WhenToBird

Mareca strepera · Anatidae

When Do Gadwalls Arrive in Montana?

Adult Gadwall
Photo: Anne Parsons, CC0 1.0 via iNaturalist

Gadwalls reach Montana in late February, are common by mid March, peak in late April (19% of checklists), and most are gone by mid November.

When to look

First arrivalsFeb 22-28late February
Common byMar 15-21mid March
PeakApr 22-30late April
Most gone byNov 15-21mid November

Best: late April. First arrivals late February; most are gone by mid November. Peak: on about 19% of Montana checklists.

  1. Janrare
  2. Febrare
  3. Marcommon
  4. Aprpeak season
  5. Maypeak season
  6. Juncommon
  7. Juluncommon
  8. Auguncommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Decuncommon

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

0%5%10%15%20%Jan 1-7: 3.2% of 7987 checklistsJan 8-14: 2.3% of 5561 checklistsJan 15-21: 2.1% of 5613 checklistsJan 22-31: 2.3% of 7881 checklistsFeb 1-7: 2.0% of 5018 checklistsFeb 8-14: 1.9% of 5598 checklistsFeb 15-21: 1.9% of 7247 checklistsFeb 22-28: 2.7% of 5531 checklistsMar 1-7: 3.8% of 6110 checklistsMar 8-14: 4.2% of 6623 checklistsMar 15-21: 5.5% of 7687 checklistsMar 22-31: 8.7% of 11095 checklistsApr 1-7: 12% of 7774 checklistsApr 8-14: 15% of 8785 checklistsApr 15-21: 18% of 9684 checklistsApr 22-30: 19% of 13805 checklistsMay 1-7: 18% of 11847 checklistsMay 8-14: 17% of 13547 checklistsMay 15-21: 14% of 13019 checklistsMay 22-31: 13% of 20456 checklistsJun 1-7: 11% of 12993 checklistsJun 8-14: 10% of 11594 checklistsJun 15-21: 8.5% of 11159 checklistsJun 22-30: 7.3% of 13786 checklistsJul 1-7: 5.3% of 9584 checklistsJul 8-14: 4.5% of 9078 checklistsJul 15-21: 3.9% of 7905 checklistsJul 22-31: 4.2% of 10906 checklistsAug 1-7: 4.6% of 7335 checklistsAug 8-14: 4.7% of 6868 checklistsAug 15-21: 5.7% of 6866 checklistsAug 22-31: 6.0% of 10076 checklistsSep 1-7: 6.2% of 7670 checklistsSep 8-14: 7.1% of 7490 checklistsSep 15-21: 7.7% of 6804 checklistsSep 22-30: 8.4% of 8016 checklistsOct 1-7: 8.6% of 5996 checklistsOct 8-14: 10% of 6156 checklistsOct 15-21: 11% of 5742 checklistsOct 22-31: 10% of 7790 checklistsNov 1-7: 11% of 5353 checklistsNov 8-14: 7.7% of 5475 checklistsNov 15-21: 5.8% of 4603 checklistsNov 22-30: 4.7% of 6067 checklistsDec 1-7: 3.5% of 4362 checklistsDec 8-14: 3.9% of 4467 checklistsDec 15-21: 3.2% of 5328 checklistsDec 22-31: 2.5% 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 early May · 286 checklists that week, 8,732 in all53%
  2. Teton CountyBest late April · 81 checklists that week, 2,579 in all48%
  3. Sheridan CountyBest the second week of April · 30 checklists that week, 2,316 in all47%
  4. Hill CountyBest late April · 48 checklists that week, 988 in all47%
  5. Rosebud CountyBest mid April · 11 checklists that week, 795 in all46%
  6. Fallon CountyBest early May · 28 checklists that week, 542 in all43%

Best spots

Share of checklists at the peak
  1. Lee Metcalf National Wildlife Refuge (northeast)Ravalli County, best early May · 20 checklists that week, 838 in all96%
  2. Warm Springs Wildlife Management Area (05N10W24ABBC01 Spring)Deer Lodge County, best early May · 26 checklists that week, 564 in all92%
  3. Cottonwood ReservoirPark County, best mid May · 23 checklists that week, 638 in all92%
  4. Upper Holter LakeLewis and Clark County, best late October · 26 checklists that week, 332 in all91%

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

Best time of day

In Montana, the Gadwall is most often listed on checklists started between 5 and 7 pm (11% of those checklists).

0%5%10%15%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: 8.6% of 12719 checklists7 am: 7.5% of 31202 checklists8 am: 7.3% of 47646 checklists9 am: 8.5% of 44624 checklists10 am: 8.3% of 40704 checklists11 am: 8.5% of 33825 checklists12 pm: 8.5% of 29407 checklists1 pm: 8.5% of 27959 checklists2 pm: 8.7% of 26928 checklists3 pm: 8.6% of 25313 checklists4 pm: 9.0% of 22151 checklists5 pm: 10% of 16884 checklists6 pm: 11% of 13780 checklists7 pm: 8.3% 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
January3.2%2.3%2.1%2.3%
February2.0%1.9%1.9%2.7%
March3.8%4.2%5.5%8.7%
April12%15%18%19%
May18%17%14%13%
June11%10%8.5%7.3%
July5.3%4.5%3.9%4.2%
August4.6%4.7%5.7%6.0%
September6.2%7.1%7.7%8.4%
October8.6%10%11%10%
November11%7.7%5.8%4.7%
December3.5%3.9%3.2%2.5%

Neighboring states

  • Idaho: year-round, peaks mid April
  • Wyoming: arrives late February, in the same week than Montana
  • Utah: arrives late August, 24 weeks earlier than Montana
  • Washington: year-round, peaks late April

Common questions

When do Gadwalls arrive in Montana?
Gadwalls reach Montana in late February, are common by mid March, peak in late April (19% of checklists), and most are gone by mid November.
When do Gadwalls leave Montana?
Most Gadwalls have left Montana by mid November, when reports fall below half their usual rate. Stragglers are still reported until the second week of January.
When is the best time to see a Gadwall in Montana?
The Gadwall is reported most often in late April, on about 19% of Montana checklists.
Where in Montana are Gadwalls seen most often?
By county, Deer Lodge County, Teton County, and Sheridan County have the highest peak reporting rates for the Gadwall (counties with at least 200 checklists).