WhenToBird

Mergus serrator · Anatidae

When Do Red-breasted Mergansers Arrive in South Carolina?

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

Red-breasted Mergansers are winter birds in South Carolina: they arrive in mid November, peak in the second week of March (3.1% of checklists), and most are gone by mid April.

When to look

First arrivalsNov 15-21mid November
Common byNov 15-21mid November
PeakMar 8-14the second week of March
Most gone byApr 15-21mid April

Best: the second week of March. First arrivals mid November; most are gone by mid April. Peak: on about 3.1% of South Carolina checklists.

  1. Janpeak season
  2. Febcommon
  3. Marpeak season
  4. Aprcommon
  5. Mayuncommon
  6. Junrare
  7. Julrare
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octnot usually seen
  11. Novcommon
  12. Decpeak season

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

0%1%2%3%4%Jan 1-7: 2.9% of 15487 checklistsJan 8-14: 2.8% of 11691 checklistsJan 15-21: 3.4% of 11994 checklistsJan 22-31: 2.3% of 16225 checklistsFeb 1-7: 2.5% of 12192 checklistsFeb 8-14: 1.8% of 14044 checklistsFeb 15-21: 1.7% of 18483 checklistsFeb 22-28: 2.7% of 12045 checklistsMar 1-7: 2.9% of 11511 checklistsMar 8-14: 3.5% of 11704 checklistsMar 15-21: 2.8% of 11526 checklistsMar 22-31: 2.8% of 17386 checklistsApr 1-7: 1.6% of 13148 checklistsApr 8-14: 1.5% of 13193 checklistsApr 15-21: 1.1% of 13936 checklistsApr 22-30: 0.9% of 19002 checklistsMay 1-7: 0.8% of 14133 checklistsMay 8-14: 0.7% of 13668 checklistsMay 15-21: 0.5% of 11064 checklistsMay 22-31: 0.5% of 14461 checklistsJun 1-7: 0.5% of 10231 checklistsJun 8-14: 0.3% of 9417 checklistsJun 15-21: 0.2% of 8012 checklistsJun 22-30: 0.2% of 9720 checklistsJul 1-7: 0.2% of 7907 checklistsJul 8-14: 0.1% of 7338 checklistsJul 15-21: 0.1% of 7312 checklistsJul 22-31: 0.1% of 10877 checklistsAug 1-7: 0.1% of 7816 checklistsAug 8-14: 0.1% of 7655 checklistsAug 15-21: 0.1% of 7797 checklistsAug 22-31: 0.1% of 11246 checklistsSep 1-7: 0.1% of 8956 checklistsSep 8-14: 0.1% of 8929 checklistsSep 15-21: 0.1% of 9389 checklistsSep 22-30: 0.1% of 13028 checklistsOct 1-7: 0.1% of 11063 checklistsOct 8-14: 0.1% of 10968 checklistsOct 15-21: 0.1% of 10264 checklistsOct 22-31: 0.1% of 12917 checklistsNov 1-7: 0.1% of 8802 checklistsNov 8-14: 0.4% of 8339 checklistsNov 15-21: 0.8% of 8798 checklistsNov 22-30: 1.9% of 12925 checklistsDec 1-7: 2.1% of 8541 checklistsDec 8-14: 2.5% of 8609 checklistsDec 15-21: 2.1% of 9961 checklistsDec 22-31: 3.0% of 17541 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 South Carolina 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 South Carolina

Best counties

Share of checklists at the peak
  1. Georgetown CountyBest mid January · 866 checklists that week, 32,234 in all14%
  2. Jasper CountyBest late April · 376 checklists that week, 12,443 in all9.1%
  3. Horry CountyBest the second week of March · 718 checklists that week, 27,518 in all7.0%
  4. McCormick CountyBest mid March · 33 checklists that week, 1,566 in all6.7%
  5. Marlboro CountyBest early May · 15 checklists that week, 686 in all6.5%
  6. Charleston CountyBest mid March · 2088 checklists that week, 102,218 in all6.2%

Best spots

Share of checklists at the peak
  1. Folly BeachCharleston County, best the second week of January · 28 checklists that week, 476 in all64%
  2. Russell Burgess Coastal PreserveHorry County, best late March · 39 checklists that week, 1,043 in all62%
  3. High Battery ParkCharleston County, best the second week of January · 24 checklists that week, 272 in all56%
  4. Lighthouse Inlet Heritage PreserveCharleston County, best the second week of March · 39 checklists that week, 1,859 in all51%

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

Best time of day

In South Carolina, the Red-breasted Merganser is most often listed on checklists started between 9 and 11 am (1.7% of those checklists).

0%0.5%1%1.5%2%12 am: too few checklists (222) to judge1 am: too few checklists (160) to judge2 am: too few checklists (132) to judge3 am: too few checklists (212) to judge4 am: too few checklists (267) to judge5 am: too few checklists (1898) to judge6 am: 1.0% of 19280 checklists7 am: 1.3% of 66492 checklists8 am: 1.3% of 73941 checklists9 am: 1.7% of 63039 checklists10 am: 1.6% of 52652 checklists11 am: 1.3% of 41908 checklists12 pm: 1.3% of 36782 checklists1 pm: 1.5% of 33300 checklists2 pm: 1.5% of 32248 checklists3 pm: 1.4% of 35451 checklists4 pm: 1.1% of 34410 checklists5 pm: 0.6% of 27073 checklists6 pm: 0.4% of 17375 checklists7 pm: too few checklists (10313) to judge8 pm: too few checklists (2756) to judge9 pm: too few checklists (672) to judge10 pm: too few checklists (412) to judge11 pm: too few checklists (256) 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
January2.9%2.8%3.4%2.3%
February2.5%1.8%1.7%2.7%
March2.9%3.5%2.8%2.8%
April1.6%1.5%1.1%0.9%
May0.8%0.7%0.5%0.5%
June0.5%0.3%0.2%0.2%
July0.2%0.1%0.1%0.1%
August0.1%0.1%0.1%0.1%
September0.1%0.1%0.1%0.1%
October0.1%0.1%0.1%0.1%
November0.1%0.4%0.8%1.9%
December2.1%2.5%2.1%3.0%

Neighboring states

  • North Carolina: arrives mid November, in the same week than South Carolina
  • Georgia: arrives the second week of November, 1 week earlier than South Carolina
  • Tennessee: arrives early November, 2 weeks earlier than South Carolina
  • Virginia: arrives mid November, in the same week than South Carolina

Common questions

When do Red-breasted Mergansers arrive in South Carolina?
Red-breasted Mergansers are winter birds in South Carolina: they arrive in mid November, peak in the second week of March (3.1% of checklists), and most are gone by mid April.
When do Red-breasted Mergansers leave South Carolina?
Most Red-breasted Mergansers have left South Carolina by mid April, when reports fall below half their usual rate.
When is the best time to see a Red-breasted Merganser in South Carolina?
The Red-breasted Merganser is reported most often in the second week of March, on about 3.1% of South Carolina checklists.
Where in South Carolina are Red-breasted Mergansers seen most often?
By county, Georgetown County, Jasper County, and Horry County have the highest peak reporting rates for the Red-breasted Merganser (counties with at least 200 checklists).