WhenToBird

Quiscalus quiscula · Icteridae

When Do Common Grackles Arrive in Wisconsin?

Adult Common Grackle
Photo: Derek Spencer, CC BY 4.0 via iNaturalist

Common Grackles reach Wisconsin in late February, are common by the second week of March, peak in the second week of May (41% of checklists), and most are gone by mid August.

When to look

First arrivalsFeb 22-28late February
Common byMar 8-14the second week of March
PeakMay 8-14the second week of May
Most gone byAug 15-21mid August

Best: the second week of May. First arrivals late February; most are gone by mid August. Peak: on about 41% of Wisconsin checklists.

  1. Jannot usually seen
  2. Febrare
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Sepuncommon
  10. Octuncommon
  11. Novrare
  12. Decnot usually seen

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

0%20%40%60%Jan 1-7: 0.2% of 27925 checklistsJan 8-14: 0.3% of 18337 checklistsJan 15-21: 0.2% of 17370 checklistsJan 22-31: 0.3% of 23777 checklistsFeb 1-7: 0.3% of 16656 checklistsFeb 8-14: 0.3% of 18286 checklistsFeb 15-21: 0.6% of 24739 checklistsFeb 22-28: 2.6% of 20113 checklistsMar 1-7: 11% of 24024 checklistsMar 8-14: 22% of 26722 checklistsMar 15-21: 27% of 27238 checklistsMar 22-31: 31% of 40171 checklistsApr 1-7: 35% of 34961 checklistsApr 8-14: 36% of 39128 checklistsApr 15-21: 37% of 38887 checklistsApr 22-30: 38% of 57231 checklistsMay 1-7: 41% of 55115 checklistsMay 8-14: 41% of 63098 checklistsMay 15-21: 41% of 49821 checklistsMay 22-31: 39% of 56796 checklistsJun 1-7: 37% of 33621 checklistsJun 8-14: 36% of 31282 checklistsJun 15-21: 34% of 30186 checklistsJun 22-30: 33% of 35128 checklistsJul 1-7: 31% of 27088 checklistsJul 8-14: 29% of 23293 checklistsJul 15-21: 26% of 20933 checklistsJul 22-31: 24% of 27595 checklistsAug 1-7: 23% of 19147 checklistsAug 8-14: 19% of 18286 checklistsAug 15-21: 18% of 19195 checklistsAug 22-31: 15% of 28229 checklistsSep 1-7: 11% of 22408 checklistsSep 8-14: 9.8% of 20857 checklistsSep 15-21: 9.4% of 20707 checklistsSep 22-30: 8.6% of 26469 checklistsOct 1-7: 9.6% of 21069 checklistsOct 8-14: 10% of 21011 checklistsOct 15-21: 9.5% of 20006 checklistsOct 22-31: 7.8% of 26362 checklistsNov 1-7: 4.6% of 18928 checklistsNov 8-14: 1.9% of 17052 checklistsNov 15-21: 1.0% of 16291 checklistsNov 22-30: 0.6% of 20564 checklistsDec 1-7: 0.4% of 15354 checklistsDec 8-14: 0.5% of 16294 checklistsDec 15-21: 0.3% of 21430 checklistsDec 22-31: 0.3% of 26314 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 Wisconsin 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 Wisconsin

Best counties

Share of checklists at the peak
  1. Winnebago CountyBest mid May · 812 checklists that week, 26,460 in all64%
  2. La Crosse CountyBest early May · 752 checklists that week, 15,788 in all64%
  3. Clark CountyBest the second week of April · 42 checklists that week, 2,369 in all60%
  4. Milwaukee CountyBest the second week of June · 1621 checklists that week, 114,667 in all60%
  5. Racine CountyBest mid May · 603 checklists that week, 18,400 in all58%
  6. Kenosha CountyBest early June · 242 checklists that week, 11,654 in all56%

Best spots

Share of checklists at the peak
  1. Great River State TrailLa Crosse County, best the second week of May · 20 checklists that week, 146 in all96%
  2. La Crosse River MarshLa Crosse County, best mid April · 36 checklists that week, 1,097 in all95%
  3. North Island TrailOutagamie County, best late April · 21 checklists that week, 461 in all94%
  4. Washington ParkMilwaukee County, best early April · 40 checklists that week, 984 in all94%
  5. Samuel Meyers ParkRacine County, best late May · 37 checklists that week, 1,144 in all94%
  6. Chiwaukee Prairie-Carol Beach Natural AreaKenosha County, best early May · 46 checklists that week, 504 in all93%

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

Best time of day

In Wisconsin, the Common Grackle is most often listed on checklists started between 5 and 7 am (36% of those checklists).

0%10%20%30%40%12 am: too few checklists (993) to judge1 am: too few checklists (844) to judge2 am: too few checklists (839) to judge3 am: too few checklists (1488) to judge4 am: too few checklists (5344) to judge5 am: 38% of 27016 checklists6 am: 35% of 83973 checklists7 am: 26% of 160717 checklists8 am: 24% of 160531 checklists9 am: 21% of 136968 checklists10 am: 19% of 119110 checklists11 am: 17% of 99116 checklists12 pm: 16% of 85078 checklists1 pm: 16% of 80688 checklists2 pm: 16% of 79140 checklists3 pm: 17% of 78599 checklists4 pm: 21% of 69767 checklists5 pm: 26% of 53229 checklists6 pm: 29% of 38769 checklists7 pm: too few checklists (24396) to judge8 pm: too few checklists (10155) to judge9 pm: too few checklists (4990) to judge10 pm: too few checklists (2463) to judge11 pm: too few checklists (1281) 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
January0.2%0.3%0.2%0.3%
February0.3%0.3%0.6%2.6%
March11%22%27%31%
April35%36%37%38%
May41%41%41%39%
June37%36%34%33%
July31%29%26%24%
August23%19%18%15%
September11%9.8%9.4%8.6%
October9.6%10%9.5%7.8%
November4.6%1.9%1.0%0.6%
December0.4%0.5%0.3%0.3%

Neighboring states

  • Illinois: arrives the second week of February, 2 weeks earlier than Wisconsin
  • Iowa: arrives late February, in the same week than Wisconsin
  • Michigan: arrives mid February, 1 week earlier than Wisconsin
  • Minnesota: arrives early March, 1 week later than Wisconsin

Common questions

When do Common Grackles arrive in Wisconsin?
Common Grackles reach Wisconsin in late February, are common by the second week of March, peak in the second week of May (41% of checklists), and most are gone by mid August.
When do Common Grackles leave Wisconsin?
Most Common Grackles have left Wisconsin by mid August, when reports fall below half their usual rate. Stragglers are still reported until early November.
When is the best time to see a Common Grackle in Wisconsin?
The Common Grackle is reported most often in the second week of May, on about 41% of Wisconsin checklists.
Where in Wisconsin are Common Grackles seen most often?
By county, Winnebago County, La Crosse County, and Clark County have the highest peak reporting rates for the Common Grackle (counties with at least 200 checklists).