WhenToBird

Circus hudsonius · Accipitridae

When Do Northern Harriers Arrive in Maryland?

Northern Harriers are winter birds in Maryland: the first arrive in the second week of September, they are common by mid September, peak in the second week of November (4.1% of checklists), and most are gone by the second week of April.

When to look

First arrivalsSep 8-14the second week of September
Common bySep 15-21mid September
PeakNov 8-14the second week of November
Most gone byApr 8-14the second week of April

Best: the second week of November. First arrivals the second week of September; most are gone by the second week of April. Peak: on about 4.1% of Maryland checklists.

  1. Janpeak season
  2. Febcommon
  3. Marcommon
  4. Aprcommon
  5. Mayuncommon
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augrare
  9. Sepcommon
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%2%4%6%Jan 1-7: 2.6% of 28716 checklistsJan 8-14: 3.2% of 21449 checklistsJan 15-21: 2.7% of 21267 checklistsJan 22-31: 2.8% of 29144 checklistsFeb 1-7: 2.9% of 21347 checklistsFeb 8-14: 2.2% of 22166 checklistsFeb 15-21: 2.4% of 29986 checklistsFeb 22-28: 3.1% of 22427 checklistsMar 1-7: 2.4% of 21389 checklistsMar 8-14: 2.3% of 22192 checklistsMar 15-21: 2.0% of 22823 checklistsMar 22-31: 2.1% of 33720 checklistsApr 1-7: 2.0% of 25513 checklistsApr 8-14: 1.9% of 27718 checklistsApr 15-21: 1.3% of 29328 checklistsApr 22-30: 1.1% of 42595 checklistsMay 1-7: 0.7% of 38532 checklistsMay 8-14: 0.6% of 42722 checklistsMay 15-21: 0.3% of 31936 checklistsMay 22-31: 0.2% of 36903 checklistsJun 1-7: 0.1% of 23191 checklistsJun 8-14: 0.1% of 21853 checklistsJun 15-21: 0.1% of 21000 checklistsJun 22-30: 0.1% of 25133 checklistsJul 1-7: 0.1% of 18715 checklistsJul 8-14: 0.1% of 16376 checklistsJul 15-21: 0.1% of 15793 checklistsJul 22-31: 0.1% of 21969 checklistsAug 1-7: 0.1% of 16013 checklistsAug 8-14: 0.2% of 15249 checklistsAug 15-21: 0.3% of 15674 checklistsAug 22-31: 0.5% of 24925 checklistsSep 1-7: 0.8% of 19808 checklistsSep 8-14: 1.1% of 18513 checklistsSep 15-21: 1.8% of 21901 checklistsSep 22-30: 2.0% of 22901 checklistsOct 1-7: 2.5% of 19111 checklistsOct 8-14: 2.6% of 18482 checklistsOct 15-21: 2.9% of 17380 checklistsOct 22-31: 3.4% of 23992 checklistsNov 1-7: 3.9% of 17915 checklistsNov 8-14: 4.7% of 18905 checklistsNov 15-21: 3.5% of 16259 checklistsNov 22-30: 3.8% of 22852 checklistsDec 1-7: 3.2% of 16108 checklistsDec 8-14: 3.1% of 16512 checklistsDec 15-21: 3.7% of 18952 checklistsDec 22-31: 3.7% of 29728 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 Maryland 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 Maryland

Best counties

Share of checklists at the peak
  1. Somerset CountyBest mid November · 57 checklists that week, 9,451 in all43%
  2. Dorchester CountyBest the second week of November · 513 checklists that week, 26,161 in all34%
  3. Queen Anne's CountyBest mid November · 421 checklists that week, 26,875 in all14%
  4. Kent CountyBest mid November · 315 checklists that week, 13,396 in all12%
  5. Caroline CountyBest mid December · 167 checklists that week, 11,067 in all7.8%
  6. Wicomico CountyBest the second week of December · 110 checklists that week, 12,356 in all7.4%

Best spots

Share of checklists at the peak
  1. Dames Quarter MarshSomerset County, best late February · 23 checklists that week, 694 in all92%
  2. Rumbly PointSomerset County, best early November · 23 checklists that week, 412 in all89%
  3. Deal Island WmaSomerset County, best mid February · 23 checklists that week, 505 in all89%
  4. Fairmount WmaSomerset County, best late December · 24 checklists that week, 123 in all75%
  5. Conquest BeachQueen Anne's County, best mid December · 20 checklists that week, 836 in all75%

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

Best time of day

In Maryland, the Northern Harrier is most often listed on checklists started between 3 and 5 pm (2.3% of those checklists).

0%1%2%3%12 am: too few checklists (486) to judge1 am: too few checklists (451) to judge2 am: too few checklists (447) to judge3 am: too few checklists (766) to judge4 am: too few checklists (2076) to judge5 am: too few checklists (11098) to judge6 am: 1.6% of 56604 checklists7 am: 1.7% of 139255 checklists8 am: 1.6% of 148626 checklists9 am: 1.9% of 126820 checklists10 am: 1.8% of 106973 checklists11 am: 1.9% of 87483 checklists12 pm: 1.9% of 74808 checklists1 pm: 2.0% of 69428 checklists2 pm: 2.1% of 67800 checklists3 pm: 2.2% of 67688 checklists4 pm: 2.4% of 60927 checklists5 pm: 1.6% of 43876 checklists6 pm: 0.7% of 32930 checklists7 pm: too few checklists (19051) to judge8 pm: too few checklists (5708) to judge9 pm: too few checklists (1977) to judge10 pm: too few checklists (1170) to judge11 pm: too few checklists (635) 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
January2.6%3.2%2.7%2.8%
February2.9%2.2%2.4%3.1%
March2.4%2.3%2.0%2.1%
April2.0%1.9%1.3%1.1%
May0.7%0.6%0.3%0.2%
June0.1%0.1%0.1%0.1%
July0.1%0.1%0.1%0.1%
August0.1%0.2%0.3%0.5%
September0.8%1.1%1.8%2.0%
October2.5%2.6%2.9%3.4%
November3.9%4.7%3.5%3.8%
December3.2%3.1%3.7%3.7%

Neighboring states

  • Delaware: arrives mid August, 3 weeks earlier than Maryland
  • Virginia: arrives the second week of September, in the same week than Maryland
  • Pennsylvania: arrives the second week of September, in the same week than Maryland
  • New Jersey: arrives late August, 2 weeks earlier than Maryland

Common questions

When do Northern Harriers arrive in Maryland?
Northern Harriers are winter birds in Maryland: the first arrive in the second week of September, they are common by mid September, peak in the second week of November (4.1% of checklists), and most are gone by the second week of April.
When do Northern Harriers leave Maryland?
Most Northern Harriers have left Maryland by the second week of April, when reports fall below half their usual rate. Stragglers are still reported until late April.
When is the best time to see a Northern Harrier in Maryland?
The Northern Harrier is reported most often in the second week of November, on about 4.1% of Maryland checklists.
Where in Maryland are Northern Harriers seen most often?
By county, Somerset County, Dorchester County, and Queen Anne's County have the highest peak reporting rates for the Northern Harrier (counties with at least 200 checklists).