WhenToBird

Dolichonyx oryzivorus · Icteridae

When Do Bobolinks Arrive in Wisconsin?

Adult male Bobolink
Photo: Derek Spencer, CC BY 4.0 via iNaturalist

Bobolinks mostly pass through Wisconsin: the first show up in early May, they are common by the second week of May, peak in the second week of June (7.1% of checklists), and most are gone by the second week of July.

When to look

First arrivalsMay 1-7early May
Common byMay 8-14the second week of May
PeakJun 8-14the second week of June
Most gone byJul 8-14the second week of July

Best: the second week of June. First arrivals early May; most are gone by the second week of July. Peak: on about 7.1% of Wisconsin checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprrare
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Auguncommon
  9. Seprare
  10. Octrare
  11. Novnot usually seen
  12. Decnot usually seen

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

0%2%4%6%8%Jan 1-7: 0% of 27925 checklistsJan 8-14: 0% of 18337 checklistsJan 15-21: 0% of 17370 checklistsJan 22-31: 0% of 23777 checklistsFeb 1-7: 0% of 16656 checklistsFeb 8-14: 0% of 18286 checklistsFeb 15-21: 0% of 24739 checklistsFeb 22-28: 0% of 20113 checklistsMar 1-7: 0% of 24024 checklistsMar 8-14: 0% of 26722 checklistsMar 15-21: 0% of 27238 checklistsMar 22-31: 0% of 40171 checklistsApr 1-7: 0% of 34961 checklistsApr 8-14: 0.1% of 39128 checklistsApr 15-21: 0.1% of 38887 checklistsApr 22-30: 0.1% of 57231 checklistsMay 1-7: 1.4% of 55115 checklistsMay 8-14: 3.5% of 63098 checklistsMay 15-21: 4.6% of 49821 checklistsMay 22-31: 5.7% of 56796 checklistsJun 1-7: 7.5% of 33621 checklistsJun 8-14: 7.3% of 31282 checklistsJun 15-21: 6.4% of 30186 checklistsJun 22-30: 5.4% of 35128 checklistsJul 1-7: 4.0% of 27088 checklistsJul 8-14: 2.5% of 23293 checklistsJul 15-21: 1.8% of 20933 checklistsJul 22-31: 1.2% of 27595 checklistsAug 1-7: 1.1% of 19147 checklistsAug 8-14: 1.0% of 18286 checklistsAug 15-21: 1.0% of 19195 checklistsAug 22-31: 1.0% of 28229 checklistsSep 1-7: 1.0% of 22408 checklistsSep 8-14: 0.7% of 20857 checklistsSep 15-21: 1.0% of 20707 checklistsSep 22-30: 0.7% of 26469 checklistsOct 1-7: 0.4% of 21069 checklistsOct 8-14: 0.1% of 21011 checklistsOct 15-21: 0.1% of 20006 checklistsOct 22-31: 0.1% of 26362 checklistsNov 1-7: 0% of 18928 checklistsNov 8-14: 0% of 17052 checklistsNov 15-21: 0% of 16291 checklistsNov 22-30: 0% of 20564 checklistsDec 1-7: 0% of 15354 checklistsDec 8-14: 0% of 16294 checklistsDec 15-21: 0% of 21430 checklistsDec 22-31: 0% 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. Portage CountyBest the second week of June · 742 checklists that week, 32,201 in all24%
  2. Iowa CountyBest the second week of June · 444 checklists that week, 18,836 in all21%
  3. Dodge CountyBest late May · 1620 checklists that week, 34,980 in all20%
  4. St. Croix CountyBest the second week of June · 328 checklists that week, 12,346 in all19%
  5. Clark CountyBest late May · 217 checklists that week, 2,369 in all18%
  6. Calumet CountyBest early June · 239 checklists that week, 12,359 in all16%

Best spots

Share of checklists at the peak
  1. Buena Vista Wildlife AreaPortage County, best the second week of June · 24 checklists that week, 519 in all94%
  2. Sheboygan Marsh Wildlife AreaSheboygan County, best the second week of May · 21 checklists that week, 184 in all92%
  3. Horicon National Wildlife Refuge (southeast 5)Dodge County, best mid May · 23 checklists that week, 245 in all92%
  4. Thomson Memorial PrairieDane County, best mid May · 81 checklists that week, 758 in all90%

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

Best time of day

In Wisconsin, the Bobolink is most often listed on checklists started between 5 and 7 am (3.4% of those checklists).

0%2%4%6%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: 4.3% of 27016 checklists6 am: 3.1% of 83973 checklists7 am: 1.9% of 160717 checklists8 am: 1.7% of 160531 checklists9 am: 1.7% of 136968 checklists10 am: 1.5% of 119110 checklists11 am: 1.3% of 99116 checklists12 pm: 1.2% of 85078 checklists1 pm: 1.0% of 80688 checklists2 pm: 1.0% of 79140 checklists3 pm: 1.0% of 78599 checklists4 pm: 1.0% of 69767 checklists5 pm: 1.3% of 53229 checklists6 pm: 1.6% 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%0%0%0%
February0%0%0%0%
March0%0%0%0%
April0%0.1%0.1%0.1%
May1.4%3.5%4.6%5.7%
June7.5%7.3%6.4%5.4%
July4.0%2.5%1.8%1.2%
August1.1%1.0%1.0%1.0%
September1.0%0.7%1.0%0.7%
October0.4%0.1%0.1%0.1%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • Illinois: arrives early May, in the same week than Wisconsin
  • Iowa: arrives early May, in the same week than Wisconsin
  • Michigan: arrives early May, in the same week than Wisconsin
  • Minnesota: arrives early May, in the same week than Wisconsin

Common questions

When do Bobolinks arrive in Wisconsin?
Bobolinks mostly pass through Wisconsin: the first show up in early May, they are common by the second week of May, peak in the second week of June (7.1% of checklists), and most are gone by the second week of July.
When do Bobolinks leave Wisconsin?
Most Bobolinks have left Wisconsin by the second week of July, when reports fall below half their usual rate. Stragglers are still reported until late August.
When is the best time to see a Bobolink in Wisconsin?
The Bobolink is reported most often in the second week of June, on about 7.1% of Wisconsin checklists.
Where in Wisconsin are Bobolinks seen most often?
By county, Portage County, Iowa County, and Dodge County have the highest peak reporting rates for the Bobolink (counties with at least 200 checklists).