WhenToBird

Euphagus cyanocephalus · Icteridae

When Do Brewer's Blackbirds Arrive in California?

Adult Brewer's Blackbird
Photo: William Harmon, CC BY 4.0 via iNaturalist

The Brewer's Blackbird is in California all year. It turns up on about 13% of checklists at its peak (the second week of June) and on 8.5% in its quietest week (the second week of February).

When to look

PresentAll year
Peak weekJun 8-14the second week of June
Quietest weekFeb 8-14the second week of February

Best: the second week of June. Here all year. Peak: on about 13% of California checklists.

  1. Janpeak season
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%5%10%15%Jan 1-7: 10% of 112336 checklistsJan 8-14: 9.8% of 85518 checklistsJan 15-21: 10% of 86488 checklistsJan 22-31: 9.6% of 116174 checklistsFeb 1-7: 8.9% of 75171 checklistsFeb 8-14: 8.6% of 84467 checklistsFeb 15-21: 8.1% of 105683 checklistsFeb 22-28: 9.1% of 83396 checklistsMar 1-7: 9.1% of 77470 checklistsMar 8-14: 9.3% of 75180 checklistsMar 15-21: 9.9% of 80770 checklistsMar 22-31: 10% of 114116 checklistsApr 1-7: 11% of 84057 checklistsApr 8-14: 11% of 83692 checklistsApr 15-21: 11% of 89242 checklistsApr 22-30: 11% of 114289 checklistsMay 1-7: 12% of 85728 checklistsMay 8-14: 12% of 91984 checklistsMay 15-21: 12% of 75478 checklistsMay 22-31: 13% of 106250 checklistsJun 1-7: 13% of 70051 checklistsJun 8-14: 13% of 67485 checklistsJun 15-21: 13% of 66269 checklistsJun 22-30: 12% of 79172 checklistsJul 1-7: 11% of 62877 checklistsJul 8-14: 9.7% of 60328 checklistsJul 15-21: 9.2% of 59705 checklistsJul 22-31: 9.1% of 83796 checklistsAug 1-7: 8.6% of 60215 checklistsAug 8-14: 9.1% of 60172 checklistsAug 15-21: 8.9% of 59877 checklistsAug 22-31: 9.3% of 89107 checklistsSep 1-7: 9.5% of 72000 checklistsSep 8-14: 10% of 71228 checklistsSep 15-21: 11% of 76808 checklistsSep 22-30: 12% of 100204 checklistsOct 1-7: 12% of 76571 checklistsOct 8-14: 12% of 80874 checklistsOct 15-21: 12% of 74581 checklistsOct 22-31: 12% of 97498 checklistsNov 1-7: 12% of 70851 checklistsNov 8-14: 11% of 72431 checklistsNov 15-21: 11% of 66767 checklistsNov 22-30: 11% of 94737 checklistsDec 1-7: 10% of 65393 checklistsDec 8-14: 9.9% of 67449 checklistsDec 15-21: 9.7% of 83421 checklistsDec 22-31: 9.4% 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. Kings CountyBest late September · 123 checklists that week, 3,688 in all52%
  2. Mono CountyBest late April · 1077 checklists that week, 38,666 in all45%
  3. Colusa CountyBest late September · 86 checklists that week, 7,653 in all44%
  4. Alpine CountyBest early May · 60 checklists that week, 6,013 in all44%
  5. Plumas CountyBest the second week of June · 1166 checklists that week, 24,629 in all42%
  6. Modoc CountyBest early June · 374 checklists that week, 6,138 in all41%

Best spots

Share of checklists at the peak
  1. Apollo Community Regional ParkLos Angeles County, best mid July · 23 checklists that week, 2,308 in all97%
  2. Jack O'Conell ParkSanta Barbara County, best late January · 24 checklists that week, 287 in all93%
  3. Elkhorn Slough Ecological Reserve (west)Monterey County, best the second week of January · 27 checklists that week, 2,097 in all93%
  4. Mono Basin National Scenic AreaMono County, best mid September · 84 checklists that week, 1,309 in all91%

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

Best time of day

In California, the Brewer's Blackbird is most often listed on checklists started between 6 and 8 am (11% of those checklists).

0%5%10%15%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: 11% of 186053 checklists7 am: 12% of 444086 checklists8 am: 11% of 535846 checklists9 am: 11% of 486061 checklists10 am: 11% of 411130 checklists11 am: 10% of 325798 checklists12 pm: 10% of 269132 checklists1 pm: 11% of 244762 checklists2 pm: 11% of 235420 checklists3 pm: 11% of 232365 checklists4 pm: 9.6% of 208688 checklists5 pm: 9.1% of 146104 checklists6 pm: 8.5% 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
January10%9.8%10%9.6%
February8.9%8.6%8.1%9.1%
March9.1%9.3%9.9%10%
April11%11%11%11%
May12%12%12%13%
June13%13%13%12%
July11%9.7%9.2%9.1%
August8.6%9.1%8.9%9.3%
September9.5%10%11%12%
October12%12%12%12%
November12%11%11%11%
December10%9.9%9.7%9.4%

Neighboring states

  • Nevada: year-round, peaks late June
  • Utah: all year, most in summer, peaks the second week of May
  • Arizona: winter visitor, peaks the second week of October
  • Oregon: all year, most in spring, peaks late May

Common questions

When do Brewer's Blackbirds arrive in California?
The Brewer's Blackbird is in California all year. It turns up on about 13% of checklists at its peak (the second week of June) and on 8.5% in its quietest week (the second week of February).
When do Brewer's Blackbirds leave California?
The Brewer's Blackbird does not leave California: it is reported all year, from 8.5% of checklists in the second week of February to 13% in the second week of June.
When is the best time to see a Brewer's Blackbird in California?
The Brewer's Blackbird is reported most often in the second week of June, on about 13% of California checklists.
Where in California are Brewer's Blackbirds seen most often?
By county, Kings County, Mono County, and Colusa County have the highest peak reporting rates for the Brewer's Blackbird (counties with at least 200 checklists).