22-31: 1.7% of 28229 checklistsSep 1-7: 1.6% of 22408 checklistsSep 8-14: 1.5% of 20857 checklistsSep 15-21: 1.5% of 20707 checklistsSep 22-30: 1.5% of 26469 checklistsOct 1-7: 1.6% of 21069 checklistsOct 8-14: 1.3% of 21011 checklistsOct 15-21: 2.1% of 20006 checklistsOct 22-31: 3.5% of 26362 checklistsNov 1-7: 6.4% of 18928 checklistsNov 8-14: 7.1% of 17052 checklistsNov 15-21: 6.9% of 16291 checklistsNov 22-30: 6.4% of 20564 checklistsDec 1-7: 4.6% of 15354 checklistsDec 8-14: 3.5% of 16294 checklistsDec 15-21: 2.2% of 21430 checklistsDec 22-31: 1.9% of 26314 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 Wisconsin 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 Wisconsin

Best counties

Share of checklists at the peak
  1. Lincoln CountyBest early April · 225 checklists that week, 8,013 in all37%
  2. Sawyer CountyBest the second week of April · 153 checklists that week, 7,502 in all29%
  3. Price CountyBest the second week of April · 178 checklists that week, 5,795 in all28%
  4. Menominee CountyBest early April · 14 checklists that week, 745 in all26%
  5. Burnett CountyBest late March · 288 checklists that week, 11,034 in all26%
  6. Washburn CountyBest the second week of April · 131 checklists that week, 7,099 in all25%

Best spots

Share of checklists at the peak
  1. Sunset ParkDoor County, best late October · 43 checklists that week, 441 in all91%
  2. Turvilles BayDane County, best the second week of December · 27 checklists that week, 204 in all88%
  3. Dead Horse BayBrown County, best early March · 22 checklists that week, 630 in all86%
  4. Mack Wildlife Area (north)Outagamie County, best late March · 34 checklists that week, 451 in all74%
  5. Manitowoc Small Boat HarborManitowoc County, best the second week of July · 55 checklists that week, 2,200 in all73%
  6. Lake BarneyDane County, best the second week of March · 21 checklists that week, 864 in all71%

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

Best time of day

In Wisconsin, the Hooded Merganser is most often listed on checklists started between 1 and 3 pm (4.5% of those checklists).

0%2%4%6%12 am: too few checklists (993) to judge1 am: too few checklists (844) to judge2 am: too few checklists (839) to judge3 am: too few checklists (1488) to judge4 am: too few checklists (5344) to judge5 am: 3.5% of 27016 checklists6 am: 3.8% of 83973 checklists7 am: 3.7% of 160717 checklists8 am: 3.9% of 160531 checklists9 am: 4.1% of 136968 checklists10 am: 4.4% of 119110 checklists11 am: 4.5% of 99116 checklists12 pm: 4.3% of 85078 checklists1 pm: 4.5% of 80688 checklists2 pm: 4.4% of 79140 checklists3 pm: 4.3% of 78599 checklists4 pm: 4.4% of 69767 checklists5 pm: 4.3% of 53229 checklists6 pm: 3.7% of 38769 checklists7 pm: too few checklists (24396) to judge8 pm: too few checklists (10155) to judge9 pm: too few checklists (4990) to judge10 pm: too few checklists (2463) to judge11 pm: too few checklists (1281) 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
January2.2%1.6%1.2%1.4%
February1.3%1.2%1.4%3.1%
March7.4%11%13%13%
April12%8.8%7.4%5.5%
May3.5%2.5%2.6%2.5%
June2.2%2.1%1.9%1.9%
July2.1%2.1%2.3%2.3%
August2.3%2.0%2.2%1.7%
September1.6%1.5%1.5%1.5%
October1.6%1.3%2.1%3.5%
November6.4%7.1%6.9%6.4%
December4.6%3.5%2.2%1.9%

Neighboring states

  • Illinois: arrives mid October, 16 weeks earlier than Wisconsin
  • Iowa: arrives late October, 15 weeks earlier than Wisconsin
  • Michigan: arrives mid July, 20 weeks later than Wisconsin
  • Minnesota: arrives late February, 1 week later than Wisconsin

Common questions

When do Hooded Mergansers arrive in Wisconsin?
Hooded Mergansers are winter birds in Wisconsin: the first arrive in mid February, they are common by late February, peak in late March (13% of checklists), and most are gone by early January.
When do Hooded Mergansers leave Wisconsin?
Most Hooded Mergansers have left Wisconsin by early January, when reports fall below half their usual rate. Stragglers are still reported until the second week of January.
When is the best time to see a Hooded Merganser in Wisconsin?
The Hooded Merganser is reported most often in late March, on about 13% of Wisconsin checklists.
Where in Wisconsin are Hooded Mergansers seen most often?
By county, Lincoln County, Sawyer County, and Price County have the highest peak reporting rates for the Hooded Merganser (counties with at least 200 checklists).