WhenToBird

Quiscalus mexicanus · Icteridae

When Do Great-tailed Grackles Arrive in California?

Adult female Great-tailed Grackle
Photo: Anthony Batista, CC BY 4.0 via iNaturalist

Great-tailed Grackles are in California all year, but most are here in spring: numbers build from the second week of March, peak in early May (7.0% of checklists), and fall back by mid July. In the quietest week (mid September) they are still on about 2.8% of checklists.

When to look

Numbers buildMar 8-14the second week of March
PeakMay 1-7early May
Fall back byJul 15-21mid July
FewestSep 15-21mid September

Best: early May. Here all year; numbers build from the second week of March and fall back by mid July. Peak: on about 7.0% of California checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Deccommon

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

0%2%4%6%8%Jan 1-7: 3.4% of 112336 checklistsJan 8-14: 3.2% of 85518 checklistsJan 15-21: 3.4% of 86488 checklistsJan 22-31: 3.3% of 116174 checklistsFeb 1-7: 3.5% of 75171 checklistsFeb 8-14: 3.4% of 84467 checklistsFeb 15-21: 3.6% of 105683 checklistsFeb 22-28: 4.6% of 83396 checklistsMar 1-7: 4.9% of 77470 checklistsMar 8-14: 5.2% of 75180 checklistsMar 15-21: 5.6% of 80770 checklistsMar 22-31: 5.9% of 114116 checklistsApr 1-7: 6.1% of 84057 checklistsApr 8-14: 6.3% of 83692 checklistsApr 15-21: 6.5% of 89242 checklistsApr 22-30: 7.0% of 114289 checklistsMay 1-7: 7.2% of 85728 checklistsMay 8-14: 6.7% of 91984 checklistsMay 15-21: 6.7% of 75478 checklistsMay 22-31: 6.8% of 106250 checklistsJun 1-7: 6.1% of 70051 checklistsJun 8-14: 5.9% of 67485 checklistsJun 15-21: 5.5% of 66269 checklistsJun 22-30: 5.7% of 79172 checklistsJul 1-7: 5.4% of 62877 checklistsJul 8-14: 5.3% of 60328 checklistsJul 15-21: 4.9% of 59705 checklistsJul 22-31: 4.7% of 83796 checklistsAug 1-7: 4.4% of 60215 checklistsAug 8-14: 4.1% of 60172 checklistsAug 15-21: 3.5% of 59877 checklistsAug 22-31: 3.4% of 89107 checklistsSep 1-7: 3.3% of 72000 checklistsSep 8-14: 3.0% of 71228 checklistsSep 15-21: 2.6% of 76808 checklistsSep 22-30: 2.8% of 100204 checklistsOct 1-7: 3.0% of 76571 checklistsOct 8-14: 3.6% of 80874 checklistsOct 15-21: 3.7% of 74581 checklistsOct 22-31: 3.9% of 97498 checklistsNov 1-7: 4.0% of 70851 checklistsNov 8-14: 3.7% of 72431 checklistsNov 15-21: 3.5% of 66767 checklistsNov 22-30: 3.5% of 94737 checklistsDec 1-7: 3.2% of 65393 checklistsDec 8-14: 2.9% of 67449 checklistsDec 15-21: 2.7% of 83421 checklistsDec 22-31: 3.2% 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. Imperial CountyBest the second week of June · 183 checklists that week, 24,551 in all47%
  2. Kings CountyBest late May · 99 checklists that week, 3,688 in all31%
  3. Yolo CountyBest the second week of July · 732 checklists that week, 67,424 in all26%
  4. Riverside CountyBest the second week of May · 2386 checklists that week, 113,541 in all19%
  5. Kern CountyBest mid May · 1310 checklists that week, 47,774 in all17%
  6. Merced CountyBest late May · 228 checklists that week, 13,095 in all17%

Best spots

Share of checklists at the peak
  1. Central Park LakeKern County, best mid April · 20 checklists that week, 823 in all100%
  2. Legg LakeLos Angeles County, best the second week of May · 26 checklists that week, 1,482 in all100%
  3. Galileo ParkKern County, best late May · 66 checklists that week, 508 in all99%

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

Best time of day

In California, the Great-tailed Grackle is most often listed on checklists started between 6 and 8 am (6.4% of those checklists).

0%2%4%6%8%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: 6.7% of 186053 checklists7 am: 6.2% of 444086 checklists8 am: 5.5% of 535846 checklists9 am: 4.6% of 486061 checklists10 am: 4.0% of 411130 checklists11 am: 3.6% of 325798 checklists12 pm: 3.5% of 269132 checklists1 pm: 3.5% of 244762 checklists2 pm: 3.7% of 235420 checklists3 pm: 3.7% of 232365 checklists4 pm: 3.6% of 208688 checklists5 pm: 3.9% of 146104 checklists6 pm: 3.9% 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
January3.4%3.2%3.4%3.3%
February3.5%3.4%3.6%4.6%
March4.9%5.2%5.6%5.9%
April6.1%6.3%6.5%7.0%
May7.2%6.7%6.7%6.8%
June6.1%5.9%5.5%5.7%
July5.4%5.3%4.9%4.7%
August4.4%4.1%3.5%3.4%
September3.3%3.0%2.6%2.8%
October3.0%3.6%3.7%3.9%
November4.0%3.7%3.5%3.5%
December3.2%2.9%2.7%3.2%

Neighboring states

  • Nevada: year-round, peaks late April
  • Utah: arrives late March, 2 weeks later than California
  • Arizona: year-round, peaks early November
  • New Mexico: arrives mid March, 1 week later than California

Common questions

When do Great-tailed Grackles arrive in California?
Great-tailed Grackles are in California all year, but most are here in spring: numbers build from the second week of March, peak in early May (7.0% of checklists), and fall back by mid July. In the quietest week (mid September) they are still on about 2.8% of checklists.
When do Great-tailed Grackles leave California?
Great-tailed Grackles never fully leave California: numbers fall back below half their usual rate by mid July, but some are still reported in every week, about 2.8% of checklists at the low.
When is the best time to see a Great-tailed Grackle in California?
The Great-tailed Grackle is reported most often in early May, on about 7.0% of California checklists.
Where in California are Great-tailed Grackles seen most often?
By county, Imperial County, Kings County, and Yolo County have the highest peak reporting rates for the Great-tailed Grackle (counties with at least 200 checklists).