WhenToBird

Nyctanassa violacea · Ardeidae

When Do Yellow-crowned Night Herons Arrive in Massachusetts?

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

Yellow-crowned Night Herons arrive in Massachusetts in mid June, peak in mid August (1.3% of checklists), and most are gone by late September.

When to look

First arrivalsJun 15-21mid June
Common byJun 15-21mid June
PeakAug 15-21mid August
Most gone bySep 22-30late September

Best: mid August. First arrivals mid June; most are gone by late September. Peak: on about 1.3% of Massachusetts checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Apruncommon
  5. Mayuncommon
  6. Jununcommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octuncommon
  11. Novnot usually seen
  12. Decnot usually seen

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

0%0.5%1%1.5%Jan 1-7: 0.1% of 43252 checklistsJan 8-14: 0% of 30096 checklistsJan 15-21: 0% of 28760 checklistsJan 22-31: 0% of 38135 checklistsFeb 1-7: 0% of 26442 checklistsFeb 8-14: 0% of 29034 checklistsFeb 15-21: 0% of 37383 checklistsFeb 22-28: 0% of 29977 checklistsMar 1-7: 0% of 29175 checklistsMar 8-14: 0% of 32399 checklistsMar 15-21: 0% of 34444 checklistsMar 22-31: 0.1% of 49126 checklistsApr 1-7: 0.1% of 36456 checklistsApr 8-14: 0.1% of 40908 checklistsApr 15-21: 0.1% of 42078 checklistsApr 22-30: 0.3% of 56465 checklistsMay 1-7: 0.2% of 56994 checklistsMay 8-14: 0.2% of 64079 checklistsMay 15-21: 0.3% of 52020 checklistsMay 22-31: 0.3% of 55402 checklistsJun 1-7: 0.3% of 30682 checklistsJun 8-14: 0.3% of 27557 checklistsJun 15-21: 0.3% of 26163 checklistsJun 22-30: 0.5% of 29576 checklistsJul 1-7: 0.3% of 23931 checklistsJul 8-14: 0.4% of 22389 checklistsJul 15-21: 0.5% of 22365 checklistsJul 22-31: 0.8% of 32631 checklistsAug 1-7: 1.1% of 25133 checklistsAug 8-14: 1.2% of 24610 checklistsAug 15-21: 1.3% of 25350 checklistsAug 22-31: 1.3% of 37198 checklistsSep 1-7: 1.1% of 27402 checklistsSep 8-14: 0.9% of 27700 checklistsSep 15-21: 0.7% of 28398 checklistsSep 22-30: 0.5% of 34646 checklistsOct 1-7: 0.4% of 28620 checklistsOct 8-14: 0.1% of 30144 checklistsOct 15-21: 0.1% of 28893 checklistsOct 22-31: 0.1% of 38869 checklistsNov 1-7: 0.1% of 29782 checklistsNov 8-14: 0% of 27582 checklistsNov 15-21: 0% of 26642 checklistsNov 22-30: 0% of 34390 checklistsDec 1-7: 0% of 25164 checklistsDec 8-14: 0% of 24892 checklistsDec 15-21: 0% of 29022 checklistsDec 22-31: 0% of 44323 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 Massachusetts 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 Massachusetts

Best counties

Share of checklists at the peak
  1. Nantucket CountyBest late July · 552 checklists that week, 23,895 in all3.9%
  2. Barnstable CountyBest early September · 4569 checklists that week, 215,188 in all3.2%
  3. Essex CountyBest late August · 4347 checklists that week, 213,973 in all2.6%
  4. Bristol CountyBest the second week of August · 852 checklists that week, 65,262 in all2.6%
  5. Dukes CountyBest mid August · 514 checklists that week, 23,670 in all1.9%
  6. Plymouth CountyBest the second week of August · 1294 checklists that week, 89,282 in all1.8%

Best spots

Share of checklists at the peak
  1. Brick Factory SanctuaryBarnstable County, best mid August · 45 checklists that week, 977 in all78%
  2. Perkins ParkEssex County, best the second week of August · 44 checklists that week, 533 in all67%
  3. Salt Pond BayBarnstable County, best early September · 26 checklists that week, 518 in all63%
  4. Hallets MillpondBarnstable County, best mid June · 25 checklists that week, 1,054 in all54%
  5. Blacks Creek Marshes (Pine Island)Norfolk County, best mid August · 21 checklists that week, 303 in all33%
  6. Lewis Lake ParkSuffolk County, best the second week of September · 22 checklists that week, 1,102 in all32%

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

Best time of day

In Massachusetts, the Yellow-crowned Night Heron is most often listed on checklists started between 5 and 7 pm (0.5% of those checklists).

0%0.5%1%12 am: too few checklists (630) to judge1 am: too few checklists (657) to judge2 am: too few checklists (645) to judge3 am: too few checklists (850) to judge4 am: too few checklists (3787) to judge5 am: too few checklists (29743) to judge6 am: 0.4% of 108601 checklists7 am: 0.3% of 186104 checklists8 am: 0.2% of 185905 checklists9 am: 0.2% of 166049 checklists10 am: 0.2% of 150508 checklists11 am: 0.1% of 131024 checklists12 pm: 0.2% of 116804 checklists1 pm: 0.2% of 112055 checklists2 pm: 0.2% of 110246 checklists3 pm: 0.2% of 104376 checklists4 pm: 0.2% of 83736 checklists5 pm: 0.4% of 63723 checklists6 pm: 0.6% of 41435 checklists7 pm: too few checklists (21041) to judge8 pm: too few checklists (5240) to judge9 pm: too few checklists (1722) to judge10 pm: too few checklists (1094) to judge11 pm: too few checklists (704) 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%0%
February0%0%0%0%
March0%0%0%0.1%
April0.1%0.1%0.1%0.3%
May0.2%0.2%0.3%0.3%
June0.3%0.3%0.3%0.5%
July0.3%0.4%0.5%0.8%
August1.1%1.2%1.3%1.3%
September1.1%0.9%0.7%0.5%
October0.4%0.1%0.1%0.1%
November0.1%0%0%0%
December0%0%0%0%

Neighboring states

  • Rhode Island: arrives early July, 2 weeks later than Massachusetts
  • Connecticut: arrives the second week of May, 5 weeks earlier than Massachusetts
  • New York: arrives the second week of May, 5 weeks earlier than Massachusetts
  • New Jersey: arrives mid April, 8 weeks earlier than Massachusetts

Common questions

When do Yellow-crowned Night Herons arrive in Massachusetts?
Yellow-crowned Night Herons arrive in Massachusetts in mid June, peak in mid August (1.3% of checklists), and most are gone by late September.
When do Yellow-crowned Night Herons leave Massachusetts?
Most Yellow-crowned Night Herons have left Massachusetts by late September, when reports fall below half their usual rate.
When is the best time to see a Yellow-crowned Night Heron in Massachusetts?
The Yellow-crowned Night Heron is reported most often in mid August, on about 1.3% of Massachusetts checklists.
Where in Massachusetts are Yellow-crowned Night Herons seen most often?
By county, Nantucket County, Barnstable County, and Essex County have the highest peak reporting rates for the Yellow-crowned Night Heron (counties with at least 200 checklists).