WhenToBird

Falco sparverius · Falconidae

When Do American Kestrels Arrive in Colorado?

Adult male American Kestrel
Photo: Jonathan Eisen, CC BY 4.0 via iNaturalist

The American Kestrel is in Colorado all year. It turns up on about 12% of checklists at its peak (the second week of December) and on 6.4% in its quietest week (mid July).

When to look

PresentAll year
Peak weekDec 8-14the second week of December
Quietest weekJul 15-21mid July

Best: the second week of December. Here all year. Peak: on about 12% of Colorado checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Juncommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%5%10%15%Jan 1-7: 13% of 32254 checklistsJan 8-14: 12% of 23278 checklistsJan 15-21: 12% of 22933 checklistsJan 22-31: 11% of 30856 checklistsFeb 1-7: 9.9% of 21464 checklistsFeb 8-14: 8.5% of 22910 checklistsFeb 15-21: 7.7% of 28739 checklistsFeb 22-28: 8.9% of 21833 checklistsMar 1-7: 7.7% of 23066 checklistsMar 8-14: 8.2% of 23783 checklistsMar 15-21: 9.2% of 24797 checklistsMar 22-31: 10% of 38439 checklistsApr 1-7: 11% of 31676 checklistsApr 8-14: 12% of 35092 checklistsApr 15-21: 13% of 36778 checklistsApr 22-30: 11% of 50885 checklistsMay 1-7: 9.7% of 44186 checklistsMay 8-14: 8.6% of 49011 checklistsMay 15-21: 8.2% of 40784 checklistsMay 22-31: 7.8% of 53073 checklistsJun 1-7: 7.8% of 32432 checklistsJun 8-14: 7.4% of 29978 checklistsJun 15-21: 7.2% of 29457 checklistsJun 22-30: 7.0% of 36072 checklistsJul 1-7: 7.4% of 28857 checklistsJul 8-14: 6.4% of 27224 checklistsJul 15-21: 6.5% of 27629 checklistsJul 22-31: 6.2% of 37318 checklistsAug 1-7: 6.8% of 25893 checklistsAug 8-14: 7.5% of 24870 checklistsAug 15-21: 8.3% of 24035 checklistsAug 22-31: 9.1% of 35691 checklistsSep 1-7: 11% of 27068 checklistsSep 8-14: 12% of 26709 checklistsSep 15-21: 11% of 26098 checklistsSep 22-30: 10% of 31550 checklistsOct 1-7: 9.7% of 24110 checklistsOct 8-14: 9.3% of 23352 checklistsOct 15-21: 9.1% of 21895 checklistsOct 22-31: 9.6% of 28319 checklistsNov 1-7: 9.7% of 21698 checklistsNov 8-14: 10% of 21061 checklistsNov 15-21: 10% of 19855 checklistsNov 22-30: 11% of 25798 checklistsDec 1-7: 12% of 18626 checklistsDec 8-14: 12% of 19004 checklistsDec 15-21: 13% of 23103 checklistsDec 22-31: 12% 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. Otero CountyBest the second week of December · 49 checklists that week, 4,404 in all38%
  2. Bent CountyBest early December · 24 checklists that week, 5,275 in all36%
  3. Adams CountyBest early January · 1030 checklists that week, 44,639 in all35%
  4. Dolores CountyBest early September · 22 checklists that week, 2,000 in all32%
  5. Huerfano CountyBest late April · 135 checklists that week, 3,008 in all32%
  6. Logan CountyBest the second week of July · 82 checklists that week, 4,117 in all31%

Best spots

Share of checklists at the peak
  1. Clear Spring Ranch ParkEl Paso County, best late March · 47 checklists that week, 2,355 in all82%
  2. CollinsWeld County, best late February · 22 checklists that week, 990 in all81%
  3. Tamarack Ranch State Wildlife AreaLogan County, best early July · 21 checklists that week, 568 in all74%
  4. Barr Lake (northwest)Adams County, best late November · 42 checklists that week, 2,694 in all72%

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

Best time of day

In Colorado, the American Kestrel is most often listed on checklists started between 8 and 10 am (10% of those checklists).

0%5%10%15%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: 9.4% of 71991 checklists7 am: 9.4% of 159189 checklists8 am: 10% of 177206 checklists9 am: 11% of 165269 checklists10 am: 10% of 141029 checklists11 am: 10% of 115283 checklists12 pm: 9.7% of 96068 checklists1 pm: 9.8% of 89512 checklists2 pm: 9.7% of 86319 checklists3 pm: 9.1% of 82496 checklists4 pm: 8.2% of 71648 checklists5 pm: 7.9% of 52445 checklists6 pm: 7.3% 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
January13%12%12%11%
February9.9%8.5%7.7%8.9%
March7.7%8.2%9.2%10%
April11%12%13%11%
May9.7%8.6%8.2%7.8%
June7.8%7.4%7.2%7.0%
July7.4%6.4%6.5%6.2%
August6.8%7.5%8.3%9.1%
September11%12%11%10%
October9.7%9.3%9.1%9.6%
November9.7%10%10%11%
December12%12%13%12%

Neighboring states

  • Wyoming: summer visitor, peaks late April
  • New Mexico: year-round, peaks early April
  • Utah: all year, most in winter, peaks late December
  • Nebraska: all year, most in spring, peaks the second week of April

Common questions

When do American Kestrels arrive in Colorado?
The American Kestrel is in Colorado all year. It turns up on about 12% of checklists at its peak (the second week of December) and on 6.4% in its quietest week (mid July).
When do American Kestrels leave Colorado?
The American Kestrel does not leave Colorado: it is reported all year, from 6.4% of checklists in mid July to 12% in the second week of December.
When is the best time to see a American Kestrel in Colorado?
The American Kestrel is reported most often in the second week of December, on about 12% of Colorado checklists.
Where in Colorado are American Kestrels seen most often?
By county, Otero County, Bent County, and Adams County have the highest peak reporting rates for the American Kestrel (counties with at least 200 checklists).