WhenToBird

Cistothorus palustris · Troglodytidae

When Do Marsh Wrens Arrive in Idaho?

Adult Marsh Wren
Photo: Kathy Richardson, CC BY 4.0 via iNaturalist

Marsh Wrens reach Idaho in late February, are common by early March, peak in mid May (3.5% of checklists), and most are gone by late December.

When to look

First arrivalsFeb 22-28late February
Common byMar 1-7early March
PeakMay 15-21mid May
Most gone byDec 22-31late December

Best: mid May. First arrivals late February; most are gone by late December. Peak: on about 3.5% of Idaho checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Deccommon

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

0%1%2%3%4%Jan 1-7: 1.7% of 9357 checklistsJan 8-14: 1.5% of 6408 checklistsJan 15-21: 1.3% of 6358 checklistsJan 22-31: 1.8% of 8601 checklistsFeb 1-7: 1.4% of 5611 checklistsFeb 8-14: 1.2% of 6090 checklistsFeb 15-21: 1.0% of 7973 checklistsFeb 22-28: 1.5% of 5866 checklistsMar 1-7: 1.7% of 6144 checklistsMar 8-14: 2.4% of 6456 checklistsMar 15-21: 2.7% of 6786 checklistsMar 22-31: 3.2% of 9539 checklistsApr 1-7: 3.3% of 7202 checklistsApr 8-14: 3.2% of 7608 checklistsApr 15-21: 3.7% of 8069 checklistsApr 22-30: 3.0% of 10973 checklistsMay 1-7: 3.6% of 9481 checklistsMay 8-14: 3.3% of 11318 checklistsMay 15-21: 3.5% of 9141 checklistsMay 22-31: 3.7% of 13984 checklistsJun 1-7: 3.0% of 8897 checklistsJun 8-14: 2.9% of 8504 checklistsJun 15-21: 3.0% of 8078 checklistsJun 22-30: 3.1% of 9665 checklistsJul 1-7: 3.1% of 7144 checklistsJul 8-14: 2.6% of 6557 checklistsJul 15-21: 2.4% of 6430 checklistsJul 22-31: 1.8% of 8696 checklistsAug 1-7: 2.0% of 5896 checklistsAug 8-14: 1.5% of 5643 checklistsAug 15-21: 2.0% of 6151 checklistsAug 22-31: 2.0% of 7863 checklistsSep 1-7: 2.5% of 5769 checklistsSep 8-14: 2.3% of 5646 checklistsSep 15-21: 2.1% of 5460 checklistsSep 22-30: 2.4% of 6363 checklistsOct 1-7: 2.4% of 4980 checklistsOct 8-14: 2.1% of 5096 checklistsOct 15-21: 2.1% of 4878 checklistsOct 22-31: 2.1% of 6426 checklistsNov 1-7: 2.4% of 4822 checklistsNov 8-14: 2.5% of 4999 checklistsNov 15-21: 1.9% of 4601 checklistsNov 22-30: 2.1% of 6027 checklistsDec 1-7: 1.9% of 4180 checklistsDec 8-14: 1.4% of 4775 checklistsDec 15-21: 2.1% of 6522 checklistsDec 22-31: 1.7% of 7792 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 Idaho 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 Idaho

Best counties

Share of checklists at the peak
  1. Elmore CountyBest early December · 39 checklists that week, 6,239 in all34%
  2. Jefferson CountyBest late May · 542 checklists that week, 5,319 in all28%
  3. Bear Lake CountyBest late June · 81 checklists that week, 1,581 in all26%
  4. Camas CountyBest mid June · 71 checklists that week, 2,112 in all24%
  5. Gooding CountyBest the second week of December · 26 checklists that week, 3,207 in all23%
  6. Owyhee CountyBest late July · 80 checklists that week, 7,837 in all16%

Best spots

Share of checklists at the peak
  1. Silver CreekBlaine County, best mid May · 21 checklists that week, 418 in all89%
  2. Morley Nelson Snake River Birds of Prey National Conservation AreaElmore County, best late November · 27 checklists that week, 1,056 in all79%
  3. Market Lake Wildlife Management AreaJefferson County, best mid May · 35 checklists that week, 697 in all75%
  4. Roswell Marsh Wildlife Habitat AreaCanyon County, best the second week of April · 22 checklists that week, 504 in all69%
  5. Mud Lake Wildlife Management AreaJefferson County, best late May · 35 checklists that week, 222 in all58%

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

Best time of day

In Idaho, the Marsh Wren is most often listed on checklists started between 9 and 11 am (2.8% of those checklists).

0%1%2%3%12 am: too few checklists (180) to judge1 am: too few checklists (176) to judge2 am: too few checklists (169) to judge3 am: too few checklists (164) to judge4 am: too few checklists (450) to judge5 am: too few checklists (2270) to judge6 am: 2.5% of 9122 checklists7 am: 2.5% of 22204 checklists8 am: 2.4% of 38672 checklists9 am: 2.9% of 38930 checklists10 am: 2.7% of 37338 checklists11 am: 2.5% of 33508 checklists12 pm: 2.6% of 28544 checklists1 pm: 2.6% of 25774 checklists2 pm: 2.3% of 24296 checklists3 pm: 2.2% of 21784 checklists4 pm: 1.9% of 19051 checklists5 pm: 1.8% of 14150 checklists6 pm: 2.3% of 10014 checklists7 pm: 2.0% of 7495 checklists8 pm: too few checklists (4352) to judge9 pm: too few checklists (1449) to judge10 pm: too few checklists (525) to judge11 pm: too few checklists (208) 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
January1.7%1.5%1.3%1.8%
February1.4%1.2%1.0%1.5%
March1.7%2.4%2.7%3.2%
April3.3%3.2%3.7%3.0%
May3.6%3.3%3.5%3.7%
June3.0%2.9%3.0%3.1%
July3.1%2.6%2.4%1.8%
August2.0%1.5%2.0%2.0%
September2.5%2.3%2.1%2.4%
October2.4%2.1%2.1%2.1%
November2.4%2.5%1.9%2.1%
December1.9%1.4%2.1%1.7%

Neighboring states

  • Montana: arrives early April, 5 weeks later than Idaho
  • Utah: arrives mid August, 23 weeks later than Idaho
  • Oregon: year-round, peaks the second week of April
  • Washington: arrives mid March, 3 weeks later than Idaho

Common questions

When do Marsh Wrens arrive in Idaho?
Marsh Wrens reach Idaho in late February, are common by early March, peak in mid May (3.5% of checklists), and most are gone by late December.
When do Marsh Wrens leave Idaho?
Most Marsh Wrens have left Idaho by late December, when reports fall below half their usual rate. Stragglers are still reported until early February.
When is the best time to see a Marsh Wren in Idaho?
The Marsh Wren is reported most often in mid May, on about 3.5% of Idaho checklists.
Where in Idaho are Marsh Wrens seen most often?
By county, Elmore County, Jefferson County, and Bear Lake County have the highest peak reporting rates for the Marsh Wren (counties with at least 200 checklists).