WhenToBird

Cinclus mexicanus · Cinclidae

When Do American Dippers Arrive in Colorado?

Adult American Dipper
Photo: Jared Shorma, CC BY 4.0 via iNaturalist

American Dippers are winter birds in Colorado: the first arrive in mid September, they are common by late September, peak in the second week of January (3.1% of checklists), and most are gone by late July.

When to look

First arrivalsSep 15-21mid September
Common bySep 22-30late September
PeakJan 8-14the second week of January
Most gone byJul 22-31late July

Best: the second week of January. First arrivals mid September; most are gone by late July. Peak: on about 3.1% of Colorado checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprcommon
  5. Mayuncommon
  6. Juncommon
  7. Julcommon
  8. Auguncommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Decpeak season

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

0%1%2%3%4%Jan 1-7: 3.4% of 32254 checklistsJan 8-14: 2.8% of 23278 checklistsJan 15-21: 2.9% of 22933 checklistsJan 22-31: 3.0% of 30856 checklistsFeb 1-7: 3.2% of 21464 checklistsFeb 8-14: 2.7% of 22910 checklistsFeb 15-21: 2.4% of 28739 checklistsFeb 22-28: 2.7% of 21833 checklistsMar 1-7: 2.4% of 23066 checklistsMar 8-14: 2.1% of 23783 checklistsMar 15-21: 1.9% of 24797 checklistsMar 22-31: 1.7% of 38439 checklistsApr 1-7: 1.6% of 31676 checklistsApr 8-14: 1.4% of 35092 checklistsApr 15-21: 1.0% of 36778 checklistsApr 22-30: 1.0% of 50885 checklistsMay 1-7: 0.8% of 44186 checklistsMay 8-14: 1.0% of 49011 checklistsMay 15-21: 1.1% of 40784 checklistsMay 22-31: 1.2% of 53073 checklistsJun 1-7: 1.1% of 32432 checklistsJun 8-14: 1.2% of 29978 checklistsJun 15-21: 1.6% of 29457 checklistsJun 22-30: 1.4% of 36072 checklistsJul 1-7: 1.4% of 28857 checklistsJul 8-14: 1.5% of 27224 checklistsJul 15-21: 1.6% of 27629 checklistsJul 22-31: 1.4% of 37318 checklistsAug 1-7: 1.1% of 25893 checklistsAug 8-14: 0.8% of 24870 checklistsAug 15-21: 0.8% of 24035 checklistsAug 22-31: 0.8% of 35691 checklistsSep 1-7: 0.8% of 27068 checklistsSep 8-14: 0.8% of 26709 checklistsSep 15-21: 1.0% of 26098 checklistsSep 22-30: 1.4% of 31550 checklistsOct 1-7: 1.9% of 24110 checklistsOct 8-14: 1.7% of 23352 checklistsOct 15-21: 1.6% of 21895 checklistsOct 22-31: 1.4% of 28319 checklistsNov 1-7: 1.7% of 21698 checklistsNov 8-14: 1.7% of 21061 checklistsNov 15-21: 2.1% of 19855 checklistsNov 22-30: 2.0% of 25798 checklistsDec 1-7: 2.3% of 18626 checklistsDec 8-14: 2.5% of 19004 checklistsDec 15-21: 2.8% of 23103 checklistsDec 22-31: 2.8% of 30802 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 Colorado 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 Colorado

Best counties

Share of checklists at the peak
  1. Mineral CountyBest mid March · 14 checklists that week, 1,750 in all24%
  2. La Plata CountyBest early January · 488 checklists that week, 21,744 in all22%
  3. Gunnison CountyBest mid December · 55 checklists that week, 9,894 in all21%
  4. Garfield CountyBest the second week of January · 197 checklists that week, 12,156 in all18%
  5. Routt CountyBest late January · 129 checklists that week, 10,504 in all17%
  6. Archuleta CountyBest the second week of January · 77 checklists that week, 10,365 in all17%

Best spots

Share of checklists at the peak
  1. Gateway Natural AreaLarimer County, best late February · 29 checklists that week, 665 in all89%
  2. Loomis IILarimer County, best late February · 21 checklists that week, 718 in all81%
  3. Lair o' the Bear ParkJefferson County, best late December · 21 checklists that week, 1,259 in all77%
  4. Huck Finn PondLa Plata County, best late December · 58 checklists that week, 2,708 in all76%
  5. Red Rocks Park (Bear Creek Canyon)Jefferson County, best early April · 21 checklists that week, 666 in all69%
  6. Hallam LakePitkin County, best the second week of November · 21 checklists that week, 1,206 in all63%

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

Best time of day

In Colorado, the American Dipper is most often listed on checklists started between 1 and 3 pm (2.0% of those checklists).

0%1%2%3%12 am: too few checklists (512) to judge1 am: too few checklists (468) to judge2 am: too few checklists (513) to judge3 am: too few checklists (656) to judge4 am: too few checklists (1918) to judge5 am: too few checklists (16045) to judge6 am: 1.0% of 71991 checklists7 am: 1.3% of 159189 checklists8 am: 1.6% of 177206 checklists9 am: 2.0% of 165269 checklists10 am: 1.8% of 141029 checklists11 am: 1.9% of 115283 checklists12 pm: 1.9% of 96068 checklists1 pm: 2.0% of 89512 checklists2 pm: 2.1% of 86319 checklists3 pm: 1.9% of 82496 checklists4 pm: 1.5% of 71648 checklists5 pm: 1.3% of 52445 checklists6 pm: 1.0% of 40199 checklists7 pm: too few checklists (24246) to judge8 pm: too few checklists (7986) to judge9 pm: too few checklists (2004) to judge10 pm: too few checklists (888) to judge11 pm: too few checklists (450) 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
January3.4%2.8%2.9%3.0%
February3.2%2.7%2.4%2.7%
March2.4%2.1%1.9%1.7%
April1.6%1.4%1.0%1.0%
May0.8%1.0%1.1%1.2%
June1.1%1.2%1.6%1.4%
July1.4%1.5%1.6%1.4%
August1.1%0.8%0.8%0.8%
September0.8%0.8%1.0%1.4%
October1.9%1.7%1.6%1.4%
November1.7%1.7%2.1%2.0%
December2.3%2.5%2.8%2.8%

Neighboring states

  • Wyoming: arrives early May, 18 weeks earlier than Colorado
  • Utah: year-round, peaks late June
  • South Dakota: arrives mid May, 16 weeks earlier than Colorado
  • Montana: year-round, peaks the second week of July

Common questions

When do American Dippers arrive in Colorado?
American Dippers are winter birds in Colorado: the first arrive in mid September, they are common by late September, peak in the second week of January (3.1% of checklists), and most are gone by late July.
When do American Dippers leave Colorado?
Most American Dippers have left Colorado by late July, when reports fall below half their usual rate. Stragglers are still reported until the second week of August.
When is the best time to see a American Dipper in Colorado?
The American Dipper is reported most often in the second week of January, on about 3.1% of Colorado checklists.
Where in Colorado are American Dippers seen most often?
By county, Mineral County, La Plata County, and Gunnison County have the highest peak reporting rates for the American Dipper (counties with at least 200 checklists).