WhenToBird

Sterna forsteri · Laridae

When Do Forster's Terns Arrive in Mississippi?

Adult Forster's Tern
Photo: Aitor, CC BY 4.0 via iNaturalist

Forster's Terns are in Mississippi all year, but most are here in fall: numbers build from mid August, peak in the second week of September (9.2% of checklists), and fall back by mid November. In the quietest week (the second week of June) they are still on about 2.4% of checklists.

When to look

Numbers buildAug 15-21mid August
PeakSep 8-14the second week of September
Fall back byNov 15-21mid November
FewestJun 8-14the second week of June

Best: the second week of September. Here all year; numbers build from mid August and fall back by mid November. Peak: on about 9.2% of Mississippi checklists.

  1. Janpeak season
  2. Febcommon
  3. Marcommon
  4. Aprcommon
  5. Maycommon
  6. Jununcommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

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

0%5%10%Jan 1-7: 6.0% of 4836 checklistsJan 8-14: 7.1% of 3323 checklistsJan 15-21: 7.1% of 3400 checklistsJan 22-31: 7.4% of 4705 checklistsFeb 1-7: 6.1% of 3387 checklistsFeb 8-14: 5.6% of 3911 checklistsFeb 15-21: 5.0% of 4691 checklistsFeb 22-28: 6.3% of 3409 checklistsMar 1-7: 4.8% of 3276 checklistsMar 8-14: 6.5% of 3273 checklistsMar 15-21: 6.5% of 3552 checklistsMar 22-31: 6.6% of 5618 checklistsApr 1-7: 7.1% of 4432 checklistsApr 8-14: 6.2% of 4907 checklistsApr 15-21: 6.0% of 5239 checklistsApr 22-30: 6.6% of 7043 checklistsMay 1-7: 5.0% of 4597 checklistsMay 8-14: 4.1% of 4383 checklistsMay 15-21: 4.2% of 3088 checklistsMay 22-31: 3.2% of 3805 checklistsJun 1-7: 2.0% of 2658 checklistsJun 8-14: 2.3% of 2469 checklistsJun 15-21: 3.0% of 2112 checklistsJun 22-30: 2.5% of 2534 checklistsJul 1-7: 3.0% of 2099 checklistsJul 8-14: 3.0% of 1885 checklistsJul 15-21: 4.5% of 1811 checklistsJul 22-31: 3.9% of 2793 checklistsAug 1-7: 4.4% of 2045 checklistsAug 8-14: 5.4% of 2210 checklistsAug 15-21: 7.0% of 2437 checklistsAug 22-31: 9.0% of 3415 checklistsSep 1-7: 9.9% of 2837 checklistsSep 8-14: 8.5% of 2585 checklistsSep 15-21: 9.0% of 2870 checklistsSep 22-30: 7.8% of 3610 checklistsOct 1-7: 5.9% of 2938 checklistsOct 8-14: 8.3% of 3457 checklistsOct 15-21: 7.4% of 3168 checklistsOct 22-31: 8.5% of 3752 checklistsNov 1-7: 5.7% of 2847 checklistsNov 8-14: 6.3% of 2648 checklistsNov 15-21: 5.9% of 2599 checklistsNov 22-30: 6.0% of 3389 checklistsDec 1-7: 5.4% of 2419 checklistsDec 8-14: 6.3% of 2526 checklistsDec 15-21: 6.4% of 2966 checklistsDec 22-31: 6.6% of 4466 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 Mississippi 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 Mississippi

Best counties

Share of checklists at the peak
  1. Yalobusha CountyBest early December · 17 checklists that week, 368 in all54%
  2. Panola CountyBest the second week of March · 17 checklists that week, 1,311 in all36%
  3. Rankin CountyBest mid January · 74 checklists that week, 1,877 in all35%
  4. Madison CountyBest mid January · 159 checklists that week, 6,285 in all33%
  5. Harrison CountyBest late August · 378 checklists that week, 22,824 in all31%
  6. Hancock CountyBest early November · 84 checklists that week, 7,194 in all30%

Best spots

Share of checklists at the peak
  1. Pelahatchie CreekRankin County, best late December · 21 checklists that week, 161 in all76%

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

Best time of day

In Mississippi, the Forster's Tern is most often listed on checklists started between 7 and 9 am (8.4% of those checklists).

0%5%10%12 am: too few checklists (54) to judge1 am: too few checklists (48) to judge2 am: too few checklists (28) to judge3 am: too few checklists (60) to judge4 am: too few checklists (114) to judge5 am: too few checklists (1139) to judge6 am: 7.3% of 9054 checklists7 am: 8.5% of 18481 checklists8 am: 8.2% of 17525 checklists9 am: 6.8% of 15482 checklists10 am: 6.6% of 14380 checklists11 am: 5.8% of 12728 checklists12 pm: 5.7% of 11009 checklists1 pm: 5.7% of 10651 checklists2 pm: 5.3% of 10787 checklists3 pm: 5.4% of 11221 checklists4 pm: 3.7% of 11861 checklists5 pm: 3.0% of 8854 checklists6 pm: 2.5% of 6018 checklists7 pm: too few checklists (2387) to judge8 pm: too few checklists (314) to judge9 pm: too few checklists (114) to judge10 pm: too few checklists (63) to judge11 pm: too few checklists (48) 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
January6.0%7.1%7.1%7.4%
February6.1%5.6%5.0%6.3%
March4.8%6.5%6.5%6.6%
April7.1%6.2%6.0%6.6%
May5.0%4.1%4.2%3.2%
June2.0%2.3%3.0%2.5%
July3.0%3.0%4.5%3.9%
August4.4%5.4%7.0%9.0%
September9.9%8.5%9.0%7.8%
October5.9%8.3%7.4%8.5%
November5.7%6.3%5.9%6.0%
December5.4%6.3%6.4%6.6%

Neighboring states

  • Alabama: arrives late June, 7 weeks earlier than Mississippi
  • Louisiana: arrives mid March, 20 weeks earlier than Mississippi
  • Arkansas: arrives early July, 6 weeks earlier than Mississippi
  • Georgia: arrives the second week of September, 3 weeks later than Mississippi

Common questions

When do Forster's Terns arrive in Mississippi?
Forster's Terns are in Mississippi all year, but most are here in fall: numbers build from mid August, peak in the second week of September (9.2% of checklists), and fall back by mid November. In the quietest week (the second week of June) they are still on about 2.4% of checklists.
When do Forster's Terns leave Mississippi?
Forster's Terns never fully leave Mississippi: numbers fall back below half their usual rate by mid November, but some are still reported in every week, about 2.4% of checklists at the low.
When is the best time to see a Forster's Tern in Mississippi?
The Forster's Tern is reported most often in the second week of September, on about 9.2% of Mississippi checklists.
Where in Mississippi are Forster's Terns seen most often?
By county, Yalobusha County, Panola County, and Rankin County have the highest peak reporting rates for the Forster's Tern (counties with at least 200 checklists).