WhenToBird

Quiscalus mexicanus · Icteridae

When Do Great-tailed Grackles Arrive in Utah?

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

Great-tailed Grackles are in Utah all year, but most are here in spring: numbers build from late March, peak in late April (7.9% of checklists), and fall back by early June. In the quietest week (early October) they are still on about 2.7% of checklists.

When to look

Numbers buildMar 22-31late March
PeakApr 22-30late April
Fall back byJun 1-7early June
FewestOct 1-7early October

Best: late April. Here all year; numbers build from late March and fall back by early June. Peak: on about 7.9% of Utah checklists.

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

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

0%5%10%Jan 1-7: 3.2% of 10857 checklistsJan 8-14: 2.9% of 8333 checklistsJan 15-21: 3.4% of 8360 checklistsJan 22-31: 3.3% of 10516 checklistsFeb 1-7: 2.8% of 7416 checklistsFeb 8-14: 2.6% of 8082 checklistsFeb 15-21: 2.9% of 9643 checklistsFeb 22-28: 3.2% of 7960 checklistsMar 1-7: 4.2% of 7998 checklistsMar 8-14: 3.9% of 8581 checklistsMar 15-21: 5.2% of 8637 checklistsMar 22-31: 6.2% of 13006 checklistsApr 1-7: 7.0% of 10562 checklistsApr 8-14: 7.4% of 11694 checklistsApr 15-21: 7.6% of 11382 checklistsApr 22-30: 8.1% of 16626 checklistsMay 1-7: 7.7% of 13523 checklistsMay 8-14: 7.5% of 14714 checklistsMay 15-21: 7.5% of 13711 checklistsMay 22-31: 5.9% of 16546 checklistsJun 1-7: 5.2% of 10284 checklistsJun 8-14: 4.9% of 9530 checklistsJun 15-21: 4.5% of 8854 checklistsJun 22-30: 3.8% of 10566 checklistsJul 1-7: 3.6% of 7987 checklistsJul 8-14: 3.7% of 7471 checklistsJul 15-21: 3.8% of 7240 checklistsJul 22-31: 3.4% of 9329 checklistsAug 1-7: 3.1% of 6521 checklistsAug 8-14: 3.5% of 6423 checklistsAug 15-21: 2.8% of 6208 checklistsAug 22-31: 3.1% of 9089 checklistsSep 1-7: 3.3% of 7081 checklistsSep 8-14: 3.2% of 7306 checklistsSep 15-21: 3.0% of 7208 checklistsSep 22-30: 2.6% of 8876 checklistsOct 1-7: 2.8% of 7265 checklistsOct 8-14: 2.8% of 7226 checklistsOct 15-21: 3.5% of 7007 checklistsOct 22-31: 3.6% of 8443 checklistsNov 1-7: 4.3% of 6711 checklistsNov 8-14: 3.8% of 6290 checklistsNov 15-21: 4.3% of 6169 checklistsNov 22-30: 4.6% of 8228 checklistsDec 1-7: 3.4% of 6011 checklistsDec 8-14: 2.6% of 6044 checklistsDec 15-21: 2.6% of 6721 checklistsDec 22-31: 3.3% of 9982 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 Utah 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 Utah

Best counties

Share of checklists at the peak
  1. Box Elder CountyBest mid May · 400 checklists that week, 9,867 in all20%
  2. Iron CountyBest late April · 414 checklists that week, 8,774 in all20%
  3. Washington CountyBest late April · 2606 checklists that week, 43,893 in all19%
  4. Tooele CountyBest early January · 37 checklists that week, 4,788 in all14%
  5. Davis CountyBest the second week of May · 1482 checklists that week, 39,952 in all13%
  6. Utah CountyBest late May · 2346 checklists that week, 70,971 in all10%

Best spots

Share of checklists at the peak
  1. Springs ParkWashington County, best late May · 22 checklists that week, 795 in all96%
  2. Sullivan Virgin River Soccer ParkWashington County, best late January · 32 checklists that week, 411 in all90%
  3. Ivins ReservoirWashington County, best late April · 35 checklists that week, 1,043 in all90%
  4. Harrisburg CanyonWashington County, best late March · 20 checklists that week, 676 in all87%

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

Best time of day

In Utah, the Great-tailed Grackle is most often listed on checklists started between 6 and 8 am (6.3% of those checklists).

0%2%4%6%8%12 am: too few checklists (242) to judge1 am: too few checklists (178) to judge2 am: too few checklists (169) to judge3 am: too few checklists (162) to judge4 am: too few checklists (284) to judge5 am: too few checklists (1984) to judge6 am: 6.4% of 11714 checklists7 am: 6.2% of 33209 checklists8 am: 5.2% of 46944 checklists9 am: 4.8% of 46290 checklists10 am: 4.5% of 43144 checklists11 am: 4.2% of 36893 checklists12 pm: 4.1% of 32758 checklists1 pm: 3.9% of 30142 checklists2 pm: 4.1% of 29414 checklists3 pm: 4.2% of 29491 checklists4 pm: 4.4% of 29154 checklists5 pm: 4.6% of 22256 checklists6 pm: 4.4% of 17383 checklists7 pm: 4.1% of 13099 checklists8 pm: too few checklists (6647) to judge9 pm: too few checklists (1753) to judge10 pm: too few checklists (599) to judge11 pm: too few checklists (307) 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
January3.2%2.9%3.4%3.3%
February2.8%2.6%2.9%3.2%
March4.2%3.9%5.2%6.2%
April7.0%7.4%7.6%8.1%
May7.7%7.5%7.5%5.9%
June5.2%4.9%4.5%3.8%
July3.6%3.7%3.8%3.4%
August3.1%3.5%2.8%3.1%
September3.3%3.2%3.0%2.6%
October2.8%2.8%3.5%3.6%
November4.3%3.8%4.3%4.6%
December3.4%2.6%2.6%3.3%

Neighboring states

  • Wyoming: arrives late March, in the same week than Utah
  • Nevada: year-round, peaks late April
  • Colorado: arrives the second week of March, 2 weeks earlier than Utah
  • New Mexico: arrives mid March, 1 week earlier than Utah

Common questions

When do Great-tailed Grackles arrive in Utah?
Great-tailed Grackles are in Utah all year, but most are here in spring: numbers build from late March, peak in late April (7.9% of checklists), and fall back by early June. In the quietest week (early October) they are still on about 2.7% of checklists.
When do Great-tailed Grackles leave Utah?
Great-tailed Grackles never fully leave Utah: numbers fall back below half their usual rate by early June, but some are still reported in every week, about 2.7% of checklists at the low.
When is the best time to see a Great-tailed Grackle in Utah?
The Great-tailed Grackle is reported most often in late April, on about 7.9% of Utah checklists.
Where in Utah are Great-tailed Grackles seen most often?
By county, Box Elder County, Iron County, and Washington County have the highest peak reporting rates for the Great-tailed Grackle (counties with at least 200 checklists).