WhenToBird

Poecile gambeli · Paridae

When Do Mountain Chickadees Arrive in Wyoming?

Adult Mountain Chickadee
Photo: Wendy McCrady, CC BY 4.0 via iNaturalist

Mountain Chickadees are in Wyoming all year, but most are here in fall: numbers build from the second week of July, peak in early September (21% of checklists), and fall back by early November. In the quietest week (mid April) they are still on about 8.1% of checklists.

When to look

Numbers buildJul 8-14the second week of July
PeakSep 1-7early September
Fall back byNov 1-7early November
FewestApr 15-21mid April

Best: early September. Here all year; numbers build from the second week of July and fall back by early November. Peak: on about 21% of Wyoming checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Aprcommon
  5. Maycommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novcommon
  12. Decpeak season

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

0%10%20%30%Jan 1-7: 15% of 2543 checklistsJan 8-14: 16% of 2114 checklistsJan 15-21: 16% of 1984 checklistsJan 22-31: 16% of 2605 checklistsFeb 1-7: 16% of 1940 checklistsFeb 8-14: 17% of 1954 checklistsFeb 15-21: 16% of 2575 checklistsFeb 22-28: 16% of 1932 checklistsMar 1-7: 13% of 2486 checklistsMar 8-14: 12% of 2535 checklistsMar 15-21: 12% of 2726 checklistsMar 22-31: 10% of 4349 checklistsApr 1-7: 9.5% of 3300 checklistsApr 8-14: 7.7% of 3500 checklistsApr 15-21: 8.4% of 3701 checklistsApr 22-30: 8.2% of 5887 checklistsMay 1-7: 9.7% of 5341 checklistsMay 8-14: 9.8% of 6910 checklistsMay 15-21: 9.8% of 6884 checklistsMay 22-31: 11% of 10652 checklistsJun 1-7: 11% of 6807 checklistsJun 8-14: 10% of 6714 checklistsJun 15-21: 12% of 6708 checklistsJun 22-30: 13% of 8160 checklistsJul 1-7: 14% of 5755 checklistsJul 8-14: 14% of 5379 checklistsJul 15-21: 17% of 5299 checklistsJul 22-31: 16% of 6830 checklistsAug 1-7: 16% of 4581 checklistsAug 8-14: 17% of 4625 checklistsAug 15-21: 18% of 4466 checklistsAug 22-31: 21% of 6562 checklistsSep 1-7: 20% of 4543 checklistsSep 8-14: 20% of 4652 checklistsSep 15-21: 19% of 4186 checklistsSep 22-30: 20% of 5301 checklistsOct 1-7: 19% of 3248 checklistsOct 8-14: 17% of 3010 checklistsOct 15-21: 17% of 2624 checklistsOct 22-31: 16% of 3170 checklistsNov 1-7: 13% of 2110 checklistsNov 8-14: 15% of 2153 checklistsNov 15-21: 15% of 1971 checklistsNov 22-30: 17% of 2136 checklistsDec 1-7: 14% of 1646 checklistsDec 8-14: 14% of 1609 checklistsDec 15-21: 16% of 1954 checklistsDec 22-31: 16% of 2392 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 Wyoming 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 Wyoming

Best counties

Share of checklists at the peak
  1. Albany CountyBest early February · 266 checklists that week, 21,857 in all51%
  2. Teton CountyBest the second week of January · 181 checklists that week, 34,686 in all36%
  3. Sublette CountyBest mid October · 81 checklists that week, 6,738 in all31%
  4. Uinta CountyBest mid December · 16 checklists that week, 1,881 in all28%
  5. Big Horn CountyBest early September · 65 checklists that week, 2,023 in all26%
  6. Carbon CountyBest the second week of September · 181 checklists that week, 6,429 in all25%

Best spots

Share of checklists at the peak
  1. Medicine Bow National ForestAlbany County, best mid January · 23 checklists that week, 359 in all100%
  2. State Lands 1111128453Albany County, best late February · 47 checklists that week, 1,128 in all75%
  3. La Prele ParkAlbany County, best late October · 30 checklists that week, 639 in all72%
  4. String LakeTeton County, best late September · 20 checklists that week, 294 in all71%
  5. LaBonte ParkAlbany County, best late September · 22 checklists that week, 1,107 in all68%

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

Best time of day

In Wyoming, the Mountain Chickadee is most often listed on checklists started between 7 and 9 am (18% of those checklists).

0%5%10%15%20%12 am: too few checklists (59) to judge1 am: too few checklists (76) to judge2 am: too few checklists (86) to judge3 am: too few checklists (79) to judge4 am: too few checklists (326) to judge5 am: too few checklists (2271) to judge6 am: 17% of 8808 checklists7 am: 18% of 18458 checklists8 am: 18% of 22143 checklists9 am: 16% of 21499 checklists10 am: 15% of 19425 checklists11 am: 15% of 16017 checklists12 pm: 14% of 13868 checklists1 pm: 12% of 12984 checklists2 pm: 11% of 12605 checklists3 pm: 11% of 11821 checklists4 pm: 11% of 10571 checklists5 pm: 9.5% of 8746 checklists6 pm: 9.0% of 6707 checklists7 pm: 7.7% of 4890 checklists8 pm: too few checklists (2323) to judge9 pm: too few checklists (554) to judge10 pm: too few checklists (134) to judge11 pm: too few checklists (59) 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
January15%16%16%16%
February16%17%16%16%
March13%12%12%10%
April9.5%7.7%8.4%8.2%
May9.7%9.8%9.8%11%
June11%10%12%13%
July14%14%17%16%
August16%17%18%21%
September20%20%19%20%
October19%17%17%16%
November13%15%15%17%
December14%14%16%16%

Neighboring states

  • Colorado: year-round, peaks early August
  • Utah: arrives mid June, 3 weeks earlier than Wyoming
  • Montana: year-round, peaks mid December
  • Idaho: arrives mid June, 3 weeks earlier than Wyoming

Common questions

When do Mountain Chickadees arrive in Wyoming?
Mountain Chickadees are in Wyoming all year, but most are here in fall: numbers build from the second week of July, peak in early September (21% of checklists), and fall back by early November. In the quietest week (mid April) they are still on about 8.1% of checklists.
When do Mountain Chickadees leave Wyoming?
Mountain Chickadees never fully leave Wyoming: numbers fall back below half their usual rate by early November, but some are still reported in every week, about 8.1% of checklists at the low.
When is the best time to see a Mountain Chickadee in Wyoming?
The Mountain Chickadee is reported most often in early September, on about 21% of Wyoming checklists.
Where in Wyoming are Mountain Chickadees seen most often?
By county, Albany County, Teton County, and Sublette County have the highest peak reporting rates for the Mountain Chickadee (counties with at least 200 checklists).