WhenToBird

Lophodytes cucullatus · Anatidae

When Do Hooded Mergansers Arrive in Missouri?

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

Hooded Mergansers are winter birds in Missouri: the first arrive in late October, they are common by early November, peak in early December (6.9% of checklists), and most are gone by late March.

When to look

First arrivalsOct 22-31late October
Common byNov 1-7early November
PeakDec 1-7early December
Most gone byMar 22-31late March

Best: early December. First arrivals late October; most are gone by late March. Peak: on about 6.9% of Missouri checklists.

  1. Janpeak season
  2. Febcommon
  3. Marcommon
  4. Apruncommon
  5. Mayrare
  6. Junrare
  7. Julrare
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octuncommon
  11. Novpeak season
  12. Decpeak season

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

0%2%4%6%8%Jan 1-7: 6.0% of 12628 checklistsJan 8-14: 6.2% of 9076 checklistsJan 15-21: 5.1% of 8790 checklistsJan 22-31: 5.3% of 11986 checklistsFeb 1-7: 4.9% of 8987 checklistsFeb 8-14: 4.0% of 10394 checklistsFeb 15-21: 2.9% of 15472 checklistsFeb 22-28: 4.8% of 9917 checklistsMar 1-7: 4.0% of 9877 checklistsMar 8-14: 4.0% of 9570 checklistsMar 15-21: 3.1% of 10274 checklistsMar 22-31: 2.5% of 16156 checklistsApr 1-7: 2.0% of 12774 checklistsApr 8-14: 1.5% of 14048 checklistsApr 15-21: 1.4% of 14894 checklistsApr 22-30: 1.1% of 23288 checklistsMay 1-7: 0.7% of 22645 checklistsMay 8-14: 0.7% of 21384 checklistsMay 15-21: 0.9% of 13989 checklistsMay 22-31: 0.7% of 15784 checklistsJun 1-7: 0.7% of 9691 checklistsJun 8-14: 0.6% of 9036 checklistsJun 15-21: 0.4% of 7907 checklistsJun 22-30: 0.5% of 9831 checklistsJul 1-7: 0.3% of 8008 checklistsJul 8-14: 0.3% of 7202 checklistsJul 15-21: 0.2% of 7151 checklistsJul 22-31: 0.3% of 9833 checklistsAug 1-7: 0.1% of 7639 checklistsAug 8-14: 0.1% of 7507 checklistsAug 15-21: 0.1% of 7429 checklistsAug 22-31: 0.1% of 11182 checklistsSep 1-7: 0.1% of 9471 checklistsSep 8-14: 0.1% of 8501 checklistsSep 15-21: 0.1% of 8169 checklistsSep 22-30: 0.1% of 11572 checklistsOct 1-7: 0.1% of 9028 checklistsOct 8-14: 0.1% of 9413 checklistsOct 15-21: 0.2% of 8656 checklistsOct 22-31: 1.2% of 11625 checklistsNov 1-7: 3.2% of 8627 checklistsNov 8-14: 5.2% of 8284 checklistsNov 15-21: 6.0% of 8075 checklistsNov 22-30: 6.7% of 10430 checklistsDec 1-7: 6.8% of 7870 checklistsDec 8-14: 7.3% of 7567 checklistsDec 15-21: 5.8% of 9696 checklistsDec 22-31: 5.6% of 13142 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 Missouri 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.

Embed this map on your site

Where in Missouri

Best counties

Share of checklists at the peak
  1. Macon CountyBest mid December · 38 checklists that week, 1,377 in all65%
  2. Holt CountyBest late March · 49 checklists that week, 1,665 in all45%
  3. Ralls CountyBest the second week of January · 15 checklists that week, 1,204 in all43%
  4. Pike CountyBest mid March · 39 checklists that week, 1,685 in all43%
  5. Mississippi CountyBest early December · 14 checklists that week, 1,302 in all34%
  6. Monroe CountyBest early January · 15 checklists that week, 1,048 in all34%

Best spots

Share of checklists at the peak
  1. Longview Lake (Mouse Creek)Jackson County, best mid January · 29 checklists that week, 590 in all83%
  2. Smithville LakeClay County, best late January · 21 checklists that week, 598 in all72%
  3. Blue Springs Lake (Mirror Lakes)Jackson County, best late January · 22 checklists that week, 677 in all71%
  4. Lake RemoteClay County, best the second week of January · 34 checklists that week, 898 in all69%
  5. Clarence Cannon National Wildlife RefugePike County, best late March · 20 checklists that week, 708 in all68%
  6. Longview LakeJackson County, best mid January · 21 checklists that week, 2,343 in all67%

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

Best time of day

In Missouri, the Hooded Merganser is most often listed on checklists started between 1 and 3 pm (3.1% of those checklists).

0%1%2%3%4%12 am: too few checklists (205) to judge1 am: too few checklists (179) to judge2 am: too few checklists (204) to judge3 am: too few checklists (216) to judge4 am: too few checklists (630) to judge5 am: too few checklists (5072) to judge6 am: 1.6% of 27231 checklists7 am: 1.9% of 64162 checklists8 am: 1.9% of 67854 checklists9 am: 2.4% of 56515 checklists10 am: 2.5% of 47496 checklists11 am: 2.7% of 38845 checklists12 pm: 2.8% of 33383 checklists1 pm: 3.2% of 32503 checklists2 pm: 3.1% of 32615 checklists3 pm: 3.2% of 32514 checklists4 pm: 2.9% of 30274 checklists5 pm: 1.3% of 23446 checklists6 pm: 0.7% of 16374 checklists7 pm: too few checklists (10236) to judge8 pm: too few checklists (3133) to judge9 pm: too few checklists (722) to judge10 pm: too few checklists (405) to judge11 pm: too few checklists (261) 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
January6.0%6.2%5.1%5.3%
February4.9%4.0%2.9%4.8%
March4.0%4.0%3.1%2.5%
April2.0%1.5%1.4%1.1%
May0.7%0.7%0.9%0.7%
June0.7%0.6%0.4%0.5%
July0.3%0.3%0.2%0.3%
August0.1%0.1%0.1%0.1%
September0.1%0.1%0.1%0.1%
October0.1%0.1%0.2%1.2%
November3.2%5.2%6.0%6.7%
December6.8%7.3%5.8%5.6%

Neighboring states

  • Arkansas: arrives early November, 1 week later than Missouri
  • Iowa: arrives late October, in the same week than Missouri
  • Kansas: arrives late October, in the same week than Missouri
  • Illinois: arrives mid October, 1 week earlier than Missouri

Common questions

When do Hooded Mergansers arrive in Missouri?
Hooded Mergansers are winter birds in Missouri: the first arrive in late October, they are common by early November, peak in early December (6.9% of checklists), and most are gone by late March.
When do Hooded Mergansers leave Missouri?
Most Hooded Mergansers have left Missouri by late March, when reports fall below half their usual rate. Stragglers are still reported until late April.
When is the best time to see a Hooded Merganser in Missouri?
The Hooded Merganser is reported most often in early December, on about 6.9% of Missouri checklists.
Where in Missouri are Hooded Mergansers seen most often?
By county, Macon County, Holt County, and Ralls County have the highest peak reporting rates for the Hooded Merganser (counties with at least 200 checklists).