WhenToBird

Botaurus exilis · Ardeidae

When Do Least Bitterns Arrive in Nevada?

Adult Least Bittern
Photo: William J. Deml, CC BY 4.0 via iNaturalist

Least Bitterns arrive in Nevada in mid April, peak in early August (2.2% of checklists), and most are gone by early February.

When to look

First arrivalsApr 15-21mid April
Common byApr 15-21mid April
PeakAug 1-7early August
Most gone byFeb 1-7early February

Best: early August. First arrivals mid April; most are gone by early February. Peak: on about 2.2% of Nevada checklists.

  1. Januncommon
  2. Febuncommon
  3. Marrare
  4. Apruncommon
  5. Mayuncommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Sepcommon
  10. Octcommon
  11. Novuncommon
  12. Decuncommon

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

0%1%2%3%Jan 1-7: 0.4% of 5121 checklistsJan 8-14: 0.7% of 3908 checklistsJan 15-21: 0.5% of 4000 checklistsJan 22-31: 0.5% of 4991 checklistsFeb 1-7: 0.5% of 3377 checklistsFeb 8-14: 0.5% of 3747 checklistsFeb 15-21: 0.2% of 4852 checklistsFeb 22-28: 0.3% of 3712 checklistsMar 1-7: 0.2% of 3745 checklistsMar 8-14: 0.3% of 3763 checklistsMar 15-21: 0.3% of 4188 checklistsMar 22-31: 0.2% of 6027 checklistsApr 1-7: 0.3% of 4679 checklistsApr 8-14: 0.2% of 4609 checklistsApr 15-21: 0.6% of 4709 checklistsApr 22-30: 0.6% of 6984 checklistsMay 1-7: 0.7% of 5702 checklistsMay 8-14: 0.6% of 5928 checklistsMay 15-21: 0.7% of 5353 checklistsMay 22-31: 0.9% of 7352 checklistsJun 1-7: 0.9% of 4360 checklistsJun 8-14: 0.7% of 4183 checklistsJun 15-21: 0.6% of 3751 checklistsJun 22-30: 1.1% of 4126 checklistsJul 1-7: 1.0% of 3231 checklistsJul 8-14: 1.7% of 3024 checklistsJul 15-21: 1.8% of 2967 checklistsJul 22-31: 2.2% of 4212 checklistsAug 1-7: 1.9% of 2828 checklistsAug 8-14: 2.4% of 3036 checklistsAug 15-21: 2.0% of 3076 checklistsAug 22-31: 1.8% of 4345 checklistsSep 1-7: 1.6% of 3369 checklistsSep 8-14: 1.3% of 3728 checklistsSep 15-21: 1.4% of 3535 checklistsSep 22-30: 1.1% of 5028 checklistsOct 1-7: 0.9% of 3976 checklistsOct 8-14: 1.1% of 3781 checklistsOct 15-21: 0.8% of 3577 checklistsOct 22-31: 0.7% of 4986 checklistsNov 1-7: 0.7% of 3592 checklistsNov 8-14: 0.8% of 3685 checklistsNov 15-21: 0.9% of 3399 checklistsNov 22-30: 0.4% of 4544 checklistsDec 1-7: 0.7% of 3162 checklistsDec 8-14: 0.5% of 3191 checklistsDec 15-21: 0.6% of 3615 checklistsDec 22-31: 0.7% of 5101 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 Nevada 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 Nevada

Best counties

Share of checklists at the peak
  1. Clark CountyBest early August · 910 checklists that week, 80,458 in all6.9%
  2. Lincoln CountyBest late May · 316 checklists that week, 3,842 in all1.6%
  3. Nye CountyBest the second week of April · 461 checklists that week, 17,872 in all0.6%
  4. Esmeralda CountyBest early June · 101 checklists that week, 2,275 in all0.6%

Best spots

Share of checklists at the peak
  1. Bird Viewing PreserveClark County, best mid July · 125 checklists that week, 9,268 in all36%
  2. Robert B. Griffith Water ProjectClark County, best early August · 26 checklists that week, 2,177 in all23%
  3. Pahranagat National Wildlife Refuge (south)Lincoln County, best late May · 25 checklists that week, 178 in all10%
  4. Crystal ReservoirNye County, best late May · 21 checklists that week, 950 in all4.3%

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

Best time of day

In Nevada, the Least Bittern is most often listed on checklists started between 5 and 7 am (2.7% of those checklists).

0%1%2%3%12 am: too few checklists (114) to judge1 am: too few checklists (99) to judge2 am: too few checklists (71) to judge3 am: too few checklists (108) to judge4 am: too few checklists (459) to judge5 am: 2.1% of 4313 checklists6 am: 2.9% of 17070 checklists7 am: 2.0% of 27389 checklists8 am: 0.8% of 24858 checklists9 am: 0.5% of 22012 checklists10 am: 0.3% of 19284 checklists11 am: 0.3% of 15592 checklists12 pm: 0.2% of 12432 checklists1 pm: 0.1% of 11386 checklists2 pm: 0.1% of 11262 checklists3 pm: 0.1% of 10721 checklists4 pm: 0.1% of 9090 checklists5 pm: 0.2% of 6397 checklists6 pm: 0.2% of 5012 checklists7 pm: too few checklists (3026) to judge8 pm: too few checklists (905) to judge9 pm: too few checklists (271) to judge10 pm: too few checklists (164) to judge11 pm: too few checklists (120) 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
January0.4%0.7%0.5%0.5%
February0.5%0.5%0.2%0.3%
March0.2%0.3%0.3%0.2%
April0.3%0.2%0.6%0.6%
May0.7%0.6%0.7%0.9%
June0.9%0.7%0.6%1.1%
July1.0%1.7%1.8%2.2%
August1.9%2.4%2.0%1.8%
September1.6%1.3%1.4%1.1%
October0.9%1.1%0.8%0.7%
November0.7%0.8%0.9%0.4%
December0.7%0.5%0.6%0.7%

Neighboring states

  • Arizona: arrives early March, 6 weeks earlier than Nevada
  • Kansas: arrives mid May, 4 weeks later than Nevada
  • Texas: arrives early April, 2 weeks earlier than Nevada
  • Louisiana: arrives the second week of April, 1 week earlier than Nevada

Common questions

When do Least Bitterns arrive in Nevada?
Least Bitterns arrive in Nevada in mid April, peak in early August (2.2% of checklists), and most are gone by early February.
When do Least Bitterns leave Nevada?
Most Least Bitterns have left Nevada by early February, when reports fall below half their usual rate.
When is the best time to see a Least Bittern in Nevada?
The Least Bittern is reported most often in early August, on about 2.2% of Nevada checklists.
Where in Nevada are Least Bitterns seen most often?
By county, Clark County, Lincoln County, and Nye County have the highest peak reporting rates for the Least Bittern (counties with at least 200 checklists).