WhenToBird

Nannopterum auritum · Phalacrocoracidae

When Do Double-crested Cormorants Arrive in Arizona?

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

Double-crested Cormorants are in Arizona all year, but most are here in winter: numbers build from the second week of October, peak in late January (7.4% of checklists), and fall back by late March. In the quietest week (late May) they are still on about 2.2% of checklists.

When to look

Numbers buildOct 8-14the second week of October
PeakJan 22-31late January
Fall back byMar 22-31late March
FewestMay 22-31late May

Best: late January. Here all year; numbers build from the second week of October and fall back by late March. Peak: on about 7.4% of Arizona checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprcommon
  5. Mayuncommon
  6. Jununcommon
  7. Juluncommon
  8. Auguncommon
  9. Sepcommon
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%2%4%6%8%Jan 1-7: 6.2% of 34758 checklistsJan 8-14: 6.5% of 29835 checklistsJan 15-21: 7.8% of 29279 checklistsJan 22-31: 7.1% of 39716 checklistsFeb 1-7: 7.3% of 27299 checklistsFeb 8-14: 7.2% of 28703 checklistsFeb 15-21: 6.9% of 35357 checklistsFeb 22-28: 7.1% of 29889 checklistsMar 1-7: 7.1% of 29932 checklistsMar 8-14: 6.7% of 32982 checklistsMar 15-21: 6.2% of 34731 checklistsMar 22-31: 5.3% of 50213 checklistsApr 1-7: 4.4% of 35788 checklistsApr 8-14: 3.9% of 38087 checklistsApr 15-21: 3.0% of 41520 checklistsApr 22-30: 2.8% of 55218 checklistsMay 1-7: 2.5% of 39688 checklistsMay 8-14: 2.5% of 39398 checklistsMay 15-21: 2.1% of 29562 checklistsMay 22-31: 2.1% of 36774 checklistsJun 1-7: 2.4% of 21313 checklistsJun 8-14: 2.3% of 19129 checklistsJun 15-21: 2.4% of 17922 checklistsJun 22-30: 2.7% of 21188 checklistsJul 1-7: 3.0% of 17325 checklistsJul 8-14: 2.5% of 16463 checklistsJul 15-21: 2.7% of 18642 checklistsJul 22-31: 2.2% of 31215 checklistsAug 1-7: 2.4% of 28163 checklistsAug 8-14: 2.0% of 31329 checklistsAug 15-21: 2.4% of 23878 checklistsAug 22-31: 2.9% of 28508 checklistsSep 1-7: 3.1% of 20878 checklistsSep 8-14: 3.3% of 19671 checklistsSep 15-21: 3.3% of 19859 checklistsSep 22-30: 3.6% of 25179 checklistsOct 1-7: 4.4% of 19420 checklistsOct 8-14: 5.3% of 21925 checklistsOct 15-21: 6.0% of 20995 checklistsOct 22-31: 6.8% of 29258 checklistsNov 1-7: 6.5% of 21269 checklistsNov 8-14: 6.7% of 22753 checklistsNov 15-21: 7.8% of 21982 checklistsNov 22-30: 7.4% of 29475 checklistsDec 1-7: 6.8% of 20810 checklistsDec 8-14: 6.1% of 22229 checklistsDec 15-21: 5.7% of 25148 checklistsDec 22-31: 6.4% of 39567 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 Arizona 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 Arizona

Best counties

Share of checklists at the peak
  1. Yuma CountyBest late January · 581 checklists that week, 14,687 in all38%
  2. La Paz CountyBest the second week of November · 185 checklists that week, 7,279 in all30%
  3. Mohave CountyBest late January · 573 checklists that week, 18,083 in all22%
  4. Maricopa CountyBest late January · 9545 checklists that week, 269,896 in all19%
  5. Navajo CountyBest the second week of July · 415 checklists that week, 18,838 in all17%
  6. Gila CountyBest mid January · 187 checklists that week, 14,834 in all16%

Best spots

Share of checklists at the peak
  1. Thunderbird ParkMaricopa County, best the second week of December · 21 checklists that week, 840 in all87%
  2. Chaparral ParkMaricopa County, best late December · 29 checklists that week, 887 in all85%
  3. Willow Creek ReservoirYavapai County, best late June · 46 checklists that week, 2,613 in all83%

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

Best time of day

In Arizona, the Double-crested Cormorant is most often listed on checklists started between 8 and 10 am (5.4% of those checklists).

0%2%4%6%12 am: too few checklists (488) to judge1 am: too few checklists (503) to judge2 am: too few checklists (489) to judge3 am: too few checklists (735) to judge4 am: too few checklists (4115) to judge5 am: 3.8% of 38350 checklists6 am: 4.2% of 118786 checklists7 am: 5.2% of 183415 checklists8 am: 5.5% of 187346 checklists9 am: 5.2% of 151342 checklists10 am: 4.9% of 124522 checklists11 am: 4.8% of 97088 checklists12 pm: 4.7% of 78110 checklists1 pm: 5.0% of 73059 checklists2 pm: 5.0% of 68912 checklists3 pm: 5.0% of 68060 checklists4 pm: 4.4% of 69387 checklists5 pm: 3.4% of 52951 checklists6 pm: 1.9% of 31061 checklists7 pm: too few checklists (16076) to judge8 pm: too few checklists (5352) to judge9 pm: too few checklists (2369) to judge10 pm: too few checklists (1100) to judge11 pm: too few checklists (604) 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
January6.2%6.5%7.8%7.1%
February7.3%7.2%6.9%7.1%
March7.1%6.7%6.2%5.3%
April4.4%3.9%3.0%2.8%
May2.5%2.5%2.1%2.1%
June2.4%2.3%2.4%2.7%
July3.0%2.5%2.7%2.2%
August2.4%2.0%2.4%2.9%
September3.1%3.3%3.3%3.6%
October4.4%5.3%6.0%6.8%
November6.5%6.7%7.8%7.4%
December6.8%6.1%5.7%6.4%

Neighboring states

  • New Mexico: year-round, peaks early October
  • Nevada: year-round, peaks late March
  • Utah: arrives early January, 11 weeks later than Arizona
  • California: year-round, peaks late November

Common questions

When do Double-crested Cormorants arrive in Arizona?
Double-crested Cormorants are in Arizona all year, but most are here in winter: numbers build from the second week of October, peak in late January (7.4% of checklists), and fall back by late March. In the quietest week (late May) they are still on about 2.2% of checklists.
When do Double-crested Cormorants leave Arizona?
Double-crested Cormorants never fully leave Arizona: numbers fall back below half their usual rate by late March, but some are still reported in every week, about 2.2% of checklists at the low.
When is the best time to see a Double-crested Cormorant in Arizona?
The Double-crested Cormorant is reported most often in late January, on about 7.4% of Arizona checklists.
Where in Arizona are Double-crested Cormorants seen most often?
By county, Yuma County, La Paz County, and Mohave County have the highest peak reporting rates for the Double-crested Cormorant (counties with at least 200 checklists).