WhenToBird

Chroicocephalus philadelphia · Laridae

When Do Bonaparte's Gulls Arrive in Oregon?

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

Bonaparte's Gulls mostly pass through Oregon: they arrive in the second week of July, peak in early November (2.9% of checklists), and most are gone by the second week of December.

When to look

First arrivalsJul 8-14the second week of July
Common byJul 8-14the second week of July
PeakNov 1-7early November
Most gone byDec 8-14the second week of December

Best: early November. First arrivals the second week of July; most are gone by the second week of December. Peak: on about 2.9% of Oregon checklists.

  1. Janrare
  2. Febnot usually seen
  3. Marrare
  4. Apruncommon
  5. Mayuncommon
  6. Jununcommon
  7. Juluncommon
  8. Auguncommon
  9. Sepuncommon
  10. Octpeak season
  11. Novpeak season
  12. Decuncommon

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

0%1%2%3%4%Jan 1-7: 0.1% of 34973 checklistsJan 8-14: 0.1% of 26807 checklistsJan 15-21: 0.1% of 26567 checklistsJan 22-31: 0.1% of 36019 checklistsFeb 1-7: 0.1% of 24020 checklistsFeb 8-14: 0.1% of 25765 checklistsFeb 15-21: 0.1% of 31019 checklistsFeb 22-28: 0.1% of 24582 checklistsMar 1-7: 0.1% of 24834 checklistsMar 8-14: 0.1% of 24642 checklistsMar 15-21: 0.1% of 27420 checklistsMar 22-31: 0.1% of 39913 checklistsApr 1-7: 0.3% of 28817 checklistsApr 8-14: 0.3% of 31221 checklistsApr 15-21: 0.5% of 34402 checklistsApr 22-30: 0.8% of 47144 checklistsMay 1-7: 1.1% of 37716 checklistsMay 8-14: 0.8% of 39651 checklistsMay 15-21: 1.0% of 37496 checklistsMay 22-31: 0.6% of 56967 checklistsJun 1-7: 0.4% of 35893 checklistsJun 8-14: 0.4% of 31880 checklistsJun 15-21: 0.2% of 30942 checklistsJun 22-30: 0.1% of 38478 checklistsJul 1-7: 0.2% of 27409 checklistsJul 8-14: 0.2% of 25161 checklistsJul 15-21: 0.4% of 25473 checklistsJul 22-31: 0.5% of 33920 checklistsAug 1-7: 0.5% of 24310 checklistsAug 8-14: 0.5% of 23675 checklistsAug 15-21: 0.6% of 23623 checklistsAug 22-31: 0.5% of 33762 checklistsSep 1-7: 0.5% of 25120 checklistsSep 8-14: 0.4% of 24458 checklistsSep 15-21: 0.4% of 25528 checklistsSep 22-30: 0.3% of 31631 checklistsOct 1-7: 0.3% of 25498 checklistsOct 8-14: 0.5% of 25161 checklistsOct 15-21: 1.0% of 23701 checklistsOct 22-31: 2.9% of 30996 checklistsNov 1-7: 3.2% of 21089 checklistsNov 8-14: 2.7% of 21880 checklistsNov 15-21: 1.8% of 21501 checklistsNov 22-30: 1.0% of 28930 checklistsDec 1-7: 0.3% of 19807 checklistsDec 8-14: 0.3% of 21022 checklistsDec 15-21: 0.2% of 24817 checklistsDec 22-31: 0.2% of 37592 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 Oregon 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 Oregon

Best counties

Share of checklists at the peak
  1. Sherman CountyBest the second week of November · 238 checklists that week, 4,629 in all38%
  2. Klamath CountyBest the second week of November · 213 checklists that week, 26,875 in all20%
  3. Umatilla CountyBest the second week of November · 287 checklists that week, 17,651 in all14%
  4. Wasco CountyBest early November · 142 checklists that week, 13,127 in all13%
  5. Hood River CountyBest late October · 229 checklists that week, 9,695 in all9.2%
  6. Union CountyBest early November · 467 checklists that week, 33,301 in all7.3%

Best spots

Share of checklists at the peak
  1. Hellroaring CanyonSherman County, best the second week of November · 92 checklists that week, 344 in all95%
  2. Spillway ParkUmatilla County, best the second week of November · 25 checklists that week, 340 in all92%
  3. Wickiup ReservoirDeschutes County, best late October · 31 checklists that week, 143 in all67%
  4. Putnams PointKlamath County, best early November · 27 checklists that week, 752 in all63%
  5. Bradford IslandMultnomah County, best the second week of November · 30 checklists that week, 241 in all45%

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

Best time of day

In Oregon, the Bonaparte's Gull is most often listed on checklists started between 11 am and 1 pm (0.6% of those checklists).

0%0.5%1%12 am: too few checklists (1505) to judge1 am: too few checklists (675) to judge2 am: too few checklists (626) to judge3 am: too few checklists (1641) to judge4 am: too few checklists (3696) to judge5 am: too few checklists (14524) to judge6 am: 0.5% of 50677 checklists7 am: 0.5% of 125347 checklists8 am: 0.5% of 163668 checklists9 am: 0.6% of 160351 checklists10 am: 0.6% of 148940 checklists11 am: 0.6% of 124743 checklists12 pm: 0.6% of 112537 checklists1 pm: 0.6% of 98999 checklists2 pm: 0.6% of 94690 checklists3 pm: 0.6% of 87923 checklists4 pm: 0.5% of 75235 checklists5 pm: 0.4% of 54504 checklists6 pm: 0.4% of 40469 checklists7 pm: 0.3% of 33675 checklists8 pm: too few checklists (18715) to judge9 pm: too few checklists (5839) to judge10 pm: too few checklists (2704) to judge11 pm: too few checklists (1549) 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%0.1%0.1%0.1%
February0.1%0.1%0.1%0.1%
March0.1%0.1%0.1%0.1%
April0.3%0.3%0.5%0.8%
May1.1%0.8%1.0%0.6%
June0.4%0.4%0.2%0.1%
July0.2%0.2%0.4%0.5%
August0.5%0.5%0.6%0.5%
September0.5%0.4%0.4%0.3%
October0.3%0.5%1.0%2.9%
November3.2%2.7%1.8%1.0%
December0.3%0.3%0.2%0.2%

Neighboring states

  • Washington: arrives mid July, 1 week later than Oregon
  • Idaho: arrives early August, 3 weeks later than Oregon
  • Nevada: arrives early July, 1 week earlier than Oregon
  • California: arrives mid October, 13 weeks later than Oregon

Common questions

When do Bonaparte's Gulls arrive in Oregon?
Bonaparte's Gulls mostly pass through Oregon: they arrive in the second week of July, peak in early November (2.9% of checklists), and most are gone by the second week of December.
When do Bonaparte's Gulls leave Oregon?
Most Bonaparte's Gulls have left Oregon by the second week of December, when reports fall below half their usual rate.
When is the best time to see a Bonaparte's Gull in Oregon?
The Bonaparte's Gull is reported most often in early November, on about 2.9% of Oregon checklists.
Where in Oregon are Bonaparte's Gulls seen most often?
By county, Sherman County, Klamath County, and Umatilla County have the highest peak reporting rates for the Bonaparte's Gull (counties with at least 200 checklists).