WhenToBird

Molothrus ater · Icteridae

When Do Brown-headed Cowbirds Arrive in Alabama?

Adult female Brown-headed Cowbird
Photo: Nicole, CC BY 4.0 via iNaturalist

Brown-headed Cowbirds are in Alabama all year, but most are here in spring: numbers build from early March, peak in early May (26% of checklists), and fall back by early July. In the quietest week (the second week of September) they are still on about 3.5% of checklists.

When to look

Numbers buildMar 1-7early March
PeakMay 1-7early May
Fall back byJul 1-7early July
FewestSep 8-14the second week of September

Best: early May. Here all year; numbers build from early March and fall back by early July. Peak: on about 26% of Alabama checklists.

  1. Januncommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Auguncommon
  9. Sepuncommon
  10. Octuncommon
  11. Novuncommon
  12. Decuncommon

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

0%10%20%30%Jan 1-7: 7.0% of 8642 checklistsJan 8-14: 8.3% of 6607 checklistsJan 15-21: 8.8% of 6680 checklistsJan 22-31: 8.6% of 9008 checklistsFeb 1-7: 11% of 6642 checklistsFeb 8-14: 11% of 7568 checklistsFeb 15-21: 12% of 9929 checklistsFeb 22-28: 15% of 6490 checklistsMar 1-7: 16% of 6458 checklistsMar 8-14: 19% of 6570 checklistsMar 15-21: 20% of 6773 checklistsMar 22-31: 23% of 10830 checklistsApr 1-7: 24% of 8995 checklistsApr 8-14: 26% of 10390 checklistsApr 15-21: 25% of 12700 checklistsApr 22-30: 26% of 14225 checklistsMay 1-7: 27% of 9140 checklistsMay 8-14: 26% of 8111 checklistsMay 15-21: 25% of 6353 checklistsMay 22-31: 23% of 8318 checklistsJun 1-7: 23% of 5231 checklistsJun 8-14: 22% of 4757 checklistsJun 15-21: 20% of 4646 checklistsJun 22-30: 18% of 5740 checklistsJul 1-7: 16% of 4694 checklistsJul 8-14: 11% of 4178 checklistsJul 15-21: 7.1% of 4109 checklistsJul 22-31: 5.3% of 6000 checklistsAug 1-7: 4.9% of 4666 checklistsAug 8-14: 4.5% of 4468 checklistsAug 15-21: 4.5% of 4474 checklistsAug 22-31: 4.2% of 6494 checklistsSep 1-7: 3.5% of 5434 checklistsSep 8-14: 3.2% of 5216 checklistsSep 15-21: 3.7% of 5162 checklistsSep 22-30: 5.4% of 7474 checklistsOct 1-7: 6.3% of 6916 checklistsOct 8-14: 6.7% of 7332 checklistsOct 15-21: 7.6% of 6038 checklistsOct 22-31: 8.2% of 7071 checklistsNov 1-7: 7.3% of 5207 checklistsNov 8-14: 6.3% of 4883 checklistsNov 15-21: 7.4% of 5122 checklistsNov 22-30: 5.9% of 7130 checklistsDec 1-7: 6.0% of 4897 checklistsDec 8-14: 5.8% of 4738 checklistsDec 15-21: 5.9% of 5321 checklistsDec 22-31: 6.2% 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. Marengo CountyBest the second week of March · 49 checklists that week, 2,453 in all77%
  2. Chambers CountyBest the second week of April · 52 checklists that week, 2,519 in all63%
  3. Houston CountyBest early March · 146 checklists that week, 6,424 in all62%
  4. Geneva CountyBest early April · 59 checklists that week, 3,203 in all60%
  5. Perry CountyBest early June · 32 checklists that week, 1,066 in all57%
  6. Sumter CountyBest early June · 16 checklists that week, 782 in all55%

Best spots

Share of checklists at the peak
  1. Goldsmith-Schiffman Wildlife SanctuaryMadison County, best the second week of April · 20 checklists that week, 251 in all74%
  2. Swan Creek Wildlife Management AreaLimestone County, best mid April · 26 checklists that week, 696 in all72%
  3. Flint Creek IslandMorgan County, best the second week of May · 24 checklists that week, 2,196 in all68%
  4. Monte Sano State ParkMadison County, best the second week of May · 79 checklists that week, 1,590 in all67%

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

Best time of day

In Alabama, the Brown-headed Cowbird is most often listed on checklists started between 6 and 8 am (21% of those checklists).

0%10%20%30%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: 24% of 26677 checklists7 am: 19% of 42599 checklists8 am: 16% of 39919 checklists9 am: 14% of 34699 checklists10 am: 12% of 28551 checklists11 am: 10% of 23505 checklists12 pm: 10% of 20345 checklists1 pm: 9.8% of 18964 checklists2 pm: 8.9% of 20110 checklists3 pm: 9.4% of 20685 checklists4 pm: 10% of 19041 checklists5 pm: 11% of 13807 checklists6 pm: 10% 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
January7.0%8.3%8.8%8.6%
February11%11%12%15%
March16%19%20%23%
April24%26%25%26%
May27%26%25%23%
June23%22%20%18%
July16%11%7.1%5.3%
August4.9%4.5%4.5%4.2%
September3.5%3.2%3.7%5.4%
October6.3%6.7%7.6%8.2%
November7.3%6.3%7.4%5.9%
December6.0%5.8%5.9%6.2%

Neighboring states

  • Mississippi: arrives the second week of March, 1 week later than Alabama
  • Georgia: arrives mid March, 2 weeks later than Alabama
  • Tennessee: arrives mid March, 2 weeks later than Alabama
  • Louisiana: arrives early March, in the same week than Alabama

Common questions

When do Brown-headed Cowbirds arrive in Alabama?
Brown-headed Cowbirds are in Alabama all year, but most are here in spring: numbers build from early March, peak in early May (26% of checklists), and fall back by early July. In the quietest week (the second week of September) they are still on about 3.5% of checklists.
When do Brown-headed Cowbirds leave Alabama?
Brown-headed Cowbirds never fully leave Alabama: numbers fall back below half their usual rate by early July, but some are still reported in every week, about 3.5% of checklists at the low.
When is the best time to see a Brown-headed Cowbird in Alabama?
The Brown-headed Cowbird is reported most often in early May, on about 26% of Alabama checklists.
Where in Alabama are Brown-headed Cowbirds seen most often?
By county, Marengo County, Chambers County, and Houston County have the highest peak reporting rates for the Brown-headed Cowbird (counties with at least 200 checklists).