WhenToBird

Nannopterum auritum · Phalacrocoracidae

When Do Double-crested Cormorants Arrive in Oklahoma?

Adult Double-crested Cormorant
Photo: jubileej, CC0 1.0 via iNaturalist

Double-crested Cormorants are in Oklahoma all year, but most are here in winter: numbers build from early October, peak in the second week of November (27% of checklists), and fall back by early February. In the quietest week (mid June) they are still on about 2.6% of checklists.

When to look

Numbers buildOct 1-7early October
PeakNov 8-14the second week of November
Fall back byFeb 1-7early February
FewestJun 15-21mid June

Best: the second week of November. Here all year; numbers build from early October and fall back by early February. Peak: on about 27% of Oklahoma checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Mayuncommon
  6. Junrare
  7. Julrare
  8. Auguncommon
  9. Sepcommon
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%10%20%30%Jan 1-7: 19% of 6087 checklistsJan 8-14: 19% of 4350 checklistsJan 15-21: 17% of 4381 checklistsJan 22-31: 16% of 6165 checklistsFeb 1-7: 16% of 4259 checklistsFeb 8-14: 12% of 4589 checklistsFeb 15-21: 11% of 7001 checklistsFeb 22-28: 16% of 4482 checklistsMar 1-7: 19% of 4724 checklistsMar 8-14: 20% of 4571 checklistsMar 15-21: 21% of 4393 checklistsMar 22-31: 22% of 7544 checklistsApr 1-7: 22% of 5967 checklistsApr 8-14: 20% of 6543 checklistsApr 15-21: 18% of 7366 checklistsApr 22-30: 13% of 10618 checklistsMay 1-7: 9.9% of 8835 checklistsMay 8-14: 7.6% of 8247 checklistsMay 15-21: 5.7% of 6081 checklistsMay 22-31: 4.3% of 7283 checklistsJun 1-7: 3.4% of 4256 checklistsJun 8-14: 2.3% of 3774 checklistsJun 15-21: 2.5% of 3541 checklistsJun 22-30: 2.9% of 4159 checklistsJul 1-7: 2.8% of 3209 checklistsJul 8-14: 3.1% of 2916 checklistsJul 15-21: 2.9% of 2861 checklistsJul 22-31: 3.4% of 4146 checklistsAug 1-7: 5.2% of 3043 checklistsAug 8-14: 4.3% of 2839 checklistsAug 15-21: 5.3% of 3014 checklistsAug 22-31: 5.0% of 4759 checklistsSep 1-7: 6.0% of 3861 checklistsSep 8-14: 6.1% of 3748 checklistsSep 15-21: 7.6% of 3569 checklistsSep 22-30: 12% of 4830 checklistsOct 1-7: 17% of 3809 checklistsOct 8-14: 20% of 4142 checklistsOct 15-21: 25% of 3705 checklistsOct 22-31: 25% of 4738 checklistsNov 1-7: 27% of 3823 checklistsNov 8-14: 27% of 3849 checklistsNov 15-21: 26% of 3722 checklistsNov 22-30: 26% of 4795 checklistsDec 1-7: 23% of 3324 checklistsDec 8-14: 23% of 3574 checklistsDec 15-21: 20% of 3884 checklistsDec 22-31: 19% of 5774 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 Oklahoma 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 Oklahoma

Best counties

Share of checklists at the peak
  1. Blaine CountyBest the second week of November · 28 checklists that week, 732 in all64%
  2. Choctaw CountyBest early January · 17 checklists that week, 844 in all55%
  3. Marshall CountyBest mid March · 15 checklists that week, 590 in all53%
  4. Jefferson CountyBest the second week of November · 19 checklists that week, 620 in all52%
  5. Alfalfa CountyBest early August · 46 checklists that week, 3,843 in all50%
  6. Creek CountyBest late October · 59 checklists that week, 2,822 in all50%

Best spots

Share of checklists at the peak
  1. Spring Creek ParkOklahoma County, best late November · 21 checklists that week, 749 in all98%
  2. Lincoln ParkOklahoma County, best early December · 20 checklists that week, 818 in all95%
  3. Lake YaholaTulsa County, best the second week of November · 32 checklists that week, 1,291 in all92%
  4. Lake Thunderbird State ParkCleveland County, best the second week of April · 40 checklists that week, 824 in all92%
  5. CLO LandsPayne County, best mid November · 29 checklists that week, 1,208 in all90%
  6. Edmond ParkOklahoma County, best late October · 26 checklists that week, 792 in all89%

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

Best time of day

In Oklahoma, the Double-crested Cormorant is most often listed on checklists started between 2 and 4 pm (17% of those checklists).

0%5%10%15%20%12 am: too few checklists (91) to judge1 am: too few checklists (65) to judge2 am: too few checklists (73) to judge3 am: too few checklists (73) to judge4 am: too few checklists (100) to judge5 am: too few checklists (647) to judge6 am: 9.3% of 8353 checklists7 am: 14% of 24509 checklists8 am: 16% of 27848 checklists9 am: 15% of 25316 checklists10 am: 15% of 21161 checklists11 am: 16% of 18730 checklists12 pm: 14% of 16097 checklists1 pm: 16% of 14028 checklists2 pm: 16% of 13599 checklists3 pm: 17% of 14228 checklists4 pm: 15% of 14597 checklists5 pm: 11% of 12125 checklists6 pm: 7.8% of 9337 checklists7 pm: 3.7% of 6944 checklists8 pm: too few checklists (2403) to judge9 pm: too few checklists (459) to judge10 pm: too few checklists (226) 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
January19%19%17%16%
February16%12%11%16%
March19%20%21%22%
April22%20%18%13%
May9.9%7.6%5.7%4.3%
June3.4%2.3%2.5%2.9%
July2.8%3.1%2.9%3.4%
August5.2%4.3%5.3%5.0%
September6.0%6.1%7.6%12%
October17%20%25%25%
November27%27%26%26%
December23%23%20%19%

Neighboring states

  • Kansas: arrives mid July, 10 weeks earlier than Oklahoma
  • Arkansas: arrives the second week of July, 11 weeks earlier than Oklahoma
  • Missouri: arrives mid February, 18 weeks later than Oklahoma
  • Nebraska: arrives early March, 20 weeks later than Oklahoma

Common questions

When do Double-crested Cormorants arrive in Oklahoma?
Double-crested Cormorants are in Oklahoma all year, but most are here in winter: numbers build from early October, peak in the second week of November (27% of checklists), and fall back by early February. In the quietest week (mid June) they are still on about 2.6% of checklists.
When do Double-crested Cormorants leave Oklahoma?
Double-crested Cormorants never fully leave Oklahoma: numbers fall back below half their usual rate by early February, but some are still reported in every week, about 2.6% of checklists at the low.
When is the best time to see a Double-crested Cormorant in Oklahoma?
The Double-crested Cormorant is reported most often in the second week of November, on about 27% of Oklahoma checklists.
Where in Oklahoma are Double-crested Cormorants seen most often?
By county, Blaine County, Choctaw County, and Marshall County have the highest peak reporting rates for the Double-crested Cormorant (counties with at least 200 checklists).