WhenToBird

Mergus serrator · Anatidae

When Do Red-breasted Mergansers Arrive in Kentucky?

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

Red-breasted Mergansers are winter birds in Kentucky: they arrive in the second week of November, peak in late November (2.0% of checklists), and most are gone by late April.

When to look

First arrivalsNov 8-14the second week of November
Common byNov 8-14the second week of November
PeakNov 22-30late November
Most gone byApr 22-30late April

Best: late November. First arrivals the second week of November; most are gone by late April. Peak: on about 2.0% of Kentucky checklists.

  1. Januncommon
  2. Febcommon
  3. Marpeak season
  4. Aprcommon
  5. Mayuncommon
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octrare
  11. Novpeak season
  12. Decpeak season

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

0%1%2%3%Jan 1-7: 0.7% of 6923 checklistsJan 8-14: 0.5% of 4900 checklistsJan 15-21: 0.5% of 5016 checklistsJan 22-31: 0.5% of 6611 checklistsFeb 1-7: 0.8% of 4986 checklistsFeb 8-14: 0.9% of 5677 checklistsFeb 15-21: 0.6% of 8880 checklistsFeb 22-28: 1.6% of 5567 checklistsMar 1-7: 1.1% of 5397 checklistsMar 8-14: 1.4% of 5462 checklistsMar 15-21: 2.0% of 5733 checklistsMar 22-31: 1.2% of 9043 checklistsApr 1-7: 1.2% of 6763 checklistsApr 8-14: 0.8% of 7498 checklistsApr 15-21: 0.6% of 8486 checklistsApr 22-30: 0.6% of 13396 checklistsMay 1-7: 0.3% of 10825 checklistsMay 8-14: 0.3% of 11495 checklistsMay 15-21: 0.1% of 7363 checklistsMay 22-31: 0.1% of 8800 checklistsJun 1-7: 0.1% of 5381 checklistsJun 8-14: 0.1% of 5244 checklistsJun 15-21: 0% of 4730 checklistsJun 22-30: 0% of 5470 checklistsJul 1-7: 0% of 4567 checklistsJul 8-14: 0.1% of 4287 checklistsJul 15-21: 0.1% of 4097 checklistsJul 22-31: 0% of 6044 checklistsAug 1-7: 0% of 4647 checklistsAug 8-14: 0% of 4256 checklistsAug 15-21: 0% of 4484 checklistsAug 22-31: 0% of 6434 checklistsSep 1-7: 0% of 5450 checklistsSep 8-14: 0% of 5157 checklistsSep 15-21: 0% of 5530 checklistsSep 22-30: 0% of 6710 checklistsOct 1-7: 0% of 5403 checklistsOct 8-14: 0.1% of 5943 checklistsOct 15-21: 0.1% of 4873 checklistsOct 22-31: 0.1% of 6584 checklistsNov 1-7: 0.2% of 5008 checklistsNov 8-14: 0.7% of 4677 checklistsNov 15-21: 1.5% of 4419 checklistsNov 22-30: 1.7% of 5933 checklistsDec 1-7: 2.7% of 4479 checklistsDec 8-14: 1.5% of 4687 checklistsDec 15-21: 0.6% of 6239 checklistsDec 22-31: 0.5% of 7976 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 Kentucky 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 Kentucky

Best counties

Share of checklists at the peak
  1. Russell CountyBest late November · 23 checklists that week, 1,208 in all15%
  2. Hardin CountyBest late March · 66 checklists that week, 2,194 in all14%
  3. Rowan CountyBest the second week of April · 41 checklists that week, 2,188 in all14%
  4. Rockcastle CountyBest the second week of March · 14 checklists that week, 598 in all14%
  5. Clark CountyBest late November · 14 checklists that week, 844 in all13%
  6. Taylor CountyBest mid February · 43 checklists that week, 740 in all11%

Best spots

Share of checklists at the peak
  1. Lake PeeweeHopkins County, best late November · 25 checklists that week, 256 in all31%
  2. Cumberland Recreation Area (southeast)Pulaski County, best late March · 23 checklists that week, 413 in all28%
  3. Minor Clark Fish HatcheryRowan County, best late April · 38 checklists that week, 882 in all27%
  4. Freeman Lake ParkHardin County, best late December · 25 checklists that week, 461 in all26%
  5. Lake HickmanFayette County, best the second week of March · 53 checklists that week, 1,926 in all22%

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

Best time of day

In Kentucky, the Red-breasted Merganser is most often listed on checklists started between 1 and 3 pm (0.8% of those checklists).

0%0.5%1%12 am: too few checklists (140) to judge1 am: too few checklists (120) to judge2 am: too few checklists (88) to judge3 am: too few checklists (95) to judge4 am: too few checklists (151) to judge5 am: too few checklists (1289) to judge6 am: 0.3% of 8227 checklists7 am: 0.4% of 24608 checklists8 am: 0.3% of 36577 checklists9 am: 0.4% of 34626 checklists10 am: 0.6% of 28796 checklists11 am: 0.8% of 22781 checklists12 pm: 0.8% of 19848 checklists1 pm: 0.8% of 19369 checklists2 pm: 0.9% of 19367 checklists3 pm: 0.7% of 19618 checklists4 pm: 0.6% of 19464 checklists5 pm: 0.4% of 16639 checklists6 pm: 0.3% of 12714 checklists7 pm: 0.2% of 8457 checklists8 pm: too few checklists (3447) to judge9 pm: too few checklists (684) to judge10 pm: too few checklists (267) to judge11 pm: too few checklists (158) 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
January0.7%0.5%0.5%0.5%
February0.8%0.9%0.6%1.6%
March1.1%1.4%2.0%1.2%
April1.2%0.8%0.6%0.6%
May0.3%0.3%0.1%0.1%
June0.1%0.1%0%0%
July0%0.1%0.1%0%
August0%0%0%0%
September0%0%0%0%
October0%0.1%0.1%0.1%
November0.2%0.7%1.5%1.7%
December2.7%1.5%0.6%0.5%

Neighboring states

  • Tennessee: arrives early November, 1 week earlier than Kentucky
  • Indiana: arrives early November, 1 week earlier than Kentucky
  • Ohio: arrives late October, 2 weeks earlier than Kentucky
  • Illinois: arrives late October, 2 weeks earlier than Kentucky

Common questions

When do Red-breasted Mergansers arrive in Kentucky?
Red-breasted Mergansers are winter birds in Kentucky: they arrive in the second week of November, peak in late November (2.0% of checklists), and most are gone by late April.
When do Red-breasted Mergansers leave Kentucky?
Most Red-breasted Mergansers have left Kentucky by late April, when reports fall below half their usual rate.
When is the best time to see a Red-breasted Merganser in Kentucky?
The Red-breasted Merganser is reported most often in late November, on about 2.0% of Kentucky checklists.
Where in Kentucky are Red-breasted Mergansers seen most often?
By county, Russell County, Hardin County, and Rowan County have the highest peak reporting rates for the Red-breasted Merganser (counties with at least 200 checklists).