WhenToBird

Certhia americana · Certhiidae

When Do Brown Creepers Arrive in Illinois?

Adult Brown Creeper
Photo: Melanie Gaddy, CC0 1.0 via iNaturalist

Brown Creepers reach Illinois in mid September, are common by late September, peak in the second week of April (14% of checklists), and most are gone by early May.

When to look

First arrivalsSep 15-21mid September
Common bySep 22-30late September
PeakApr 8-14the second week of April
Most gone byMay 1-7early May

Best: the second week of April. First arrivals mid September; most are gone by early May. Peak: on about 14% of Illinois checklists.

  1. Jancommon
  2. Febuncommon
  3. Marcommon
  4. Aprpeak season
  5. Mayuncommon
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepuncommon
  10. Octpeak season
  11. Novcommon
  12. Deccommon

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

0%5%10%15%Jan 1-7: 5.2% of 29700 checklistsJan 8-14: 4.4% of 20189 checklistsJan 15-21: 4.0% of 19784 checklistsJan 22-31: 4.7% of 26641 checklistsFeb 1-7: 4.2% of 20478 checklistsFeb 8-14: 3.9% of 21967 checklistsFeb 15-21: 3.2% of 28735 checklistsFeb 22-28: 3.7% of 24223 checklistsMar 1-7: 3.4% of 26775 checklistsMar 8-14: 3.4% of 27579 checklistsMar 15-21: 4.1% of 27193 checklistsMar 22-31: 8.1% of 42278 checklistsApr 1-7: 14% of 34579 checklistsApr 8-14: 15% of 38290 checklistsApr 15-21: 12% of 39261 checklistsApr 22-30: 6.1% of 59584 checklistsMay 1-7: 2.0% of 60485 checklistsMay 8-14: 0.8% of 59647 checklistsMay 15-21: 0.3% of 43173 checklistsMay 22-31: 0.1% of 47913 checklistsJun 1-7: 0.1% of 31151 checklistsJun 8-14: 0.1% of 27692 checklistsJun 15-21: 0.1% of 23983 checklistsJun 22-30: 0.1% of 28448 checklistsJul 1-7: 0.1% of 21273 checklistsJul 8-14: 0.1% of 19284 checklistsJul 15-21: 0.1% of 17712 checklistsJul 22-31: 0.1% of 24500 checklistsAug 1-7: 0.1% of 18498 checklistsAug 8-14: 0.1% of 19331 checklistsAug 15-21: 0.1% of 19983 checklistsAug 22-31: 0.1% of 31892 checklistsSep 1-7: 0.1% of 26396 checklistsSep 8-14: 0.2% of 25011 checklistsSep 15-21: 0.7% of 23597 checklistsSep 22-30: 5.6% of 30638 checklistsOct 1-7: 9.5% of 23949 checklistsOct 8-14: 12% of 24412 checklistsOct 15-21: 11% of 22359 checklistsOct 22-31: 9.1% of 29794 checklistsNov 1-7: 7.2% of 21877 checklistsNov 8-14: 5.9% of 19742 checklistsNov 15-21: 5.6% of 18989 checklistsNov 22-30: 5.5% of 23905 checklistsDec 1-7: 5.3% of 16935 checklistsDec 8-14: 5.7% of 16687 checklistsDec 15-21: 7.4% of 20931 checklistsDec 22-31: 6.7% of 29011 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 Illinois 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 Illinois

Best counties

Share of checklists at the peak
  1. Stark CountyBest late January · 13 checklists that week, 574 in all44%
  2. Wabash CountyBest the second week of December · 15 checklists that week, 602 in all40%
  3. Piatt CountyBest late December · 62 checklists that week, 4,640 in all31%
  4. Putnam CountyBest the second week of January · 18 checklists that week, 3,333 in all26%
  5. Mercer CountyBest the second week of February · 15 checklists that week, 949 in all25%
  6. Hardin CountyBest mid December · 10 checklists that week, 626 in all24%

Best spots

Share of checklists at the peak
  1. Navy Pier ParkCook County, best the second week of October · 23 checklists that week, 801 in all76%
  2. Eggers WoodsCook County, best the second week of April · 46 checklists that week, 1,158 in all64%
  3. Dam Number 4 South WoodsCook County, best the second week of April · 30 checklists that week, 492 in all63%
  4. Skokie Lagoons (Crow Island)Cook County, best the second week of April · 116 checklists that week, 3,351 in all62%
  5. Jackson (Andrew) (Jackson Park Highlands)Cook County, best the second week of April · 21 checklists that week, 358 in all62%

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

Best time of day

In Illinois, the Brown Creeper is most often listed on checklists started between 7 and 9 am (5.3% of those checklists).

0%2%4%6%12 am: too few checklists (484) to judge1 am: too few checklists (631) to judge2 am: too few checklists (485) to judge3 am: too few checklists (610) to judge4 am: too few checklists (2321) to judge5 am: too few checklists (23536) to judge6 am: 3.8% of 95511 checklists7 am: 5.3% of 164584 checklists8 am: 5.2% of 163654 checklists9 am: 4.8% of 141804 checklists10 am: 4.5% of 122882 checklists11 am: 4.4% of 100640 checklists12 pm: 4.6% of 89894 checklists1 pm: 4.5% of 82729 checklists2 pm: 4.4% of 79801 checklists3 pm: 4.2% of 82169 checklists4 pm: 3.9% of 75124 checklists5 pm: 3.1% of 57708 checklists6 pm: 1.4% of 41843 checklists7 pm: too few checklists (20943) to judge8 pm: too few checklists (6131) to judge9 pm: too few checklists (1677) to judge10 pm: too few checklists (843) to judge11 pm: too few checklists (448) 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
January5.2%4.4%4.0%4.7%
February4.2%3.9%3.2%3.7%
March3.4%3.4%4.1%8.1%
April14%15%12%6.1%
May2.0%0.8%0.3%0.1%
June0.1%0.1%0.1%0.1%
July0.1%0.1%0.1%0.1%
August0.1%0.1%0.1%0.1%
September0.1%0.2%0.7%5.6%
October9.5%12%11%9.1%
November7.2%5.9%5.6%5.5%
December5.3%5.7%7.4%6.7%

Neighboring states

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

Common questions

When do Brown Creepers arrive in Illinois?
Brown Creepers reach Illinois in mid September, are common by late September, peak in the second week of April (14% of checklists), and most are gone by early May.
When do Brown Creepers leave Illinois?
Most Brown Creepers have left Illinois by early May, when reports fall below half their usual rate. Stragglers are still reported until the second week of May.
When is the best time to see a Brown Creeper in Illinois?
The Brown Creeper is reported most often in the second week of April, on about 14% of Illinois checklists.
Where in Illinois are Brown Creepers seen most often?
By county, Stark County, Wabash County, and Piatt County have the highest peak reporting rates for the Brown Creeper (counties with at least 200 checklists).