WhenToBird

Bucephala albeola · Anatidae

When Do Buffleheads Arrive in Montana?

Adult Bufflehead
Photo: Robert Harris, CC BY 4.0 via iNaturalist

Buffleheads are winter birds in Montana: the first arrive in mid August, they are common by early October, peak in early November (16% of checklists), and most are gone by mid May.

When to look

First arrivalsAug 15-21mid August
Common byOct 1-7early October
PeakNov 1-7early November
Most gone byMay 15-21mid May

Best: early November. First arrivals mid August; most are gone by mid May. Peak: on about 16% of Montana checklists.

  1. Januncommon
  2. Febuncommon
  3. Marcommon
  4. Aprpeak season
  5. Maycommon
  6. Jununcommon
  7. Julrare
  8. Augrare
  9. Sepuncommon
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

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

0%5%10%15%20%Jan 1-7: 6.8% of 7987 checklistsJan 8-14: 5.8% of 5561 checklistsJan 15-21: 6.0% of 5613 checklistsJan 22-31: 6.0% of 7881 checklistsFeb 1-7: 5.2% of 5018 checklistsFeb 8-14: 5.0% of 5598 checklistsFeb 15-21: 4.7% of 7247 checklistsFeb 22-28: 5.0% of 5531 checklistsMar 1-7: 7.1% of 6110 checklistsMar 8-14: 7.4% of 6623 checklistsMar 15-21: 9.1% of 7687 checklistsMar 22-31: 10% of 11095 checklistsApr 1-7: 13% of 7774 checklistsApr 8-14: 14% of 8785 checklistsApr 15-21: 17% of 9684 checklistsApr 22-30: 15% of 13805 checklistsMay 1-7: 9.2% of 11847 checklistsMay 8-14: 7.2% of 13547 checklistsMay 15-21: 4.4% of 13019 checklistsMay 22-31: 3.3% of 20456 checklistsJun 1-7: 2.4% of 12993 checklistsJun 8-14: 2.2% of 11594 checklistsJun 15-21: 1.9% of 11159 checklistsJun 22-30: 1.7% of 13786 checklistsJul 1-7: 1.5% of 9584 checklistsJul 8-14: 1.5% of 9078 checklistsJul 15-21: 1.5% of 7905 checklistsJul 22-31: 1.3% of 10906 checklistsAug 1-7: 1.7% of 7335 checklistsAug 8-14: 2.1% of 6868 checklistsAug 15-21: 2.1% of 6866 checklistsAug 22-31: 2.3% of 10076 checklistsSep 1-7: 2.3% of 7670 checklistsSep 8-14: 2.6% of 7490 checklistsSep 15-21: 2.8% of 6804 checklistsSep 22-30: 3.6% of 8016 checklistsOct 1-7: 4.3% of 5996 checklistsOct 8-14: 7.0% of 6156 checklistsOct 15-21: 12% of 5742 checklistsOct 22-31: 15% of 7790 checklistsNov 1-7: 18% of 5353 checklistsNov 8-14: 16% of 5475 checklistsNov 15-21: 12% of 4603 checklistsNov 22-30: 10% of 6067 checklistsDec 1-7: 7.9% of 4362 checklistsDec 8-14: 8.1% of 4467 checklistsDec 15-21: 7.2% of 5328 checklistsDec 22-31: 5.3% of 6672 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 Montana 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 Montana

Best counties

Share of checklists at the peak
  1. Deer Lodge CountyBest late October · 227 checklists that week, 8,732 in all41%
  2. Pondera CountyBest late October · 11 checklists that week, 659 in all38%
  3. Fallon CountyBest mid October · 10 checklists that week, 542 in all36%
  4. Cascade CountyBest mid November · 187 checklists that week, 16,190 in all35%
  5. Madison CountyBest early November · 69 checklists that week, 7,008 in all31%
  6. Big Horn CountyBest the second week of December · 11 checklists that week, 1,279 in all30%

Best spots

Share of checklists at the peak
  1. Doyles SloughMissoula County, best early January · 24 checklists that week, 347 in all98%
  2. West Bank ParkCascade County, best late October · 24 checklists that week, 691 in all97%
  3. Upper Holter LakeLewis and Clark County, best late October · 26 checklists that week, 332 in all96%
  4. Ducharme Fishing Access SiteLake County, best late November · 25 checklists that week, 354 in all92%
  5. Giant Springs State ParkCascade County, best early January · 23 checklists that week, 1,249 in all91%

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

Best time of day

In Montana, the Bufflehead is most often listed on checklists started between 11 am and 1 pm (7.2% of those checklists).

0%2%4%6%8%12 am: too few checklists (183) to judge1 am: too few checklists (169) to judge2 am: too few checklists (163) to judge3 am: too few checklists (212) to judge4 am: too few checklists (503) to judge5 am: too few checklists (4022) to judge6 am: 4.3% of 12719 checklists7 am: 4.5% of 31202 checklists8 am: 5.6% of 47646 checklists9 am: 6.9% of 44624 checklists10 am: 6.9% of 40704 checklists11 am: 7.2% of 33825 checklists12 pm: 7.1% of 29407 checklists1 pm: 7.1% of 27959 checklists2 pm: 7.1% of 26928 checklists3 pm: 7.0% of 25313 checklists4 pm: 6.7% of 22151 checklists5 pm: 6.1% of 16884 checklists6 pm: 6.3% of 13780 checklists7 pm: 3.5% of 9926 checklists8 pm: too few checklists (5765) to judge9 pm: too few checklists (2099) to judge10 pm: too few checklists (595) to judge11 pm: too few checklists (230) 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
January6.8%5.8%6.0%6.0%
February5.2%5.0%4.7%5.0%
March7.1%7.4%9.1%10%
April13%14%17%15%
May9.2%7.2%4.4%3.3%
June2.4%2.2%1.9%1.7%
July1.5%1.5%1.5%1.3%
August1.7%2.1%2.1%2.3%
September2.3%2.6%2.8%3.6%
October4.3%7.0%12%15%
November18%16%12%10%
December7.9%8.1%7.2%5.3%

Neighboring states

  • Idaho: arrives early August, 2 weeks earlier than Montana
  • Wyoming: arrives mid August, in the same week than Montana
  • Utah: arrives mid October, 8 weeks later than Montana
  • Washington: arrives mid October, 8 weeks later than Montana

Common questions

When do Buffleheads arrive in Montana?
Buffleheads are winter birds in Montana: the first arrive in mid August, they are common by early October, peak in early November (16% of checklists), and most are gone by mid May.
When do Buffleheads leave Montana?
Most Buffleheads have left Montana by mid May, when reports fall below half their usual rate. Stragglers are still reported until the second week of June.
When is the best time to see a Bufflehead in Montana?
The Bufflehead is reported most often in early November, on about 16% of Montana checklists.
Where in Montana are Buffleheads seen most often?
By county, Deer Lodge County, Pondera County, and Fallon County have the highest peak reporting rates for the Bufflehead (counties with at least 200 checklists).