WhenToBird

Catharus ustulatus · Turdidae

When Do Swainson's Thrushes Arrive in South Dakota?

Adult Swainson's Thrush
Photo: Dani Alba, CC BY 4.0 via iNaturalist

Swainson's Thrushes arrive in South Dakota in late April, peak in the second week of May (16% of checklists), and most are gone by mid July.

When to look

First arrivalsApr 22-30late April
Common byApr 22-30late April
PeakMay 8-14the second week of May
Most gone byJul 15-21mid July

Best: the second week of May. First arrivals late April; most are gone by mid July. Peak: on about 16% of South Dakota checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Apruncommon
  5. Maypeak season
  6. Juncommon
  7. Juluncommon
  8. Augrare
  9. Sepuncommon
  10. Octrare
  11. Novnot usually seen
  12. Decnot usually seen

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

0%10%20%30%Jan 1-7: 0% of 1699 checklistsJan 8-14: 0% of 967 checklistsJan 15-21: 0% of 893 checklistsJan 22-31: 0% of 1338 checklistsFeb 1-7: 0% of 898 checklistsFeb 8-14: 0% of 1013 checklistsFeb 15-21: 0% of 1650 checklistsFeb 22-28: 0% of 1011 checklistsMar 1-7: 0% of 1304 checklistsMar 8-14: 0% of 1447 checklistsMar 15-21: 0% of 1524 checklistsMar 22-31: 0% of 2850 checklistsApr 1-7: 0% of 2170 checklistsApr 8-14: 0% of 2259 checklistsApr 15-21: 0.1% of 2578 checklistsApr 22-30: 0.6% of 3858 checklistsMay 1-7: 8.7% of 3532 checklistsMay 8-14: 18% of 4498 checklistsMay 15-21: 20% of 4211 checklistsMay 22-31: 9.6% of 5094 checklistsJun 1-7: 4.8% of 3279 checklistsJun 8-14: 4.9% of 3503 checklistsJun 15-21: 4.4% of 2861 checklistsJun 22-30: 6.0% of 3893 checklistsJul 1-7: 5.3% of 2666 checklistsJul 8-14: 4.7% of 2554 checklistsJul 15-21: 3.9% of 2412 checklistsJul 22-31: 1.3% of 2746 checklistsAug 1-7: 0.6% of 1842 checklistsAug 8-14: 0.5% of 1899 checklistsAug 15-21: 0.9% of 1757 checklistsAug 22-31: 1.9% of 2464 checklistsSep 1-7: 4.4% of 1894 checklistsSep 8-14: 5.1% of 1794 checklistsSep 15-21: 3.0% of 1671 checklistsSep 22-30: 1.2% of 2085 checklistsOct 1-7: 0.5% of 1429 checklistsOct 8-14: 0.2% of 1441 checklistsOct 15-21: 0.2% of 1330 checklistsOct 22-31: 0% of 1471 checklistsNov 1-7: 0% of 1168 checklistsNov 8-14: 0% of 1068 checklistsNov 15-21: 0% of 985 checklistsNov 22-30: 0% of 1108 checklistsDec 1-7: 0% of 890 checklistsDec 8-14: 0% of 957 checklistsDec 15-21: 0% of 1246 checklistsDec 22-31: 0% 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. Hughes CountyBest mid May · 116 checklists that week, 3,765 in all41%
  2. Union CountyBest the second week of May · 69 checklists that week, 882 in all38%
  3. Hyde CountyBest mid May · 18 checklists that week, 241 in all34%
  4. Lawrence CountyBest early July · 188 checklists that week, 3,847 in all34%
  5. Spink CountyBest the second week of May · 13 checklists that week, 317 in all33%
  6. Lincoln CountyBest mid May · 210 checklists that week, 2,721 in all32%

Best spots

Share of checklists at the peak
  1. Union GroveUnion County, best the second week of May · 25 checklists that week, 168 in all76%
  2. Bramble ParkCodington County, best the second week of May · 28 checklists that week, 280 in all74%
  3. PerryMinnehaha County, best the second week of May · 29 checklists that week, 215 in all65%
  4. ElmwoodMinnehaha County, best mid May · 37 checklists that week, 291 in all64%
  5. State Recreation AreaLawrence County, best the second week of July · 40 checklists that week, 500 in all61%
  6. Black Elk WildernessCuster County, best early June · 25 checklists that week, 160 in all56%

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

Best time of day

In South Dakota, the Swainson's Thrush is most often listed on checklists started between 6 and 8 am (6.7% of those checklists).

0%2%4%6%8%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: 7.6% of 3387 checklists7 am: 6.2% of 7718 checklists8 am: 5.1% of 10342 checklists9 am: 3.8% of 10758 checklists10 am: 3.8% of 9123 checklists11 am: 3.4% of 7814 checklists12 pm: 3.0% of 6876 checklists1 pm: 2.4% of 6801 checklists2 pm: 2.7% of 6673 checklists3 pm: 2.8% of 6344 checklists4 pm: 3.3% of 6412 checklists5 pm: 3.7% of 5570 checklists6 pm: 3.8% of 4276 checklists7 pm: 4.0% 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
January0%0%0%0%
February0%0%0%0%
March0%0%0%0%
April0%0%0.1%0.6%
May8.7%18%20%9.6%
June4.8%4.9%4.4%6.0%
July5.3%4.7%3.9%1.3%
August0.6%0.5%0.9%1.9%
September4.4%5.1%3.0%1.2%
October0.5%0.2%0.2%0%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • Nebraska: arrives late April, in the same week than South Dakota
  • North Dakota: arrives late April, in the same week than South Dakota
  • Minnesota: arrives late April, in the same week than South Dakota
  • Iowa: arrives late April, in the same week than South Dakota

Common questions

When do Swainson's Thrushes arrive in South Dakota?
Swainson's Thrushes arrive in South Dakota in late April, peak in the second week of May (16% of checklists), and most are gone by mid July.
When do Swainson's Thrushes leave South Dakota?
Most Swainson's Thrushes have left South Dakota by mid July, when reports fall below half their usual rate. Stragglers are still reported until late July.
When is the best time to see a Swainson's Thrush in South Dakota?
The Swainson's Thrush is reported most often in the second week of May, on about 16% of South Dakota checklists.
Where in South Dakota are Swainson's Thrushes seen most often?
By county, Hughes County, Union County, and Hyde County have the highest peak reporting rates for the Swainson's Thrush (counties with at least 200 checklists).