WhenToBird

Hydroprogne caspia · Laridae

When Do Caspian Terns Arrive in Kansas?

Adult Caspian Tern
Photo: Daughter Dad, CC BY 4.0 via iNaturalist

Caspian Terns mostly pass through Kansas: they arrive in early August, peak in the second week of September (2.0% of checklists), and most are gone by late September.

When to look

First arrivalsAug 1-7early August
Common byAug 1-7early August
PeakSep 8-14the second week of September
Most gone bySep 22-30late September

Best: the second week of September. First arrivals early August; most are gone by late September. Peak: on about 2.0% of Kansas checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprrare
  5. Mayrare
  6. Junrare
  7. Juluncommon
  8. Augpeak season
  9. Seppeak season
  10. Octrare
  11. Novnot usually seen
  12. Decnot usually seen

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

0%1%2%3%Jan 1-7: 0% of 8683 checklistsJan 8-14: 0% of 5710 checklistsJan 15-21: 0% of 5453 checklistsJan 22-31: 0% of 7868 checklistsFeb 1-7: 0% of 5579 checklistsFeb 8-14: 0% of 6307 checklistsFeb 15-21: 0% of 7830 checklistsFeb 22-28: 0% of 6124 checklistsMar 1-7: 0% of 6442 checklistsMar 8-14: 0% of 6925 checklistsMar 15-21: 0% of 7257 checklistsMar 22-31: 0% of 11527 checklistsApr 1-7: 0% of 8908 checklistsApr 8-14: 0.1% of 11070 checklistsApr 15-21: 0.3% of 11050 checklistsApr 22-30: 0.3% of 16381 checklistsMay 1-7: 0.3% of 15899 checklistsMay 8-14: 0.3% of 15349 checklistsMay 15-21: 0.3% of 10474 checklistsMay 22-31: 0.3% of 11264 checklistsJun 1-7: 0.2% of 6783 checklistsJun 8-14: 0.2% of 5654 checklistsJun 15-21: 0.1% of 4716 checklistsJun 22-30: 0.1% of 6232 checklistsJul 1-7: 0.1% of 5073 checklistsJul 8-14: 0.2% of 4528 checklistsJul 15-21: 0.2% of 4210 checklistsJul 22-31: 0.5% of 5986 checklistsAug 1-7: 0.8% of 4661 checklistsAug 8-14: 0.8% of 4762 checklistsAug 15-21: 0.9% of 4823 checklistsAug 22-31: 1.5% of 7214 checklistsSep 1-7: 2.7% of 5989 checklistsSep 8-14: 1.7% of 5549 checklistsSep 15-21: 1.5% of 5255 checklistsSep 22-30: 0.6% of 7370 checklistsOct 1-7: 0.2% of 5829 checklistsOct 8-14: 0.1% of 6183 checklistsOct 15-21: 0.1% of 5504 checklistsOct 22-31: 0% of 7289 checklistsNov 1-7: 0% of 5535 checklistsNov 8-14: 0% of 5462 checklistsNov 15-21: 0% of 4929 checklistsNov 22-30: 0% of 6627 checklistsDec 1-7: 0% of 4670 checklistsDec 8-14: 0% of 4805 checklistsDec 15-21: 0% of 6341 checklistsDec 22-31: 0% of 8186 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 Kansas 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 Kansas

Best counties

Share of checklists at the peak
  1. Miami CountyBest the second week of September · 118 checklists that week, 5,634 in all23%
  2. Osage CountyBest the second week of September · 39 checklists that week, 3,723 in all11%
  3. Neosho CountyBest late August · 52 checklists that week, 2,366 in all8.9%
  4. Douglas CountyBest late August · 819 checklists that week, 40,815 in all8.5%
  5. Brown CountyBest late August · 24 checklists that week, 2,536 in all8.3%
  6. Bourbon CountyBest late August · 13 checklists that week, 765 in all6.5%

Best spots

Share of checklists at the peak
  1. Clinton LakeDouglas County, best early September · 69 checklists that week, 1,461 in all52%
  2. Hillsdale Recreation AreaMiami County, best the second week of September · 24 checklists that week, 505 in all45%
  3. Hillsdale State ParkMiami County, best late September · 22 checklists that week, 432 in all41%
  4. Clinton Recreation AreaDouglas County, best early September · 40 checklists that week, 1,569 in all40%
  5. Clinton Recreation Area (west 3)Douglas County, best late August · 23 checklists that week, 268 in all30%
  6. Heritage LakeJohnson County, best the second week of June · 29 checklists that week, 1,092 in all15%

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

Best time of day

In Kansas, the Caspian Tern is most often listed on checklists started between 6 and 8 am (0.4% of those checklists).

0%0.5%12 am: too few checklists (150) to judge1 am: too few checklists (119) to judge2 am: too few checklists (97) to judge3 am: too few checklists (94) to judge4 am: too few checklists (124) to judge5 am: too few checklists (1459) to judge6 am: 0.3% of 12550 checklists7 am: 0.4% of 34128 checklists8 am: 0.3% of 45960 checklists9 am: 0.3% of 37806 checklists10 am: 0.3% of 32102 checklists11 am: 0.3% of 25896 checklists12 pm: 0.2% of 24203 checklists1 pm: 0.2% of 20269 checklists2 pm: 0.2% of 20772 checklists3 pm: 0.2% of 20978 checklists4 pm: 0.3% of 22094 checklists5 pm: 0.2% of 17739 checklists6 pm: 0.3% of 13963 checklists7 pm: 0.3% of 10110 checklists8 pm: too few checklists (4188) to judge9 pm: too few checklists (968) to judge10 pm: too few checklists (325) to judge11 pm: too few checklists (171) 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%0.1%0.3%0.3%
May0.3%0.3%0.3%0.3%
June0.2%0.2%0.1%0.1%
July0.1%0.2%0.2%0.5%
August0.8%0.8%0.9%1.5%
September2.7%1.7%1.5%0.6%
October0.2%0.1%0.1%0%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • Missouri: arrives the second week of July, 3 weeks earlier than Kansas
  • Iowa: arrives late July, 1 week earlier than Kansas
  • South Dakota: arrives mid April, 14 weeks earlier than Kansas
  • Illinois: arrives late March, 17 weeks earlier than Kansas

Common questions

When do Caspian Terns arrive in Kansas?
Caspian Terns mostly pass through Kansas: they arrive in early August, peak in the second week of September (2.0% of checklists), and most are gone by late September.
When do Caspian Terns leave Kansas?
Most Caspian Terns have left Kansas by late September, when reports fall below half their usual rate.
When is the best time to see a Caspian Tern in Kansas?
The Caspian Tern is reported most often in the second week of September, on about 2.0% of Kansas checklists.
Where in Kansas are Caspian Terns seen most often?
By county, Miami County, Osage County, and Neosho County have the highest peak reporting rates for the Caspian Tern (counties with at least 200 checklists).