WhenToBird

Cistothorus palustris · Troglodytidae

When Do Marsh Wrens Arrive in Utah?

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

Marsh Wrens are in Utah all year, but most are here in fall: numbers build from mid August, peak in the second week of September (6.7% of checklists), and fall back by early November. In the quietest week (the second week of February) they are still on about 2.1% of checklists.

When to look

Numbers buildAug 15-21mid August
PeakSep 8-14the second week of September
Fall back byNov 1-7early November
FewestFeb 8-14the second week of February

Best: the second week of September. Here all year; numbers build from mid August and fall back by early November. Peak: on about 6.7% of Utah checklists.

  1. Januncommon
  2. Febuncommon
  3. Marcommon
  4. Aprcommon
  5. Maycommon
  6. Jununcommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novcommon
  12. Deccommon

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

0%2%4%6%8%Jan 1-7: 2.2% of 10857 checklistsJan 8-14: 2.3% of 8333 checklistsJan 15-21: 2.3% of 8360 checklistsJan 22-31: 2.4% of 10516 checklistsFeb 1-7: 2.0% of 7416 checklistsFeb 8-14: 2.3% of 8082 checklistsFeb 15-21: 2.1% of 9643 checklistsFeb 22-28: 2.9% of 7960 checklistsMar 1-7: 3.1% of 7998 checklistsMar 8-14: 3.2% of 8581 checklistsMar 15-21: 3.9% of 8637 checklistsMar 22-31: 4.0% of 13006 checklistsApr 1-7: 4.6% of 10562 checklistsApr 8-14: 4.1% of 11694 checklistsApr 15-21: 4.0% of 11382 checklistsApr 22-30: 4.2% of 16626 checklistsMay 1-7: 3.9% of 13523 checklistsMay 8-14: 3.4% of 14714 checklistsMay 15-21: 3.7% of 13711 checklistsMay 22-31: 2.8% of 16546 checklistsJun 1-7: 2.3% of 10284 checklistsJun 8-14: 2.1% of 9530 checklistsJun 15-21: 2.2% of 8854 checklistsJun 22-30: 2.5% of 10566 checklistsJul 1-7: 2.6% of 7987 checklistsJul 8-14: 2.1% of 7471 checklistsJul 15-21: 2.3% of 7240 checklistsJul 22-31: 2.9% of 9329 checklistsAug 1-7: 3.5% of 6521 checklistsAug 8-14: 4.1% of 6423 checklistsAug 15-21: 4.6% of 6208 checklistsAug 22-31: 5.9% of 9089 checklistsSep 1-7: 7.6% of 7081 checklistsSep 8-14: 6.4% of 7306 checklistsSep 15-21: 6.1% of 7208 checklistsSep 22-30: 5.1% of 8876 checklistsOct 1-7: 5.9% of 7265 checklistsOct 8-14: 4.9% of 7226 checklistsOct 15-21: 4.6% of 7007 checklistsOct 22-31: 4.8% of 8443 checklistsNov 1-7: 4.3% of 6711 checklistsNov 8-14: 4.2% of 6290 checklistsNov 15-21: 4.1% of 6169 checklistsNov 22-30: 4.1% of 8228 checklistsDec 1-7: 3.0% of 6011 checklistsDec 8-14: 3.0% of 6044 checklistsDec 15-21: 3.3% of 6721 checklistsDec 22-31: 2.9% of 9982 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 Utah 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 Utah

Best counties

Share of checklists at the peak
  1. Box Elder CountyBest the second week of August · 207 checklists that week, 9,867 in all20%
  2. Davis CountyBest late September · 992 checklists that week, 39,952 in all18%
  3. Utah CountyBest the second week of September · 995 checklists that week, 70,971 in all15%
  4. Cache CountyBest the second week of September · 281 checklists that week, 21,769 in all15%
  5. Uintah CountyBest mid April · 322 checklists that week, 9,143 in all14%
  6. Juab CountyBest mid May · 120 checklists that week, 2,572 in all11%

Best spots

Share of checklists at the peak
  1. Ogden Bay State Wildlife AreaWeber County, best mid April · 22 checklists that week, 498 in all70%
  2. Stromquist (Tnc)Davis County, best late June · 21 checklists that week, 882 in all55%
  3. Utah State Department of Wildlife Resources 165Davis County, best mid June · 106 checklists that week, 4,840 in all54%

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

Best time of day

In Utah, the Marsh Wren is most often listed on checklists started between 6 and 8 am (5.7% of those checklists).

0%2%4%6%8%12 am: too few checklists (242) to judge1 am: too few checklists (178) to judge2 am: too few checklists (169) to judge3 am: too few checklists (162) to judge4 am: too few checklists (284) to judge5 am: too few checklists (1984) to judge6 am: 6.1% of 11714 checklists7 am: 5.6% of 33209 checklists8 am: 4.3% of 46944 checklists9 am: 4.0% of 46290 checklists10 am: 3.5% of 43144 checklists11 am: 3.3% of 36893 checklists12 pm: 3.4% of 32758 checklists1 pm: 3.1% of 30142 checklists2 pm: 2.8% of 29414 checklists3 pm: 2.8% of 29491 checklists4 pm: 3.0% of 29154 checklists5 pm: 3.4% of 22256 checklists6 pm: 3.1% of 17383 checklists7 pm: 2.5% of 13099 checklists8 pm: too few checklists (6647) to judge9 pm: too few checklists (1753) to judge10 pm: too few checklists (599) to judge11 pm: too few checklists (307) 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
January2.2%2.3%2.3%2.4%
February2.0%2.3%2.1%2.9%
March3.1%3.2%3.9%4.0%
April4.6%4.1%4.0%4.2%
May3.9%3.4%3.7%2.8%
June2.3%2.1%2.2%2.5%
July2.6%2.1%2.3%2.9%
August3.5%4.1%4.6%5.9%
September7.6%6.4%6.1%5.1%
October5.9%4.9%4.6%4.8%
November4.3%4.2%4.1%4.1%
December3.0%3.0%3.3%2.9%

Neighboring states

  • Wyoming: arrives late March, 19 weeks earlier than Utah
  • Nevada: arrives mid September, 4 weeks later than Utah
  • Colorado: arrives late February, 23 weeks earlier than Utah
  • Idaho: arrives late February, 23 weeks earlier than Utah

Common questions

When do Marsh Wrens arrive in Utah?
Marsh Wrens are in Utah all year, but most are here in fall: numbers build from mid August, peak in the second week of September (6.7% of checklists), and fall back by early November. In the quietest week (the second week of February) they are still on about 2.1% of checklists.
When do Marsh Wrens leave Utah?
Marsh Wrens never fully leave Utah: numbers fall back below half their usual rate by early November, but some are still reported in every week, about 2.1% of checklists at the low.
When is the best time to see a Marsh Wren in Utah?
The Marsh Wren is reported most often in the second week of September, on about 6.7% of Utah checklists.
Where in Utah are Marsh Wrens seen most often?
By county, Box Elder County, Davis County, and Utah County have the highest peak reporting rates for the Marsh Wren (counties with at least 200 checklists).