WhenToBird

Anas platyrhynchos · Anatidae

When Do Mallards Arrive in South Dakota?

Adult male Mallard
Photo: euqirneto, CC BY 4.0 via iNaturalist

Mallards are in South Dakota all year, but most are here in spring: numbers build from early March, peak in the second week of April (47% of checklists), and fall back by mid May. In the quietest week (the second week of February) they are still on about 15% of checklists.

When to look

Numbers buildMar 1-7early March
PeakApr 8-14the second week of April
Fall back byMay 15-21mid May
FewestFeb 8-14the second week of February

Best: the second week of April. Here all year; numbers build from early March and fall back by mid May. Peak: on about 47% of South Dakota checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Juncommon
  7. Juluncommon
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Deccommon

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

0%20%40%60%Jan 1-7: 18% of 1699 checklistsJan 8-14: 21% of 967 checklistsJan 15-21: 21% of 893 checklistsJan 22-31: 19% of 1338 checklistsFeb 1-7: 18% of 898 checklistsFeb 8-14: 14% of 1013 checklistsFeb 15-21: 14% of 1650 checklistsFeb 22-28: 24% of 1011 checklistsMar 1-7: 31% of 1304 checklistsMar 8-14: 36% of 1447 checklistsMar 15-21: 38% of 1524 checklistsMar 22-31: 43% of 2850 checklistsApr 1-7: 44% of 2170 checklistsApr 8-14: 48% of 2259 checklistsApr 15-21: 47% of 2578 checklistsApr 22-30: 44% of 3858 checklistsMay 1-7: 38% of 3532 checklistsMay 8-14: 35% of 4498 checklistsMay 15-21: 33% of 4211 checklistsMay 22-31: 31% of 5094 checklistsJun 1-7: 24% of 3279 checklistsJun 8-14: 21% of 3503 checklistsJun 15-21: 19% of 2861 checklistsJun 22-30: 19% of 3893 checklistsJul 1-7: 17% of 2666 checklistsJul 8-14: 14% of 2554 checklistsJul 15-21: 16% of 2412 checklistsJul 22-31: 17% of 2746 checklistsAug 1-7: 20% of 1842 checklistsAug 8-14: 18% of 1899 checklistsAug 15-21: 19% of 1757 checklistsAug 22-31: 17% of 2464 checklistsSep 1-7: 17% of 1894 checklistsSep 8-14: 20% of 1794 checklistsSep 15-21: 20% of 1671 checklistsSep 22-30: 18% of 2085 checklistsOct 1-7: 20% of 1429 checklistsOct 8-14: 21% of 1441 checklistsOct 15-21: 23% of 1330 checklistsOct 22-31: 24% of 1471 checklistsNov 1-7: 28% of 1168 checklistsNov 8-14: 30% of 1068 checklistsNov 15-21: 29% of 985 checklistsNov 22-30: 24% of 1108 checklistsDec 1-7: 24% of 890 checklistsDec 8-14: 25% of 957 checklistsDec 15-21: 21% of 1246 checklistsDec 22-31: 18% of 1514 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 Dakota 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 Dakota

Best counties

Share of checklists at the peak
  1. Hyde CountyBest mid May · 18 checklists that week, 241 in all83%
  2. Edmunds CountyBest mid April · 12 checklists that week, 466 in all75%
  3. Deuel CountyBest the second week of April · 16 checklists that week, 444 in all73%
  4. Bennett CountyBest mid March · 15 checklists that week, 575 in all71%
  5. Codington CountyBest mid April · 55 checklists that week, 1,303 in all70%
  6. Aurora CountyBest late April · 17 checklists that week, 348 in all69%

Best spots

Share of checklists at the peak
  1. Canyon Lake ParkPennington County, best late December · 65 checklists that week, 2,659 in all99%
  2. SertomaMinnehaha County, best early May · 52 checklists that week, 764 in all96%
  3. Moccasin Creek ComplexBrown County, best the second week of May · 38 checklists that week, 209 in all95%
  4. Bramble ParkCodington County, best late April · 23 checklists that week, 280 in all91%

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

Best time of day

In South Dakota, the Mallard is most often listed on checklists started between 5 and 7 pm (32% of those checklists).

0%10%20%30%40%12 am: too few checklists (49) to judge1 am: too few checklists (44) to judge2 am: too few checklists (33) to judge3 am: too few checklists (59) to judge4 am: too few checklists (227) to judge5 am: too few checklists (1080) to judge6 am: 27% of 3387 checklists7 am: 33% of 7718 checklists8 am: 25% of 10342 checklists9 am: 25% of 10758 checklists10 am: 22% of 9123 checklists11 am: 24% of 7814 checklists12 pm: 25% of 6876 checklists1 pm: 29% of 6801 checklists2 pm: 27% of 6673 checklists3 pm: 26% of 6344 checklists4 pm: 26% of 6412 checklists5 pm: 32% of 5570 checklists6 pm: 31% of 4276 checklists7 pm: 29% of 3183 checklists8 pm: too few checklists (1499) to judge9 pm: too few checklists (329) to judge10 pm: too few checklists (82) to judge11 pm: too few checklists (42) 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
January18%21%21%19%
February18%14%14%24%
March31%36%38%43%
April44%48%47%44%
May38%35%33%31%
June24%21%19%19%
July17%14%16%17%
August20%18%19%17%
September17%20%20%18%
October20%21%23%24%
November28%30%29%24%
December24%25%21%18%

Neighboring states

  • Nebraska: arrives late February, 1 week earlier than South Dakota
  • North Dakota: arrives mid March, 2 weeks later than South Dakota
  • Minnesota: arrives the second week of March, 1 week later than South Dakota
  • Iowa: arrives late February, 1 week earlier than South Dakota

Common questions

When do Mallards arrive in South Dakota?
Mallards are in South Dakota all year, but most are here in spring: numbers build from early March, peak in the second week of April (47% of checklists), and fall back by mid May. In the quietest week (the second week of February) they are still on about 15% of checklists.
When do Mallards leave South Dakota?
Mallards never fully leave South Dakota: numbers fall back below half their usual rate by mid May, but some are still reported in every week, about 15% of checklists at the low.
When is the best time to see a Mallard in South Dakota?
The Mallard is reported most often in the second week of April, on about 47% of South Dakota checklists.
Where in South Dakota are Mallards seen most often?
By county, Hyde County, Edmunds County, and Deuel County have the highest peak reporting rates for the Mallard (counties with at least 200 checklists).