Ruddy Ducks arrive in South Dakota in the second week of March, peak in mid April (9.7% of checklists), and most are gone by late November.
When to look
First arrivalsMar 8-14the second week of March
Common byMar 8-14the second week of March
PeakApr 15-21mid April
Most gone byNov 22-30late November
Best: mid April. First arrivals the second week of March; most are gone by late November. Peak: on about 9.7% of South Dakota checklists.
Jannot usually seen
Febnot usually seen
Marcommon
Aprpeak season
Maycommon
Jununcommon
Juluncommon
Auguncommon
Sepuncommon
Octcommon
Novcommon
Decrare
Darker months: more checklists report it. Outlined: peak month.
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
0%few checklistsno data
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.
Deuel CountyBest mid April · 17 checklists that week, 444 in all49%
Kingsbury CountyBest early November · 38 checklists that week, 300 in all44%
Aurora CountyBest late October · 11 checklists that week, 348 in all36%
Edmunds CountyBest late May · 16 checklists that week, 466 in all35%
McPherson CountyBest early August · 11 checklists that week, 729 in all33%
Spink CountyBest late October · 10 checklists that week, 317 in all31%
Best spots
Share of checklists at the peak
Wall LakeMinnehaha County, best late April · 22 checklists that week, 450 in all24%
Farm IslandHughes County, best mid April · 25 checklists that week, 825 in all13%
SertomaMinnehaha County, best mid April · 36 checklists that week, 764 in all8.7%
Adams Nature AreaUnion County, best late May · 22 checklists that week, 327 in all4.1%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In South Dakota, the Ruddy Duck is most often listed on checklists started between 12 and 2 pm (4.4% of those checklists).
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
Month
Days 1-7
8-14
15-21
22-end
January
0.1%
0%
0%
0%
February
0%
0%
0.2%
0.2%
March
0.3%
2.1%
3.0%
4.4%
April
5.9%
8.7%
10%
9.9%
May
5.9%
4.5%
5.1%
4.0%
June
3.3%
2.6%
3.0%
3.0%
July
3.2%
2.8%
2.7%
2.5%
August
2.7%
2.8%
1.5%
2.0%
September
1.9%
1.8%
3.2%
2.2%
October
3.4%
3.7%
4.1%
6.7%
November
7.3%
5.8%
3.4%
1.3%
December
1.2%
1.1%
1.1%
0.1%
Neighboring states
Nebraska: arrives the second week of September, 24 weeks earlier than South Dakota
North Dakota: arrives early April, 3 weeks later than South Dakota
Minnesota: arrives mid March, 1 week later than South Dakota
Iowa: arrives late September, 22 weeks earlier than South Dakota
Common questions
When do Ruddy Ducks arrive in South Dakota?
Ruddy Ducks arrive in South Dakota in the second week of March, peak in mid April (9.7% of checklists), and most are gone by late November.
When do Ruddy Ducks leave South Dakota?
Most Ruddy Ducks have left South Dakota by late November, when reports fall below half their usual rate. Stragglers are still reported until the second week of December.
When is the best time to see a Ruddy Duck in South Dakota?
The Ruddy Duck is reported most often in mid April, on about 9.7% of South Dakota checklists.
Where in South Dakota are Ruddy Ducks seen most often?
By county, Deuel County, Kingsbury County, and Aurora County have the highest peak reporting rates for the Ruddy Duck (counties with at least 200 checklists).