WhenToBird

Nannopterum auritum · Phalacrocoracidae

When Do Double-crested Cormorants Arrive in California?

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

The Double-crested Cormorant is in California all year. It turns up on about 23% of checklists at its peak (late November) and on 14% in its quietest week (the second week of June).

When to look

PresentAll year
Peak weekNov 22-30late November
Quietest weekJun 8-14the second week of June

Best: late November. Here all year. Peak: on about 23% of California checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprcommon
  5. Maycommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Seppeak season
  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: 21% of 112336 checklistsJan 8-14: 21% of 85518 checklistsJan 15-21: 21% of 86488 checklistsJan 22-31: 21% of 116174 checklistsFeb 1-7: 20% of 75171 checklistsFeb 8-14: 19% of 84467 checklistsFeb 15-21: 18% of 105683 checklistsFeb 22-28: 21% of 83396 checklistsMar 1-7: 20% of 77470 checklistsMar 8-14: 20% of 75180 checklistsMar 15-21: 19% of 80770 checklistsMar 22-31: 18% of 114116 checklistsApr 1-7: 17% of 84057 checklistsApr 8-14: 16% of 83692 checklistsApr 15-21: 16% of 89242 checklistsApr 22-30: 15% of 114289 checklistsMay 1-7: 15% of 85728 checklistsMay 8-14: 14% of 91984 checklistsMay 15-21: 14% of 75478 checklistsMay 22-31: 14% of 106250 checklistsJun 1-7: 13% of 70051 checklistsJun 8-14: 14% of 67485 checklistsJun 15-21: 14% of 66269 checklistsJun 22-30: 14% of 79172 checklistsJul 1-7: 16% of 62877 checklistsJul 8-14: 17% of 60328 checklistsJul 15-21: 18% of 59705 checklistsJul 22-31: 20% of 83796 checklistsAug 1-7: 20% of 60215 checklistsAug 8-14: 21% of 60172 checklistsAug 15-21: 21% of 59877 checklistsAug 22-31: 21% of 89107 checklistsSep 1-7: 21% of 72000 checklistsSep 8-14: 19% of 71228 checklistsSep 15-21: 19% of 76808 checklistsSep 22-30: 18% of 100204 checklistsOct 1-7: 18% of 76571 checklistsOct 8-14: 18% of 80874 checklistsOct 15-21: 19% of 74581 checklistsOct 22-31: 21% of 97498 checklistsNov 1-7: 22% of 70851 checklistsNov 8-14: 23% of 72431 checklistsNov 15-21: 23% of 66767 checklistsNov 22-30: 24% of 94737 checklistsDec 1-7: 23% of 65393 checklistsDec 8-14: 22% of 67449 checklistsDec 15-21: 19% of 83421 checklistsDec 22-31: 21% of 124993 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 California 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 California

Best counties

Share of checklists at the peak
  1. Lake CountyBest the second week of December · 217 checklists that week, 12,989 in all47%
  2. Humboldt CountyBest the second week of August · 1460 checklists that week, 95,963 in all39%
  3. Del Norte CountyBest early September · 426 checklists that week, 16,363 in all38%
  4. San Francisco CountyBest mid November · 2058 checklists that week, 130,018 in all38%
  5. Marin CountyBest mid November · 2069 checklists that week, 135,728 in all36%
  6. Alameda CountyBest mid November · 3133 checklists that week, 161,052 in all36%

Best spots

Share of checklists at the peak
  1. Apollo Community Regional ParkLos Angeles County, best early December · 29 checklists that week, 2,308 in all100%
  2. Sacramento Regional County Sanitation DistrictSacramento County, best the second week of April · 46 checklists that week, 2,065 in all99%
  3. Ellis Lake ParkContra Costa County, best early February · 27 checklists that week, 852 in all99%
  4. Levee PedwaySan Mateo County, best late November · 26 checklists that week, 499 in all98%
  5. Lake Merced ParkSan Francisco County, best mid August · 41 checklists that week, 3,011 in all98%
  6. Lake MerrittAlameda County, best the second week of November · 50 checklists that week, 2,591 in all97%

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

Best time of day

In California, the Double-crested Cormorant is most often listed on checklists started between 7 and 9 am (20% of those checklists).

0%10%20%30%12 am: too few checklists (1688) to judge1 am: too few checklists (1451) to judge2 am: too few checklists (1402) to judge3 am: too few checklists (1743) to judge4 am: too few checklists (4647) to judge5 am: too few checklists (32158) to judge6 am: 18% of 186053 checklists7 am: 20% of 444086 checklists8 am: 21% of 535846 checklists9 am: 20% of 486061 checklists10 am: 20% of 411130 checklists11 am: 19% of 325798 checklists12 pm: 19% of 269132 checklists1 pm: 20% of 244762 checklists2 pm: 20% of 235420 checklists3 pm: 19% of 232365 checklists4 pm: 17% of 208688 checklists5 pm: 15% of 146104 checklists6 pm: 13% of 96867 checklists7 pm: too few checklists (50942) to judge8 pm: too few checklists (14803) to judge9 pm: too few checklists (5561) to judge10 pm: too few checklists (3546) to judge11 pm: too few checklists (2092) 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
January21%21%21%21%
February20%19%18%21%
March20%20%19%18%
April17%16%16%15%
May15%14%14%14%
June13%14%14%14%
July16%17%18%20%
August20%21%21%21%
September21%19%19%18%
October18%18%19%21%
November22%23%23%24%
December23%22%19%21%

Neighboring states

  • Nevada: year-round, peaks late March
  • Utah: summer visitor, peaks the second week of April
  • Arizona: all year, most in winter, peaks late January
  • Oregon: all year, most in fall, peaks the second week of November

Common questions

When do Double-crested Cormorants arrive in California?
The Double-crested Cormorant is in California all year. It turns up on about 23% of checklists at its peak (late November) and on 14% in its quietest week (the second week of June).
When do Double-crested Cormorants leave California?
The Double-crested Cormorant does not leave California: it is reported all year, from 14% of checklists in the second week of June to 23% in late November.
When is the best time to see a Double-crested Cormorant in California?
The Double-crested Cormorant is reported most often in late November, on about 23% of California checklists.
Where in California are Double-crested Cormorants seen most often?
By county, Lake County, Humboldt County, and Del Norte County have the highest peak reporting rates for the Double-crested Cormorant (counties with at least 200 checklists).