WhenToBird

Aythya affinis · Anatidae

When Do Lesser Scaups Arrive in Hawaii?

Adult male Lesser Scaup
Photo: Paul Lewis, CC BY 4.0 via iNaturalist

Lesser Scaups are winter birds in Hawaii: they arrive in late October, peak in the second week of November (3.6% of checklists), and most are gone by mid March.

When to look

First arrivalsOct 22-31late October
Common byOct 22-31late October
PeakNov 8-14the second week of November
Most gone byMar 15-21mid March

Best: the second week of November. First arrivals late October; most are gone by mid March. Peak: on about 3.6% of Hawaii checklists.

  1. Janpeak season
  2. Febcommon
  3. Marcommon
  4. Apruncommon
  5. Maynot usually seen
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octcommon
  11. Novpeak season
  12. Decpeak season

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

0%1%2%3%4%Jan 1-7: 3.6% of 5223 checklistsJan 8-14: 3.2% of 4322 checklistsJan 15-21: 2.8% of 4791 checklistsJan 22-31: 2.7% of 6113 checklistsFeb 1-7: 2.3% of 4916 checklistsFeb 8-14: 2.2% of 4778 checklistsFeb 15-21: 2.2% of 5119 checklistsFeb 22-28: 2.4% of 5246 checklistsMar 1-7: 2.3% of 4356 checklistsMar 8-14: 1.4% of 4127 checklistsMar 15-21: 1.5% of 4584 checklistsMar 22-31: 1.4% of 5941 checklistsApr 1-7: 0.4% of 3596 checklistsApr 8-14: 0.4% of 3301 checklistsApr 15-21: 0.4% of 3268 checklistsApr 22-30: 0.1% of 3732 checklistsMay 1-7: 0.1% of 2628 checklistsMay 8-14: 0% of 3151 checklistsMay 15-21: 0% of 2566 checklistsMay 22-31: 0% of 4054 checklistsJun 1-7: 0.1% of 2703 checklistsJun 8-14: 0% of 2731 checklistsJun 15-21: 0.1% of 2826 checklistsJun 22-30: 0% of 3671 checklistsJul 1-7: 0% of 2692 checklistsJul 8-14: 0.1% of 2734 checklistsJul 15-21: 0.1% of 2412 checklistsJul 22-31: 0.1% of 3581 checklistsAug 1-7: 0% of 2426 checklistsAug 8-14: 0% of 2669 checklistsAug 15-21: 0.1% of 2605 checklistsAug 22-31: 0.1% of 3159 checklistsSep 1-7: 0% of 2502 checklistsSep 8-14: 0% of 2975 checklistsSep 15-21: 0.1% of 3090 checklistsSep 22-30: 0.1% of 3424 checklistsOct 1-7: 0.1% of 2897 checklistsOct 8-14: 0.1% of 3420 checklistsOct 15-21: 0.6% of 3802 checklistsOct 22-31: 1.7% of 4531 checklistsNov 1-7: 3.2% of 3215 checklistsNov 8-14: 3.5% of 3704 checklistsNov 15-21: 4.0% of 3216 checklistsNov 22-30: 3.3% of 4153 checklistsDec 1-7: 3.0% of 3627 checklistsDec 8-14: 3.1% of 3710 checklistsDec 15-21: 3.0% of 3731 checklistsDec 22-31: 2.8% of 6597 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 Hawaii 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 Hawaii

Best counties

Share of checklists at the peak
  1. Honolulu CountyBest the second week of November · 900 checklists that week, 47,705 in all5.7%
  2. Hawaii CountyBest the second week of January · 1902 checklists that week, 75,146 in all5.6%
  3. Maui CountyBest the second week of December · 427 checklists that week, 22,729 in all3.1%
  4. Kauai CountyBest mid February · 841 checklists that week, 32,543 in all1.2%

Best spots

Share of checklists at the peak
  1. Lokowaka PondHawaii County, best the second week of December · 20 checklists that week, 799 in all65%
  2. State Department of Land State Resource Management AreaHawaii County, best early December · 38 checklists that week, 2,129 in all48%
  3. Kaloko-Honokohau National Historical ParkHawaii County, best early February · 49 checklists that week, 1,861 in all48%
  4. Wailoa River State Recreation AreaHawaii County, best late December · 61 checklists that week, 1,209 in all46%
  5. Pearl Harbor National Wildlife RefugeHonolulu County, best the second week of November · 82 checklists that week, 2,121 in all43%
  6. Kaloko-Honokohau National Historical Park (southeast)Hawaii County, best mid February · 20 checklists that week, 549 in all31%

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

Best time of day

In Hawaii, the Lesser Scaup is most often listed on checklists started between 3 and 5 pm (1.8% of those checklists).

0%0.5%1%1.5%2%12 am: too few checklists (66) to judge1 am: too few checklists (53) to judge2 am: too few checklists (70) to judge3 am: too few checklists (68) to judge4 am: too few checklists (106) to judge5 am: too few checklists (1548) to judge6 am: 0.7% of 10237 checklists7 am: 1.8% of 17935 checklists8 am: 1.5% of 18565 checklists9 am: 1.5% of 19076 checklists10 am: 1.4% of 18179 checklists11 am: 1.6% of 15530 checklists12 pm: 1.5% of 13069 checklists1 pm: 1.6% of 12798 checklists2 pm: 1.7% of 12698 checklists3 pm: 1.8% of 12213 checklists4 pm: 1.7% of 10921 checklists5 pm: 1.0% of 9437 checklists6 pm: 0.1% of 4360 checklists7 pm: too few checklists (1028) to judge8 pm: too few checklists (316) to judge9 pm: too few checklists (182) to judge10 pm: too few checklists (110) to judge11 pm: too few checklists (50) 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
January3.6%3.2%2.8%2.7%
February2.3%2.2%2.2%2.4%
March2.3%1.4%1.5%1.4%
April0.4%0.4%0.4%0.1%
May0.1%0%0%0%
June0.1%0%0.1%0%
July0%0.1%0.1%0.1%
August0%0%0.1%0.1%
September0%0%0.1%0.1%
October0.1%0.1%0.6%1.7%
November3.2%3.5%4.0%3.3%
December3.0%3.1%3.0%2.8%

Neighboring states

  • California: arrives mid October, 1 week earlier than Hawaii
  • Nevada: arrives mid August, 9 weeks earlier than Hawaii
  • Oregon: arrives late September, 4 weeks earlier than Hawaii
  • Arizona: arrives mid October, 1 week earlier than Hawaii

Common questions

When do Lesser Scaups arrive in Hawaii?
Lesser Scaups are winter birds in Hawaii: they arrive in late October, peak in the second week of November (3.6% of checklists), and most are gone by mid March.
When do Lesser Scaups leave Hawaii?
Most Lesser Scaups have left Hawaii by mid March, when reports fall below half their usual rate. Stragglers are still reported until late March.
When is the best time to see a Lesser Scaup in Hawaii?
The Lesser Scaup is reported most often in the second week of November, on about 3.6% of Hawaii checklists.
Where in Hawaii are Lesser Scaups seen most often?
By county, Honolulu County, Hawaii County, and Maui County have the highest peak reporting rates for the Lesser Scaup (counties with at least 200 checklists).