WhenToBird

Sterna hirundo · Laridae

When Do Common Terns Arrive in Alabama?

Adult Common Tern
Photo: Сергей Неклюдов, CC BY 4.0 via iNaturalist

Common Terns arrive in Alabama in late April, peak in early September (1.5% of checklists), and most are gone by the second week of October.

When to look

First arrivalsApr 22-30late April
Common byApr 22-30late April
PeakSep 1-7early September
Most gone byOct 8-14the second week of October

Best: early September. First arrivals late April; most are gone by the second week of October. Peak: on about 1.5% of Alabama checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marrare
  4. Apruncommon
  5. Maycommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Seppeak season
  10. Octcommon
  11. Novrare
  12. Decnot usually seen

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

0%0.5%1%1.5%2%Jan 1-7: 0% of 8642 checklistsJan 8-14: 0.1% of 6607 checklistsJan 15-21: 0% of 6680 checklistsJan 22-31: 0% of 9008 checklistsFeb 1-7: 0.1% of 6642 checklistsFeb 8-14: 0% of 7568 checklistsFeb 15-21: 0.1% of 9929 checklistsFeb 22-28: 0.1% of 6490 checklistsMar 1-7: 0.1% of 6458 checklistsMar 8-14: 0% of 6570 checklistsMar 15-21: 0.1% of 6773 checklistsMar 22-31: 0.1% of 10830 checklistsApr 1-7: 0.1% of 8995 checklistsApr 8-14: 0.1% of 10390 checklistsApr 15-21: 0.5% of 12700 checklistsApr 22-30: 0.4% of 14225 checklistsMay 1-7: 0.6% of 9140 checklistsMay 8-14: 0.8% of 8111 checklistsMay 15-21: 0.9% of 6353 checklistsMay 22-31: 0.9% of 8318 checklistsJun 1-7: 0.7% of 5231 checklistsJun 8-14: 0.6% of 4757 checklistsJun 15-21: 0.9% of 4646 checklistsJun 22-30: 0.9% of 5740 checklistsJul 1-7: 0.8% of 4694 checklistsJul 8-14: 1.0% of 4178 checklistsJul 15-21: 1.2% of 4109 checklistsJul 22-31: 1.5% of 6000 checklistsAug 1-7: 1.3% of 4666 checklistsAug 8-14: 1.3% of 4468 checklistsAug 15-21: 1.0% of 4474 checklistsAug 22-31: 1.3% of 6494 checklistsSep 1-7: 1.6% of 5434 checklistsSep 8-14: 1.5% of 5216 checklistsSep 15-21: 1.0% of 5162 checklistsSep 22-30: 0.8% of 7474 checklistsOct 1-7: 0.6% of 6916 checklistsOct 8-14: 0.7% of 7332 checklistsOct 15-21: 0.3% of 6038 checklistsOct 22-31: 0.3% of 7071 checklistsNov 1-7: 0.1% of 5207 checklistsNov 8-14: 0% of 4883 checklistsNov 15-21: 0.1% of 5122 checklistsNov 22-30: 0.1% of 7130 checklistsDec 1-7: 0.1% of 4897 checklistsDec 8-14: 0% of 4738 checklistsDec 15-21: 0% of 5321 checklistsDec 22-31: 0.1% of 9158 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 Alabama 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 Alabama

Best counties

Share of checklists at the peak
  1. Mobile CountyBest early August · 248 checklists that week, 34,270 in all13%
  2. Lawrence CountyBest mid September · 22 checklists that week, 1,969 in all10%
  3. Chambers CountyBest mid September · 44 checklists that week, 2,519 in all6.4%
  4. Baldwin CountyBest late July · 854 checklists that week, 54,971 in all4.1%
  5. Marshall CountyBest early October · 91 checklists that week, 5,647 in all2.8%
  6. Colbert CountyBest late April · 163 checklists that week, 4,794 in all1.3%

Best spots

Share of checklists at the peak
  1. Wheeler Reservoir Retained LandLawrence County, best the second week of September · 21 checklists that week, 841 in all13%
  2. Dauphin Island Public BeachMobile County, best late May · 22 checklists that week, 1,054 in all11%
  3. Village PointBaldwin County, best late July · 78 checklists that week, 3,600 in all8.3%
  4. Beulah BayLimestone County, best the second week of May · 24 checklists that week, 373 in all7.8%

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

Best time of day

In Alabama, the Common Tern is most often listed on checklists started between 6 and 8 am (0.7% of those checklists).

0%0.5%1%12 am: too few checklists (109) to judge1 am: too few checklists (111) to judge2 am: too few checklists (112) to judge3 am: too few checklists (143) to judge4 am: too few checklists (303) to judge5 am: too few checklists (4125) to judge6 am: 1.0% of 26677 checklists7 am: 0.6% of 42599 checklists8 am: 0.4% of 39919 checklists9 am: 0.4% of 34699 checklists10 am: 0.4% of 28551 checklists11 am: 0.2% of 23505 checklists12 pm: 0.3% of 20345 checklists1 pm: 0.3% of 18964 checklists2 pm: 0.4% of 20110 checklists3 pm: 0.4% of 20685 checklists4 pm: 0.3% of 19041 checklists5 pm: 0.4% of 13807 checklists6 pm: 0.5% of 8507 checklists7 pm: too few checklists (3367) to judge8 pm: too few checklists (637) to judge9 pm: too few checklists (295) to judge10 pm: too few checklists (233) to judge11 pm: too few checklists (141) 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%0.1%0%0%
February0.1%0%0.1%0.1%
March0.1%0%0.1%0.1%
April0.1%0.1%0.5%0.4%
May0.6%0.8%0.9%0.9%
June0.7%0.6%0.9%0.9%
July0.8%1.0%1.2%1.5%
August1.3%1.3%1.0%1.3%
September1.6%1.5%1.0%0.8%
October0.6%0.7%0.3%0.3%
November0.1%0%0.1%0.1%
December0.1%0%0%0.1%

Neighboring states

  • Mississippi: arrives the second week of May, 2 weeks later than Alabama
  • Louisiana: arrives late March, 4 weeks earlier than Alabama
  • South Carolina: arrives late March, 4 weeks earlier than Alabama
  • Florida: arrives mid May, 3 weeks later than Alabama

Common questions

When do Common Terns arrive in Alabama?
Common Terns arrive in Alabama in late April, peak in early September (1.5% of checklists), and most are gone by the second week of October.
When do Common Terns leave Alabama?
Most Common Terns have left Alabama by the second week of October, when reports fall below half their usual rate.
When is the best time to see a Common Tern in Alabama?
The Common Tern is reported most often in early September, on about 1.5% of Alabama checklists.
Where in Alabama are Common Terns seen most often?
By county, Mobile County, Lawrence County, and Chambers County have the highest peak reporting rates for the Common Tern (counties with at least 200 checklists).