WhenToBird

Nyctanassa violacea · Ardeidae

When Do Yellow-crowned Night Herons Arrive in Connecticut?

Adult Yellow-crowned Night-Heron
Photo: Michelle W. （鍾偉瑋）, CC BY 4.0 via iNaturalist

Yellow-crowned Night Herons reach Connecticut in the second week of May, are common by late May, peak in early August (5.8% of checklists), and most are gone by the second week of October.

When to look

First arrivalsMay 8-14the second week of May
Common byMay 22-31late May
PeakAug 1-7early August
Most gone byOct 8-14the second week of October

Best: early August. First arrivals the second week of May; most are gone by the second week of October. Peak: on about 5.8% of Connecticut checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marrare
  4. Aprrare
  5. Mayuncommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Seppeak season
  10. Octcommon
  11. Novrare
  12. Decnot usually seen

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

0%2%4%6%Jan 1-7: 0.1% of 18950 checklistsJan 8-14: 0% of 13676 checklistsJan 15-21: 0.1% of 13377 checklistsJan 22-31: 0% of 17004 checklistsFeb 1-7: 0% of 10218 checklistsFeb 8-14: 0% of 11568 checklistsFeb 15-21: 0% of 15916 checklistsFeb 22-28: 0% of 11413 checklistsMar 1-7: 0% of 10754 checklistsMar 8-14: 0% of 12051 checklistsMar 15-21: 0.1% of 12616 checklistsMar 22-31: 0.4% of 17801 checklistsApr 1-7: 0.8% of 13186 checklistsApr 8-14: 0.8% of 14428 checklistsApr 15-21: 0.8% of 14738 checklistsApr 22-30: 0.6% of 21753 checklistsMay 1-7: 0.8% of 22494 checklistsMay 8-14: 0.9% of 23363 checklistsMay 15-21: 1.6% of 20219 checklistsMay 22-31: 2.2% of 20778 checklistsJun 1-7: 2.4% of 12234 checklistsJun 8-14: 2.3% of 12491 checklistsJun 15-21: 2.4% of 10856 checklistsJun 22-30: 2.9% of 11964 checklistsJul 1-7: 2.9% of 9437 checklistsJul 8-14: 3.5% of 8599 checklistsJul 15-21: 4.6% of 8252 checklistsJul 22-31: 6.0% of 11329 checklistsAug 1-7: 5.8% of 8116 checklistsAug 8-14: 5.5% of 8051 checklistsAug 15-21: 5.5% of 8502 checklistsAug 22-31: 5.7% of 13673 checklistsSep 1-7: 5.6% of 9873 checklistsSep 8-14: 4.7% of 9735 checklistsSep 15-21: 3.7% of 10120 checklistsSep 22-30: 2.7% of 12543 checklistsOct 1-7: 2.5% of 10735 checklistsOct 8-14: 2.2% of 10869 checklistsOct 15-21: 1.2% of 10436 checklistsOct 22-31: 0.8% of 13808 checklistsNov 1-7: 0.4% of 10507 checklistsNov 8-14: 0.1% of 9827 checklistsNov 15-21: 0.2% of 9904 checklistsNov 22-30: 0.2% of 13396 checklistsDec 1-7: 0.2% of 8974 checklistsDec 8-14: 0.3% of 9468 checklistsDec 15-21: 0.1% of 11614 checklistsDec 22-31: 0.1% of 16616 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 Connecticut 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 Connecticut

Best counties

Share of checklists at the peak
  1. New Haven CountyBest early August · 1925 checklists that week, 139,721 in all16%
  2. Fairfield CountyBest late July · 2415 checklists that week, 139,848 in all8.8%
  3. Middlesex CountyBest mid August · 516 checklists that week, 39,919 in all3.8%
  4. New London CountyBest the second week of August · 869 checklists that week, 65,205 in all2.5%
  5. Hartford CountyBest the second week of August · 1289 checklists that week, 105,735 in all0.1%
  6. Litchfield CountyBest the second week of April · 1705 checklists that week, 69,766 in all0.1%

Best spots

Share of checklists at the peak
  1. Brewsters PondFairfield County, best mid August · 28 checklists that week, 708 in all96%
  2. Mac's HarborFairfield County, best early May · 26 checklists that week, 412 in all94%
  3. Frash Pond (Great Meadows)Fairfield County, best the second week of April · 46 checklists that week, 661 in all93%
  4. Beard Cove (historical)New Haven County, best late August · 410 checklists that week, 8,925 in all78%
  5. GreenwayFairfield County, best late July · 30 checklists that week, 712 in all66%

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

Best time of day

In Connecticut, the Yellow-crowned Night Heron is most often listed on checklists started between 5 and 7 pm (1.9% of those checklists).

0%0.5%1%1.5%2%12 am: too few checklists (325) to judge1 am: too few checklists (367) to judge2 am: too few checklists (488) to judge3 am: too few checklists (792) to judge4 am: too few checklists (2722) to judge5 am: too few checklists (9489) to judge6 am: 1.5% of 33657 checklists7 am: 1.1% of 62964 checklists8 am: 1.2% of 70645 checklists9 am: 1.6% of 64870 checklists10 am: 1.7% of 58827 checklists11 am: 1.7% of 51689 checklists12 pm: 1.7% of 45288 checklists1 pm: 1.5% of 44765 checklists2 pm: 1.6% of 44173 checklists3 pm: 1.4% of 41979 checklists4 pm: 1.6% of 33219 checklists5 pm: 1.8% of 24828 checklists6 pm: 2.0% of 15856 checklists7 pm: too few checklists (8126) to judge8 pm: too few checklists (1994) to judge9 pm: too few checklists (533) to judge10 pm: too few checklists (349) to judge11 pm: too few checklists (286) 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
January0.1%0%0.1%0%
February0%0%0%0%
March0%0%0.1%0.4%
April0.8%0.8%0.8%0.6%
May0.8%0.9%1.6%2.2%
June2.4%2.3%2.4%2.9%
July2.9%3.5%4.6%6.0%
August5.8%5.5%5.5%5.7%
September5.6%4.7%3.7%2.7%
October2.5%2.2%1.2%0.8%
November0.4%0.1%0.2%0.2%
December0.2%0.3%0.1%0.1%

Neighboring states

  • Rhode Island: arrives early July, 7 weeks later than Connecticut
  • Massachusetts: arrives mid June, 5 weeks later than Connecticut
  • New Jersey: arrives mid April, 3 weeks earlier than Connecticut
  • New York: arrives the second week of May, in the same week than Connecticut

Common questions

When do Yellow-crowned Night Herons arrive in Connecticut?
Yellow-crowned Night Herons reach Connecticut in the second week of May, are common by late May, peak in early August (5.8% of checklists), and most are gone by the second week of October.
When do Yellow-crowned Night Herons leave Connecticut?
Most Yellow-crowned Night Herons have left Connecticut by the second week of October, when reports fall below half their usual rate. Stragglers are still reported until mid October.
When is the best time to see a Yellow-crowned Night Heron in Connecticut?
The Yellow-crowned Night Heron is reported most often in early August, on about 5.8% of Connecticut checklists.
Where in Connecticut are Yellow-crowned Night Herons seen most often?
By county, New Haven County, Fairfield County, and Middlesex County have the highest peak reporting rates for the Yellow-crowned Night Heron (counties with at least 200 checklists).