WhenToBird

Toxostoma redivivum · Mimidae

When Do California Thrashers Arrive in California?

Adult California Thrasher
Photo: Anne Parsons, CC0 1.0 via iNaturalist

The California Thrasher is in California all year. It turns up on about 7.3% of checklists at its peak (mid April) and on 4.0% in its quietest week (late July).

When to look

PresentAll year
Peak weekApr 15-21mid April
Quietest weekJul 22-31late July

Best: mid April. Here all year. Peak: on about 7.3% of California checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Augcommon
  9. Seppeak season
  10. Octpeak season
  11. Novcommon
  12. Decpeak season

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

0%2%4%6%8%Jan 1-7: 5.3% of 112336 checklistsJan 8-14: 5.2% of 85518 checklistsJan 15-21: 5.9% of 86488 checklistsJan 22-31: 6.1% of 116174 checklistsFeb 1-7: 6.2% of 75171 checklistsFeb 8-14: 6.0% of 84467 checklistsFeb 15-21: 5.7% of 105683 checklistsFeb 22-28: 6.1% of 83396 checklistsMar 1-7: 6.4% of 77470 checklistsMar 8-14: 6.4% of 75180 checklistsMar 15-21: 6.7% of 80770 checklistsMar 22-31: 6.4% of 114116 checklistsApr 1-7: 6.9% of 84057 checklistsApr 8-14: 7.3% of 83692 checklistsApr 15-21: 7.2% of 89242 checklistsApr 22-30: 7.3% of 114289 checklistsMay 1-7: 6.9% of 85728 checklistsMay 8-14: 6.6% of 91984 checklistsMay 15-21: 6.7% of 75478 checklistsMay 22-31: 6.4% of 106250 checklistsJun 1-7: 5.7% of 70051 checklistsJun 8-14: 5.4% of 67485 checklistsJun 15-21: 4.8% of 66269 checklistsJun 22-30: 4.5% of 79172 checklistsJul 1-7: 4.5% of 62877 checklistsJul 8-14: 4.2% of 60328 checklistsJul 15-21: 4.0% of 59705 checklistsJul 22-31: 3.9% of 83796 checklistsAug 1-7: 4.1% of 60215 checklistsAug 8-14: 4.5% of 60172 checklistsAug 15-21: 4.8% of 59877 checklistsAug 22-31: 5.3% of 89107 checklistsSep 1-7: 6.1% of 72000 checklistsSep 8-14: 6.6% of 71228 checklistsSep 15-21: 6.6% of 76808 checklistsSep 22-30: 6.7% of 100204 checklistsOct 1-7: 6.2% of 76571 checklistsOct 8-14: 5.6% of 80874 checklistsOct 15-21: 4.9% of 74581 checklistsOct 22-31: 4.7% of 97498 checklistsNov 1-7: 4.4% of 70851 checklistsNov 8-14: 4.0% of 72431 checklistsNov 15-21: 3.9% of 66767 checklistsNov 22-30: 4.0% of 94737 checklistsDec 1-7: 4.5% of 65393 checklistsDec 8-14: 4.8% of 67449 checklistsDec 15-21: 5.2% of 83421 checklistsDec 22-31: 5.9% 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.

Embed this map on your site

Where in California

Best counties

Share of checklists at the peak
  1. San Benito CountyBest mid September · 526 checklists that week, 25,997 in all19%
  2. San Luis Obispo CountyBest the second week of September · 2058 checklists that week, 124,667 in all19%
  3. Santa Barbara CountyBest late May · 2732 checklists that week, 120,616 in all17%
  4. San Bernardino CountyBest late January · 2068 checklists that week, 84,093 in all16%
  5. San Diego CountyBest the second week of September · 7177 checklists that week, 405,465 in all16%
  6. Ventura CountyBest mid September · 1829 checklists that week, 94,391 in all15%

Best spots

Share of checklists at the peak
  1. Manchester Mitigation BankSan Diego County, best the second week of March · 35 checklists that week, 773 in all96%
  2. Water CanyonSan Bernardino County, best late September · 23 checklists that week, 862 in all89%
  3. Sierra Azul Open Space Preserve (northwest)Santa Cruz County, best early April · 24 checklists that week, 480 in all88%
  4. Dana Point PreserveOrange County, best the second week of September · 25 checklists that week, 817 in all86%
  5. Montaña de Oro State ParkSan Luis Obispo County, best early June · 21 checklists that week, 504 in all86%

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

Best time of day

In California, the California Thrasher is most often listed on checklists started between 6 and 8 am (10% 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: 9.8% of 444086 checklists8 am: 8.0% of 535846 checklists9 am: 6.5% of 486061 checklists10 am: 4.9% of 411130 checklists11 am: 4.0% of 325798 checklists12 pm: 3.3% of 269132 checklists1 pm: 3.1% of 244762 checklists2 pm: 3.1% of 235420 checklists3 pm: 3.3% of 232365 checklists4 pm: 3.3% of 208688 checklists5 pm: 3.8% of 146104 checklists6 pm: 3.7% 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
January5.3%5.2%5.9%6.1%
February6.2%6.0%5.7%6.1%
March6.4%6.4%6.7%6.4%
April6.9%7.3%7.2%7.3%
May6.9%6.6%6.7%6.4%
June5.7%5.4%4.8%4.5%
July4.5%4.2%4.0%3.9%
August4.1%4.5%4.8%5.3%
September6.1%6.6%6.6%6.7%
October6.2%5.6%4.9%4.7%
November4.4%4.0%3.9%4.0%
December4.5%4.8%5.2%5.9%

Common questions

When do California Thrashers arrive in California?
The California Thrasher is in California all year. It turns up on about 7.3% of checklists at its peak (mid April) and on 4.0% in its quietest week (late July).
When do California Thrashers leave California?
The California Thrasher does not leave California: it is reported all year, from 4.0% of checklists in late July to 7.3% in mid April.
When is the best time to see a California Thrasher in California?
The California Thrasher is reported most often in mid April, on about 7.3% of California checklists.
Where in California are California Thrashers seen most often?
By county, San Benito County, San Luis Obispo County, and Santa Barbara County have the highest peak reporting rates for the California Thrasher (counties with at least 200 checklists).