WhenToBird

Chroicocephalus philadelphia · Laridae

When Do Bonaparte's Gulls Arrive in Louisiana?

Adult Bonaparte's Gull
Photo: Kevin Krebs, CC BY 4.0 via iNaturalist

Bonaparte's Gulls are winter birds in Louisiana: they arrive in early December, peak in mid January (1.4% of checklists), and most are gone by early April.

When to look

First arrivalsDec 1-7early December
Common byDec 1-7early December
PeakJan 15-21mid January
Most gone byApr 1-7early April

Best: mid January. First arrivals early December; most are gone by early April. Peak: on about 1.4% of Louisiana checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Aprcommon
  5. Mayrare
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octnot usually seen
  11. Novuncommon
  12. Decpeak season

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

0%0.5%1%1.5%2%Jan 1-7: 1.3% of 8384 checklistsJan 8-14: 1.6% of 6265 checklistsJan 15-21: 1.3% of 6825 checklistsJan 22-31: 1.4% of 8776 checklistsFeb 1-7: 1.3% of 5956 checklistsFeb 8-14: 1.1% of 6291 checklistsFeb 15-21: 1.2% of 8044 checklistsFeb 22-28: 0.9% of 5946 checklistsMar 1-7: 1.1% of 5981 checklistsMar 8-14: 1.0% of 6307 checklistsMar 15-21: 0.7% of 6747 checklistsMar 22-31: 0.9% of 10487 checklistsApr 1-7: 0.6% of 8037 checklistsApr 8-14: 0.4% of 9577 checklistsApr 15-21: 0.1% of 11372 checklistsApr 22-30: 0.1% of 14344 checklistsMay 1-7: 0.1% of 8193 checklistsMay 8-14: 0% 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% of 4366 checklistsSep 8-14: 0% of 4648 checklistsSep 15-21: 0% of 4369 checklistsSep 22-30: 0% of 6418 checklistsOct 1-7: 0.1% of 5375 checklistsOct 8-14: 0% of 6213 checklistsOct 15-21: 0% of 5553 checklistsOct 22-31: 0.1% of 8879 checklistsNov 1-7: 0.1% of 6231 checklistsNov 8-14: 0.3% of 5011 checklistsNov 15-21: 0.3% of 4856 checklistsNov 22-30: 0.4% of 6696 checklistsDec 1-7: 0.7% of 4530 checklistsDec 8-14: 0.8% of 4883 checklistsDec 15-21: 1.4% of 5833 checklistsDec 22-31: 1.2% 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. Union ParishBest early January · 55 checklists that week, 2,155 in all29%
  2. Richland ParishBest mid January · 15 checklists that week, 835 in all21%
  3. Pointe Coupee ParishBest early February · 12 checklists that week, 593 in all21%
  4. Jackson ParishBest early March · 20 checklists that week, 481 in all13%
  5. East Carroll ParishBest mid January · 15 checklists that week, 317 in all9.1%
  6. St. Bernard ParishBest mid January · 38 checklists that week, 1,331 in all7.7%

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 February · 40 checklists that week, 1,384 in all12%
  2. Mandeville Lakefront ParkSt. Tammany Parish, best the second week of March · 21 checklists that week, 1,193 in all11%

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

Best time of day

In Louisiana, the Bonaparte's Gull is most often listed on checklists started between 2 and 4 pm (0.7% of those checklists).

0%0.5%1%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: 0.3% of 21115 checklists7 am: 0.4% of 38843 checklists8 am: 0.5% of 36306 checklists9 am: 0.4% of 31934 checklists10 am: 0.5% of 27208 checklists11 am: 0.7% of 20733 checklists12 pm: 0.7% of 18505 checklists1 pm: 0.7% of 17383 checklists2 pm: 0.7% of 17422 checklists3 pm: 0.7% of 17005 checklists4 pm: 0.5% of 17170 checklists5 pm: 0.3% of 12536 checklists6 pm: 0.2% 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
January1.3%1.6%1.3%1.4%
February1.3%1.1%1.2%0.9%
March1.1%1.0%0.7%0.9%
April0.6%0.4%0.1%0.1%
May0.1%0%0%0%
June0%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0%0%0%0%
October0.1%0%0%0.1%
November0.1%0.3%0.3%0.4%
December0.7%0.8%1.4%1.2%

Neighboring states

  • Mississippi: arrives the second week of November, 3 weeks earlier than Louisiana
  • Alabama: arrives mid November, 2 weeks earlier than Louisiana
  • Texas: arrives late November, 1 week earlier than Louisiana
  • Arkansas: arrives mid November, 2 weeks earlier than Louisiana

Common questions

When do Bonaparte's Gulls arrive in Louisiana?
Bonaparte's Gulls are winter birds in Louisiana: they arrive in early December, peak in mid January (1.4% of checklists), and most are gone by early April.
When do Bonaparte's Gulls leave Louisiana?
Most Bonaparte's Gulls have left Louisiana by early April, when reports fall below half their usual rate.
When is the best time to see a Bonaparte's Gull in Louisiana?
The Bonaparte's Gull is reported most often in mid January, on about 1.4% of Louisiana checklists.
Where in Louisiana are Bonaparte's Gulls seen most often?
By county, Union Parish, Richland Parish, and Pointe Coupee Parish have the highest peak reporting rates for the Bonaparte's Gull (counties with at least 200 checklists).