WhenToBird

Mergus serrator · Anatidae

When Do Red-breasted Mergansers Arrive in Indiana?

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

Red-breasted Mergansers are winter birds in Indiana: the first arrive in early November, they are common by the second week of November, peak in mid March (6.5% of checklists), and most are gone by mid April.

When to look

First arrivalsNov 1-7early November
Common byNov 8-14the second week of November
PeakMar 15-21mid March
Most gone byApr 15-21mid April

Best: mid March. First arrivals early November; most are gone by mid April. Peak: on about 6.5% of Indiana checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Mayrare
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octrare
  11. Novcommon
  12. Deccommon

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

0%2%4%6%8%Jan 1-7: 2.5% of 18123 checklistsJan 8-14: 2.4% of 12006 checklistsJan 15-21: 2.7% of 12403 checklistsJan 22-31: 2.6% of 16181 checklistsFeb 1-7: 2.5% of 12546 checklistsFeb 8-14: 2.2% of 14250 checklistsFeb 15-21: 2.0% of 18077 checklistsFeb 22-28: 3.7% of 13590 checklistsMar 1-7: 4.8% of 14545 checklistsMar 8-14: 6.1% of 14594 checklistsMar 15-21: 6.7% of 13894 checklistsMar 22-31: 6.6% of 22400 checklistsApr 1-7: 5.1% of 18069 checklistsApr 8-14: 3.3% of 19579 checklistsApr 15-21: 2.5% of 19518 checklistsApr 22-30: 1.3% of 30544 checklistsMay 1-7: 0.7% of 28430 checklistsMay 8-14: 0.5% of 30624 checklistsMay 15-21: 0.3% of 22920 checklistsMay 22-31: 0.1% of 21234 checklistsJun 1-7: 0.1% of 12279 checklistsJun 8-14: 0.1% of 10904 checklistsJun 15-21: 0.1% of 9488 checklistsJun 22-30: 0.1% of 11362 checklistsJul 1-7: 0.1% of 9947 checklistsJul 8-14: 0.1% of 9585 checklistsJul 15-21: 0.1% of 8929 checklistsJul 22-31: 0.1% of 12639 checklistsAug 1-7: 0.1% of 9528 checklistsAug 8-14: 0.1% of 9451 checklistsAug 15-21: 0% of 9442 checklistsAug 22-31: 0.1% of 14969 checklistsSep 1-7: 0.1% of 12628 checklistsSep 8-14: 0.1% of 11793 checklistsSep 15-21: 0.1% of 11396 checklistsSep 22-30: 0.1% of 14203 checklistsOct 1-7: 0.1% of 11365 checklistsOct 8-14: 0.2% of 12092 checklistsOct 15-21: 0.4% of 10440 checklistsOct 22-31: 0.7% of 13883 checklistsNov 1-7: 1.3% of 10476 checklistsNov 8-14: 2.2% of 9776 checklistsNov 15-21: 3.5% of 9035 checklistsNov 22-30: 4.5% of 12547 checklistsDec 1-7: 4.2% of 9078 checklistsDec 8-14: 2.9% of 8732 checklistsDec 15-21: 2.3% of 11024 checklistsDec 22-31: 2.3% of 15432 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 Indiana 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 Indiana

Best counties

Share of checklists at the peak
  1. Lake CountyBest late November · 425 checklists that week, 22,199 in all34%
  2. LaPorte CountyBest early December · 198 checklists that week, 12,564 in all25%
  3. Porter CountyBest mid January · 427 checklists that week, 29,087 in all23%
  4. Marion CountyBest mid March · 1591 checklists that week, 76,496 in all21%
  5. Union CountyBest early March · 84 checklists that week, 4,811 in all16%
  6. Franklin CountyBest early March · 58 checklists that week, 3,657 in all16%

Best spots

Share of checklists at the peak
  1. Whiting ParkLake County, best early December · 20 checklists that week, 297 in all94%
  2. Lakefront ParkLake County, best late March · 24 checklists that week, 1,190 in all92%
  3. Washington Park / Michigan CityLaPorte County, best the second week of January · 21 checklists that week, 2,145 in all85%

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

Best time of day

In Indiana, the Red-breasted Merganser is most often listed on checklists started between 12 and 2 pm (2.2% of those checklists).

0%1%2%3%12 am: too few checklists (240) to judge1 am: too few checklists (231) to judge2 am: too few checklists (222) to judge3 am: too few checklists (202) to judge4 am: too few checklists (674) to judge5 am: too few checklists (4329) to judge6 am: 2.3% of 20589 checklists7 am: 1.7% of 58470 checklists8 am: 1.6% of 86931 checklists9 am: 1.9% of 78239 checklists10 am: 1.9% of 66080 checklists11 am: 2.2% of 54904 checklists12 pm: 2.2% of 47610 checklists1 pm: 2.3% of 44814 checklists2 pm: 2.1% of 43790 checklists3 pm: 2.0% of 42983 checklists4 pm: 1.9% of 45349 checklists5 pm: 1.4% of 35993 checklists6 pm: 1.1% of 26447 checklists7 pm: 0.8% of 17740 checklists8 pm: too few checklists (7603) to judge9 pm: too few checklists (1721) to judge10 pm: too few checklists (517) to judge11 pm: too few checklists (272) 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
January2.5%2.4%2.7%2.6%
February2.5%2.2%2.0%3.7%
March4.8%6.1%6.7%6.6%
April5.1%3.3%2.5%1.3%
May0.7%0.5%0.3%0.1%
June0.1%0.1%0.1%0.1%
July0.1%0.1%0.1%0.1%
August0.1%0.1%0%0.1%
September0.1%0.1%0.1%0.1%
October0.1%0.2%0.4%0.7%
November1.3%2.2%3.5%4.5%
December4.2%2.9%2.3%2.3%

Neighboring states

  • Illinois: arrives late October, 1 week earlier than Indiana
  • Kentucky: arrives the second week of November, 1 week later than Indiana
  • Ohio: arrives late October, 1 week earlier than Indiana
  • Michigan: arrives late September, 5 weeks earlier than Indiana

Common questions

When do Red-breasted Mergansers arrive in Indiana?
Red-breasted Mergansers are winter birds in Indiana: the first arrive in early November, they are common by the second week of November, peak in mid March (6.5% of checklists), and most are gone by mid April.
When do Red-breasted Mergansers leave Indiana?
Most Red-breasted Mergansers have left Indiana by mid April, when reports fall below half their usual rate. Stragglers are still reported until late April.
When is the best time to see a Red-breasted Merganser in Indiana?
The Red-breasted Merganser is reported most often in mid March, on about 6.5% of Indiana checklists.
Where in Indiana are Red-breasted Mergansers seen most often?
By county, Lake County, LaPorte County, and Porter County have the highest peak reporting rates for the Red-breasted Merganser (counties with at least 200 checklists).