WhenToBird

Anas platyrhynchos · Anatidae

When Do Mallards Arrive in Idaho?

Adult male Mallard
Photo: euqirneto, CC BY 4.0 via iNaturalist

Mallards are in Idaho all year, but most are here in winter: numbers build from mid October, peak in early April (50% of checklists), and fall back by mid May. In the quietest week (early July) they are still on about 19% of checklists.

When to look

Numbers buildOct 15-21mid October
PeakApr 1-7early April
Fall back byMay 15-21mid May
FewestJul 1-7early July

Best: early April. Here all year; numbers build from mid October and fall back by mid May. Peak: on about 50% of Idaho checklists.

  1. Jancommon
  2. Febpeak season
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Juncommon
  7. Julcommon
  8. Augcommon
  9. Sepcommon
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

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

0%20%40%60%Jan 1-7: 36% of 9357 checklistsJan 8-14: 35% of 6408 checklistsJan 15-21: 35% of 6358 checklistsJan 22-31: 37% of 8601 checklistsFeb 1-7: 37% of 5611 checklistsFeb 8-14: 35% of 6090 checklistsFeb 15-21: 36% of 7973 checklistsFeb 22-28: 42% of 5866 checklistsMar 1-7: 43% of 6144 checklistsMar 8-14: 45% of 6456 checklistsMar 15-21: 46% of 6786 checklistsMar 22-31: 50% of 9539 checklistsApr 1-7: 50% of 7202 checklistsApr 8-14: 49% of 7608 checklistsApr 15-21: 50% of 8069 checklistsApr 22-30: 49% of 10973 checklistsMay 1-7: 47% of 9481 checklistsMay 8-14: 43% of 11318 checklistsMay 15-21: 40% of 9141 checklistsMay 22-31: 34% of 13984 checklistsJun 1-7: 28% of 8897 checklistsJun 8-14: 23% of 8504 checklistsJun 15-21: 22% of 8078 checklistsJun 22-30: 19% of 9665 checklistsJul 1-7: 19% of 7144 checklistsJul 8-14: 19% of 6557 checklistsJul 15-21: 20% of 6430 checklistsJul 22-31: 21% of 8696 checklistsAug 1-7: 24% of 5896 checklistsAug 8-14: 27% of 5643 checklistsAug 15-21: 26% of 6151 checklistsAug 22-31: 29% of 7863 checklistsSep 1-7: 30% of 5769 checklistsSep 8-14: 29% of 5646 checklistsSep 15-21: 29% of 5460 checklistsSep 22-30: 30% of 6363 checklistsOct 1-7: 32% of 4980 checklistsOct 8-14: 34% of 5096 checklistsOct 15-21: 36% of 4878 checklistsOct 22-31: 38% of 6426 checklistsNov 1-7: 40% of 4822 checklistsNov 8-14: 39% of 4999 checklistsNov 15-21: 38% of 4601 checklistsNov 22-30: 39% of 6027 checklistsDec 1-7: 35% of 4180 checklistsDec 8-14: 37% of 4775 checklistsDec 15-21: 37% of 6522 checklistsDec 22-31: 36% of 7792 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 Idaho 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 Idaho

Best counties

Share of checklists at the peak
  1. Lewis CountyBest mid April · 11 checklists that week, 603 in all89%
  2. Gooding CountyBest early January · 179 checklists that week, 3,207 in all78%
  3. Jerome CountyBest late October · 38 checklists that week, 804 in all68%
  4. Bingham CountyBest the second week of November · 12 checklists that week, 1,427 in all68%
  5. Canyon CountyBest the second week of April · 733 checklists that week, 31,704 in all68%
  6. Fremont CountyBest mid December · 18 checklists that week, 5,201 in all68%

Best spots

Share of checklists at the peak
  1. Julius Kleiner Memorial ParkAda County, best early November · 33 checklists that week, 321 in all100%
  2. Clearwater RiverNez Perce County, best mid January · 20 checklists that week, 513 in all100%
  3. Salmon RiverLemhi County, best late March · 21 checklists that week, 206 in all100%
  4. Wilson Springs Access SiteCanyon County, best late October · 22 checklists that week, 1,000 in all100%

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

Best time of day

In Idaho, the Mallard is most often listed on checklists started between 2 and 4 pm (38% of those checklists).

0%10%20%30%40%12 am: too few checklists (180) to judge1 am: too few checklists (176) to judge2 am: too few checklists (169) to judge3 am: too few checklists (164) to judge4 am: too few checklists (450) to judge5 am: too few checklists (2270) to judge6 am: 29% of 9122 checklists7 am: 33% of 22204 checklists8 am: 33% of 38672 checklists9 am: 36% of 38930 checklists10 am: 36% of 37338 checklists11 am: 35% of 33508 checklists12 pm: 36% of 28544 checklists1 pm: 37% of 25774 checklists2 pm: 38% of 24296 checklists3 pm: 39% of 21784 checklists4 pm: 37% of 19051 checklists5 pm: 36% of 14150 checklists6 pm: 35% of 10014 checklists7 pm: 30% of 7495 checklists8 pm: too few checklists (4352) to judge9 pm: too few checklists (1449) to judge10 pm: too few checklists (525) to judge11 pm: too few checklists (208) 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
January36%35%35%37%
February37%35%36%42%
March43%45%46%50%
April50%49%50%49%
May47%43%40%34%
June28%23%22%19%
July19%19%20%21%
August24%27%26%29%
September30%29%29%30%
October32%34%36%38%
November40%39%38%39%
December35%37%37%36%

Neighboring states

  • Montana: arrives the second week of March, 19 weeks later than Idaho
  • Utah: year-round, peaks the second week of April
  • Oregon: year-round, peaks early April
  • Washington: year-round, peaks mid March

Common questions

When do Mallards arrive in Idaho?
Mallards are in Idaho all year, but most are here in winter: numbers build from mid October, peak in early April (50% of checklists), and fall back by mid May. In the quietest week (early July) they are still on about 19% of checklists.
When do Mallards leave Idaho?
Mallards never fully leave Idaho: numbers fall back below half their usual rate by mid May, but some are still reported in every week, about 19% of checklists at the low.
When is the best time to see a Mallard in Idaho?
The Mallard is reported most often in early April, on about 50% of Idaho checklists.
Where in Idaho are Mallards seen most often?
By county, Lewis County, Gooding County, and Jerome County have the highest peak reporting rates for the Mallard (counties with at least 200 checklists).