WhenToBird

Circus hudsonius · Accipitridae

When Do Northern Harriers Arrive in Louisiana?

Northern Harriers are winter birds in Louisiana: the first arrive in late September, they are common by mid October, peak in early November (12% of checklists), and most are gone by mid March.

When to look

First arrivalsSep 22-30late September
Common byOct 15-21mid October
PeakNov 1-7early November
Most gone byMar 15-21mid March

Best: early November. First arrivals late September; most are gone by mid March. Peak: on about 12% of Louisiana 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. Seprare
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%5%10%15%Jan 1-7: 9.8% of 8384 checklistsJan 8-14: 8.7% of 6265 checklistsJan 15-21: 8.8% of 6825 checklistsJan 22-31: 8.6% of 8776 checklistsFeb 1-7: 8.1% of 5956 checklistsFeb 8-14: 6.6% of 6291 checklistsFeb 15-21: 5.4% of 8044 checklistsFeb 22-28: 7.4% of 5946 checklistsMar 1-7: 6.5% of 5981 checklistsMar 8-14: 5.6% of 6307 checklistsMar 15-21: 4.9% of 6747 checklistsMar 22-31: 4.2% of 10487 checklistsApr 1-7: 3.5% of 8037 checklistsApr 8-14: 2.0% of 9577 checklistsApr 15-21: 1.4% of 11372 checklistsApr 22-30: 0.7% of 14344 checklistsMay 1-7: 0.1% of 8193 checklistsMay 8-14: 0.1% of 6823 checklistsMay 15-21: 0% of 4818 checklistsMay 22-31: 0% of 6206 checklistsJun 1-7: 0% of 3660 checklistsJun 8-14: 0% of 3455 checklistsJun 15-21: 0% of 3084 checklistsJun 22-30: 0% of 3904 checklistsJul 1-7: 0% of 3240 checklistsJul 8-14: 0% of 3235 checklistsJul 15-21: 0% of 3167 checklistsJul 22-31: 0% of 4328 checklistsAug 1-7: 0% of 3192 checklistsAug 8-14: 0% of 3394 checklistsAug 15-21: 0% of 3502 checklistsAug 22-31: 0% of 5658 checklistsSep 1-7: 0.1% of 4366 checklistsSep 8-14: 0.2% of 4648 checklistsSep 15-21: 0.3% of 4369 checklistsSep 22-30: 1.6% of 6418 checklistsOct 1-7: 2.3% of 5375 checklistsOct 8-14: 3.3% of 6213 checklistsOct 15-21: 4.8% of 5553 checklistsOct 22-31: 12% of 8879 checklistsNov 1-7: 13% of 6231 checklistsNov 8-14: 10% of 5011 checklistsNov 15-21: 9.3% of 4856 checklistsNov 22-30: 10% of 6696 checklistsDec 1-7: 8.9% of 4530 checklistsDec 8-14: 9.9% of 4883 checklistsDec 15-21: 12% of 5833 checklistsDec 22-31: 8.6% of 9940 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 Louisiana 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 Louisiana

Best counties

Share of checklists at the peak
  1. Red River ParishBest late November · 13 checklists that week, 998 in all69%
  2. Jefferson Davis ParishBest late December · 54 checklists that week, 2,828 in all60%
  3. Cameron ParishBest the second week of December · 326 checklists that week, 17,943 in all46%
  4. Madison ParishBest late January · 23 checklists that week, 491 in all43%
  5. Vermilion ParishBest early December · 36 checklists that week, 3,499 in all41%
  6. Morehouse ParishBest late January · 22 checklists that week, 638 in all41%

Best spots

Share of checklists at the peak
  1. Big Branch Marsh National Wildlife Refuge (Bayou Cochon)St. Tammany Parish, best the second week of December · 21 checklists that week, 1,384 in all80%
  2. Lacassine National Wildlife RefugeCameron Parish, best early November · 36 checklists that week, 438 in all73%
  3. Savanne Neuville IslandCameron Parish, best early January · 67 checklists that week, 1,491 in all71%

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

Best time of day

In Louisiana, the Northern Harrier is most often listed on checklists started between 1 and 3 pm (6.2% of those checklists).

0%2%4%6%8%12 am: too few checklists (110) to judge1 am: too few checklists (95) to judge2 am: too few checklists (78) to judge3 am: too few checklists (145) to judge4 am: too few checklists (266) to judge5 am: too few checklists (2981) to judge6 am: 3.3% of 21115 checklists7 am: 3.7% of 38843 checklists8 am: 4.3% of 36306 checklists9 am: 5.1% of 31934 checklists10 am: 5.7% of 27208 checklists11 am: 5.6% of 20733 checklists12 pm: 5.9% of 18505 checklists1 pm: 6.0% of 17383 checklists2 pm: 6.3% of 17422 checklists3 pm: 5.8% of 17005 checklists4 pm: 4.4% of 17170 checklists5 pm: 2.5% of 12536 checklists6 pm: 0.9% of 8080 checklists7 pm: too few checklists (3798) to judge8 pm: too few checklists (676) to judge9 pm: too few checklists (311) to judge10 pm: too few checklists (206) to judge11 pm: too few checklists (93) 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
January9.8%8.7%8.8%8.6%
February8.1%6.6%5.4%7.4%
March6.5%5.6%4.9%4.2%
April3.5%2.0%1.4%0.7%
May0.1%0.1%0%0%
June0%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0.1%0.2%0.3%1.6%
October2.3%3.3%4.8%12%
November13%10%9.3%10%
December8.9%9.9%12%8.6%

Neighboring states

  • Mississippi: arrives late September, in the same week than Louisiana
  • Alabama: arrives late September, in the same week than Louisiana
  • Texas: arrives mid September, 1 week earlier than Louisiana
  • Arkansas: arrives late September, in the same week than Louisiana

Common questions

When do Northern Harriers arrive in Louisiana?
Northern Harriers are winter birds in Louisiana: the first arrive in late September, they are common by mid October, peak in early November (12% of checklists), and most are gone by mid March.
When do Northern Harriers leave Louisiana?
Most Northern Harriers have left Louisiana by mid March, when reports fall below half their usual rate. Stragglers are still reported until mid April.
When is the best time to see a Northern Harrier in Louisiana?
The Northern Harrier is reported most often in early November, on about 12% of Louisiana checklists.
Where in Louisiana are Northern Harriers seen most often?
By county, Red River Parish, Jefferson Davis Parish, and Cameron Parish have the highest peak reporting rates for the Northern Harrier (counties with at least 200 checklists).