WhenToBird

Mergus merganser · Anatidae

When Do Common Mergansers Arrive in Kansas?

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

Common Mergansers are winter birds in Kansas: the first arrive in the second week of November, they are common by early December, peak in early February (8.3% of checklists), and most are gone by the second week of March.

When to look

First arrivalsNov 8-14the second week of November
Common byDec 1-7early December
PeakFeb 1-7early February
Most gone byMar 8-14the second week of March

Best: early February. First arrivals the second week of November; most are gone by the second week of March. Peak: on about 8.3% of Kansas checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Aprrare
  5. Maynot usually seen
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octnot usually seen
  11. Novuncommon
  12. Deccommon

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

0%5%10%Jan 1-7: 6.3% of 8683 checklistsJan 8-14: 7.7% of 5710 checklistsJan 15-21: 7.4% of 5453 checklistsJan 22-31: 8.6% of 7868 checklistsFeb 1-7: 8.6% of 5579 checklistsFeb 8-14: 7.5% of 6307 checklistsFeb 15-21: 5.1% of 7830 checklistsFeb 22-28: 7.2% of 6124 checklistsMar 1-7: 4.5% of 6442 checklistsMar 8-14: 3.7% of 6925 checklistsMar 15-21: 2.1% of 7257 checklistsMar 22-31: 0.9% of 11527 checklistsApr 1-7: 0.7% of 8908 checklistsApr 8-14: 0.3% of 11070 checklistsApr 15-21: 0.3% of 11050 checklistsApr 22-30: 0.2% of 16381 checklistsMay 1-7: 0.1% of 15899 checklistsMay 8-14: 0.1% of 15349 checklistsMay 15-21: 0.1% of 10474 checklistsMay 22-31: 0.1% of 11264 checklistsJun 1-7: 0.1% of 6783 checklistsJun 8-14: 0.1% of 5654 checklistsJun 15-21: 0% of 4716 checklistsJun 22-30: 0.1% of 6232 checklistsJul 1-7: 0.1% of 5073 checklistsJul 8-14: 0.1% of 4528 checklistsJul 15-21: 0.1% of 4210 checklistsJul 22-31: 0% of 5986 checklistsAug 1-7: 0.1% of 4661 checklistsAug 8-14: 0.1% of 4762 checklistsAug 15-21: 0.1% of 4823 checklistsAug 22-31: 0.1% of 7214 checklistsSep 1-7: 0% of 5989 checklistsSep 8-14: 0.1% of 5549 checklistsSep 15-21: 0% of 5255 checklistsSep 22-30: 0.1% of 7370 checklistsOct 1-7: 0.1% of 5829 checklistsOct 8-14: 0.1% of 6183 checklistsOct 15-21: 0.1% of 5504 checklistsOct 22-31: 0.1% of 7289 checklistsNov 1-7: 0.5% of 5535 checklistsNov 8-14: 1.3% of 5462 checklistsNov 15-21: 1.8% of 4929 checklistsNov 22-30: 2.1% of 6627 checklistsDec 1-7: 3.1% of 4670 checklistsDec 8-14: 4.0% of 4805 checklistsDec 15-21: 4.2% of 6341 checklistsDec 22-31: 4.5% of 8186 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 Kansas 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 Kansas

Best counties

Share of checklists at the peak
  1. Comanche CountyBest early January · 19 checklists that week, 769 in all49%
  2. Morris CountyBest the second week of February · 23 checklists that week, 556 in all42%
  3. Jewell CountyBest late January · 12 checklists that week, 612 in all38%
  4. Wyandotte CountyBest early January · 99 checklists that week, 3,430 in all35%
  5. Jefferson CountyBest early February · 105 checklists that week, 6,538 in all34%
  6. Clark CountyBest late February · 14 checklists that week, 697 in all33%

Best spots

Share of checklists at the peak
  1. Perry Recreation AreaJefferson County, best late January · 25 checklists that week, 830 in all78%
  2. Tuttle Creek Recreation Area (south 2)Riley County, best early February · 25 checklists that week, 227 in all66%
  3. Lake ShawneeShawnee County, best late February · 45 checklists that week, 1,134 in all65%
  4. Wyandotte Co LakeWyandotte County, best early February · 27 checklists that week, 882 in all64%

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

Best time of day

In Kansas, the Common Merganser is most often listed on checklists started between 1 and 3 pm (2.4% of those checklists).

0%1%2%3%12 am: too few checklists (150) to judge1 am: too few checklists (119) to judge2 am: too few checklists (97) to judge3 am: too few checklists (94) to judge4 am: too few checklists (124) to judge5 am: too few checklists (1459) to judge6 am: 0.2% of 12550 checklists7 am: 1.2% of 34128 checklists8 am: 1.7% of 45960 checklists9 am: 2.1% of 37806 checklists10 am: 2.4% of 32102 checklists11 am: 2.4% of 25896 checklists12 pm: 2.2% of 24203 checklists1 pm: 2.6% of 20269 checklists2 pm: 2.2% of 20772 checklists3 pm: 2.1% of 20978 checklists4 pm: 2.3% of 22094 checklists5 pm: 1.3% of 17739 checklists6 pm: 0.3% of 13963 checklists7 pm: 0.2% of 10110 checklists8 pm: too few checklists (4188) to judge9 pm: too few checklists (968) to judge10 pm: too few checklists (325) to judge11 pm: too few checklists (171) 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
January6.3%7.7%7.4%8.6%
February8.6%7.5%5.1%7.2%
March4.5%3.7%2.1%0.9%
April0.7%0.3%0.3%0.2%
May0.1%0.1%0.1%0.1%
June0.1%0.1%0%0.1%
July0.1%0.1%0.1%0%
August0.1%0.1%0.1%0.1%
September0%0.1%0%0.1%
October0.1%0.1%0.1%0.1%
November0.5%1.3%1.8%2.1%
December3.1%4.0%4.2%4.5%

Neighboring states

  • Nebraska: arrives early November, 1 week earlier than Kansas
  • Oklahoma: arrives early December, 3 weeks later than Kansas
  • Missouri: arrives mid November, 1 week later than Kansas
  • Iowa: arrives early November, 1 week earlier than Kansas

Common questions

When do Common Mergansers arrive in Kansas?
Common Mergansers are winter birds in Kansas: the first arrive in the second week of November, they are common by early December, peak in early February (8.3% of checklists), and most are gone by the second week of March.
When do Common Mergansers leave Kansas?
Most Common Mergansers have left Kansas by the second week of March, when reports fall below half their usual rate. Stragglers are still reported until late March.
When is the best time to see a Common Merganser in Kansas?
The Common Merganser is reported most often in early February, on about 8.3% of Kansas checklists.
Where in Kansas are Common Mergansers seen most often?
By county, Comanche County, Morris County, and Jewell County have the highest peak reporting rates for the Common Merganser (counties with at least 200 checklists).