WhenToBird

Passerella iliaca · Passerellidae

When Do Fox Sparrows Arrive in Wisconsin?

Adult Fox Sparrow
Photo: Kevin Krebs, CC BY 4.0 via iNaturalist

Fox Sparrows arrive in Wisconsin in early March, peak in early April (10% of checklists), and most are gone by late April.

When to look

First arrivalsMar 1-7early March
Common byMar 1-7early March
PeakApr 1-7early April
Most gone byApr 22-30late April

Best: early April. First arrivals early March; most are gone by late April. Peak: on about 10% of Wisconsin checklists.

  1. Janrare
  2. Febrare
  3. Marpeak season
  4. Aprpeak season
  5. Mayrare
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Seprare
  10. Octpeak season
  11. Novcommon
  12. Decrare

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

0%5%10%15%Jan 1-7: 1.1% of 27925 checklistsJan 8-14: 1.2% of 18337 checklistsJan 15-21: 1.3% of 17370 checklistsJan 22-31: 1.1% of 23777 checklistsFeb 1-7: 0.7% of 16656 checklistsFeb 8-14: 0.7% of 18286 checklistsFeb 15-21: 0.6% of 24739 checklistsFeb 22-28: 0.6% of 20113 checklistsMar 1-7: 0.8% of 24024 checklistsMar 8-14: 2.1% of 26722 checklistsMar 15-21: 3.9% of 27238 checklistsMar 22-31: 8.2% of 40171 checklistsApr 1-7: 13% of 34961 checklistsApr 8-14: 10% of 39128 checklistsApr 15-21: 7.7% of 38887 checklistsApr 22-30: 2.2% of 57231 checklistsMay 1-7: 0.2% of 55115 checklistsMay 8-14: 0.1% of 63098 checklistsMay 15-21: 0.1% of 49821 checklistsMay 22-31: 0.1% of 56796 checklistsJun 1-7: 0% of 33621 checklistsJun 8-14: 0% of 31282 checklistsJun 15-21: 0% of 30186 checklistsJun 22-30: 0% of 35128 checklistsJul 1-7: 0% of 27088 checklistsJul 8-14: 0% of 23293 checklistsJul 15-21: 0% of 20933 checklistsJul 22-31: 0% of 27595 checklistsAug 1-7: 0% of 19147 checklistsAug 8-14: 0% of 18286 checklistsAug 15-21: 0% of 19195 checklistsAug 22-31: 0% of 28229 checklistsSep 1-7: 0% of 22408 checklistsSep 8-14: 0.1% of 20857 checklistsSep 15-21: 0.1% of 20707 checklistsSep 22-30: 0.6% of 26469 checklistsOct 1-7: 2.4% of 21069 checklistsOct 8-14: 5.8% of 21011 checklistsOct 15-21: 8.5% of 20006 checklistsOct 22-31: 9.2% of 26362 checklistsNov 1-7: 7.6% of 18928 checklistsNov 8-14: 5.4% of 17052 checklistsNov 15-21: 3.0% of 16291 checklistsNov 22-30: 1.4% of 20564 checklistsDec 1-7: 0.9% of 15354 checklistsDec 8-14: 0.9% of 16294 checklistsDec 15-21: 0.9% of 21430 checklistsDec 22-31: 0.8% 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. Washburn CountyBest the second week of April · 131 checklists that week, 7,099 in all26%
  2. Dunn CountyBest mid October · 111 checklists that week, 8,247 in all26%
  3. Iron CountyBest mid April · 194 checklists that week, 5,981 in all24%
  4. Vernon CountyBest early November · 123 checklists that week, 13,255 in all24%
  5. Lafayette CountyBest early November · 16 checklists that week, 1,911 in all21%
  6. Florence CountyBest the second week of April · 192 checklists that week, 10,179 in all20%

Best spots

Share of checklists at the peak
  1. Uw Arboretum (northwest)Dane County, best early January · 169 checklists that week, 1,523 in all64%
  2. Estabrook ParkMilwaukee County, best late March · 90 checklists that week, 3,253 in all60%
  3. Mosquito HillOutagamie County, best the second week of April · 26 checklists that week, 395 in all58%
  4. Hoffman Hills Recreation AreaDunn County, best early April · 23 checklists that week, 615 in all56%
  5. Big Donahue LakeVilas County, best mid April · 22 checklists that week, 214 in all50%
  6. Lakeshore PreserveDane County, best late March · 84 checklists that week, 3,146 in all48%

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

Best time of day

In Wisconsin, the Fox Sparrow is most often listed on checklists started between 7 and 9 am (3.1% of those checklists).

0%1%2%3%4%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: 0.7% of 27016 checklists6 am: 2.5% of 83973 checklists7 am: 3.3% of 160717 checklists8 am: 2.9% of 160531 checklists9 am: 2.4% of 136968 checklists10 am: 2.2% of 119110 checklists11 am: 2.0% of 99116 checklists12 pm: 1.8% of 85078 checklists1 pm: 1.9% of 80688 checklists2 pm: 1.8% of 79140 checklists3 pm: 2.0% of 78599 checklists4 pm: 2.0% of 69767 checklists5 pm: 2.1% of 53229 checklists6 pm: 1.4% 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
January1.1%1.2%1.3%1.1%
February0.7%0.7%0.6%0.6%
March0.8%2.1%3.9%8.2%
April13%10%7.7%2.2%
May0.2%0.1%0.1%0.1%
June0%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0%0.1%0.1%0.6%
October2.4%5.8%8.5%9.2%
November7.6%5.4%3.0%1.4%
December0.9%0.9%0.9%0.8%

Neighboring states

  • Illinois: arrives early October, 20 weeks earlier than Wisconsin
  • Iowa: arrives early October, 20 weeks earlier than Wisconsin
  • Michigan: arrives the second week of March, 1 week later than Wisconsin
  • Minnesota: arrives the second week of March, 1 week later than Wisconsin

Common questions

When do Fox Sparrows arrive in Wisconsin?
Fox Sparrows arrive in Wisconsin in early March, peak in early April (10% of checklists), and most are gone by late April.
When do Fox Sparrows leave Wisconsin?
Most Fox Sparrows have left Wisconsin by late April, when reports fall below half their usual rate.
When is the best time to see a Fox Sparrow in Wisconsin?
The Fox Sparrow is reported most often in early April, on about 10% of Wisconsin checklists.
Where in Wisconsin are Fox Sparrows seen most often?
By county, Washburn County, Dunn County, and Iron County have the highest peak reporting rates for the Fox Sparrow (counties with at least 200 checklists).