WhenToBird

Toxostoma rufum · Mimidae

When Do Brown Thrashers Arrive in Michigan?

Adult Brown Thrasher
Photo: northerly, CC BY 4.0 via iNaturalist

Brown Thrashers reach Michigan in early April, are common by the second week of April, peak in the second week of May (10% of checklists), and most are gone by late September.

When to look

First arrivalsApr 1-7early April
Common byApr 8-14the second week of April
PeakMay 8-14the second week of May
Most gone bySep 22-30late September

Best: the second week of May. First arrivals early April; most are gone by late September. Peak: on about 10% of Michigan checklists.

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

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

0%5%10%15%Jan 1-7: 0.1% of 38160 checklistsJan 8-14: 0.1% of 24696 checklistsJan 15-21: 0.1% of 23771 checklistsJan 22-31: 0.1% of 31347 checklistsFeb 1-7: 0.1% of 23225 checklistsFeb 8-14: 0.1% of 27398 checklistsFeb 15-21: 0.1% of 36606 checklistsFeb 22-28: 0.1% of 27127 checklistsMar 1-7: 0.1% of 29700 checklistsMar 8-14: 0.1% of 31587 checklistsMar 15-21: 0.1% of 32118 checklistsMar 22-31: 0.1% of 47777 checklistsApr 1-7: 0.7% of 38557 checklistsApr 8-14: 2.9% of 42207 checklistsApr 15-21: 6.1% of 42759 checklistsApr 22-30: 9.0% of 64458 checklistsMay 1-7: 9.9% of 60998 checklistsMay 8-14: 9.6% of 72091 checklistsMay 15-21: 11% of 59058 checklistsMay 22-31: 9.4% of 64724 checklistsJun 1-7: 8.5% of 35990 checklistsJun 8-14: 8.6% of 32595 checklistsJun 15-21: 8.0% of 30017 checklistsJun 22-30: 6.8% of 33988 checklistsJul 1-7: 5.7% of 28708 checklistsJul 8-14: 4.6% of 25175 checklistsJul 15-21: 3.4% of 24084 checklistsJul 22-31: 2.7% of 33522 checklistsAug 1-7: 2.2% of 25098 checklistsAug 8-14: 1.9% of 24353 checklistsAug 15-21: 1.8% of 25059 checklistsAug 22-31: 2.0% of 37489 checklistsSep 1-7: 2.4% of 28410 checklistsSep 8-14: 3.2% of 27887 checklistsSep 15-21: 4.0% of 26614 checklistsSep 22-30: 3.1% of 32557 checklistsOct 1-7: 1.4% of 25844 checklistsOct 8-14: 0.4% of 27741 checklistsOct 15-21: 0.1% of 24693 checklistsOct 22-31: 0.1% of 32460 checklistsNov 1-7: 0.1% of 23660 checklistsNov 8-14: 0.1% of 21542 checklistsNov 15-21: 0.1% of 19922 checklistsNov 22-30: 0.1% of 25069 checklistsDec 1-7: 0.1% of 18272 checklistsDec 8-14: 0.1% of 18961 checklistsDec 15-21: 0.1% of 24171 checklistsDec 22-31: 0.1% of 30908 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 Michigan 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.

Embed this map on your site

Where in Michigan

Best counties

Share of checklists at the peak
  1. Iosco CountyBest mid May · 4977 checklists that week, 31,409 in all39%
  2. Crawford CountyBest mid June · 1178 checklists that week, 16,949 in all33%
  3. Otsego CountyBest the second week of May · 204 checklists that week, 7,286 in all31%
  4. Ionia CountyBest early May · 229 checklists that week, 5,509 in all26%
  5. Osceola CountyBest mid June · 127 checklists that week, 5,623 in all26%
  6. Benzie CountyBest early May · 571 checklists that week, 14,114 in all25%

Best spots

Share of checklists at the peak
  1. Kirtland Warbler Unit Clear LakeCrawford County, best the second week of June · 72 checklists that week, 438 in all86%
  2. Tawas Point State ParkIosco County, best mid June · 73 checklists that week, 8,006 in all73%
  3. Rolling Hills County ParkWashtenaw County, best early June · 42 checklists that week, 693 in all67%
  4. Kirtland Warbler Unit ManisteeCrawford County, best mid May · 27 checklists that week, 181 in all67%
  5. Flushing Township ParkGenesee County, best mid May · 42 checklists that week, 1,247 in all66%

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

Best time of day

In Michigan, the Brown Thrasher is most often listed on checklists started between 6 and 8 am (7.9% of those checklists).

0%5%10%15%12 am: too few checklists (712) to judge1 am: too few checklists (592) to judge2 am: too few checklists (532) to judge3 am: too few checklists (516) to judge4 am: too few checklists (1592) to judge5 am: too few checklists (6849) to judge6 am: 10% of 39298 checklists7 am: 7.1% of 120344 checklists8 am: 5.3% of 180109 checklists9 am: 4.2% of 171966 checklists10 am: 3.4% of 156332 checklists11 am: 2.7% of 134964 checklists12 pm: 2.4% of 120967 checklists1 pm: 2.1% of 113852 checklists2 pm: 1.9% of 110773 checklists3 pm: 1.9% of 105530 checklists4 pm: 2.1% of 100958 checklists5 pm: 2.4% of 80085 checklists6 pm: 3.1% of 62883 checklists7 pm: 3.4% of 44912 checklists8 pm: too few checklists (21062) to judge9 pm: too few checklists (5920) to judge10 pm: too few checklists (1629) to judge11 pm: too few checklists (775) 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
January0.1%0.1%0.1%0.1%
February0.1%0.1%0.1%0.1%
March0.1%0.1%0.1%0.1%
April0.7%2.9%6.1%9.0%
May9.9%9.6%11%9.4%
June8.5%8.6%8.0%6.8%
July5.7%4.6%3.4%2.7%
August2.2%1.9%1.8%2.0%
September2.4%3.2%4.0%3.1%
October1.4%0.4%0.1%0.1%
November0.1%0.1%0.1%0.1%
December0.1%0.1%0.1%0.1%

Neighboring states

  • Ohio: arrives mid March, 2 weeks earlier than Michigan
  • Indiana: arrives the second week of March, 3 weeks earlier than Michigan
  • Illinois: arrives mid March, 2 weeks earlier than Michigan
  • Wisconsin: arrives early April, in the same week than Michigan

Common questions

When do Brown Thrashers arrive in Michigan?
Brown Thrashers reach Michigan in early April, are common by the second week of April, peak in the second week of May (10% of checklists), and most are gone by late September.
When do Brown Thrashers leave Michigan?
Most Brown Thrashers have left Michigan by late September, when reports fall below half their usual rate. Stragglers are still reported until early October.
When is the best time to see a Brown Thrasher in Michigan?
The Brown Thrasher is reported most often in the second week of May, on about 10% of Michigan checklists.
Where in Michigan are Brown Thrashers seen most often?
By county, Iosco County, Crawford County, and Otsego County have the highest peak reporting rates for the Brown Thrasher (counties with at least 200 checklists).