WhenToBird

Contopus cooperi · Tyrannidae

When Do Olive-sided Flycatchers Arrive in Alaska?

Adult Olive-sided Flycatcher
Photo: Brooke J., CC BY 4.0 via iNaturalist

Olive-sided Flycatchers arrive in Alaska in the second week of May, peak in the second week of June (2.2% of checklists), and most are gone by mid August.

When to look

First arrivalsMay 8-14the second week of May
Common byMay 8-14the second week of May
PeakJun 8-14the second week of June
Most gone byAug 15-21mid August

Best: the second week of June. First arrivals the second week of May; most are gone by mid August. Peak: on about 2.2% of Alaska checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprnot usually seen
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Augcommon
  9. Seprare
  10. Octnot usually seen
  11. Novnot usually seen
  12. Decnot usually seen

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

0%1%2%3%Jan 1-7: 0% of 3788 checklistsJan 8-14: 0% of 2852 checklistsJan 15-21: 0% of 2810 checklistsJan 22-31: 0% of 3629 checklistsFeb 1-7: 0% of 2519 checklistsFeb 8-14: 0% of 2927 checklistsFeb 15-21: 0% of 3743 checklistsFeb 22-28: 0% of 2846 checklistsMar 1-7: 0% of 2904 checklistsMar 8-14: 0% of 3073 checklistsMar 15-21: 0% of 3359 checklistsMar 22-31: 0% of 5855 checklistsApr 1-7: 0% of 4329 checklistsApr 8-14: 0% of 4949 checklistsApr 15-21: 0% of 7114 checklistsApr 22-30: 0.1% of 10916 checklistsMay 1-7: 0.2% of 11827 checklistsMay 8-14: 0.6% of 14115 checklistsMay 15-21: 1.3% of 12152 checklistsMay 22-31: 1.8% of 19919 checklistsJun 1-7: 1.9% of 15816 checklistsJun 8-14: 2.5% of 17194 checklistsJun 15-21: 2.1% of 15943 checklistsJun 22-30: 1.4% of 16192 checklistsJul 1-7: 0.8% of 9815 checklistsJul 8-14: 0.9% of 8263 checklistsJul 15-21: 0.6% of 7081 checklistsJul 22-31: 1.2% of 9434 checklistsAug 1-7: 1.0% of 6380 checklistsAug 8-14: 1.0% of 6258 checklistsAug 15-21: 0.7% of 6114 checklistsAug 22-31: 0.3% of 8189 checklistsSep 1-7: 0.1% of 5848 checklistsSep 8-14: 0.1% of 4853 checklistsSep 15-21: 0.1% of 4415 checklistsSep 22-30: 0.1% of 5086 checklistsOct 1-7: 0% of 3576 checklistsOct 8-14: 0% of 4212 checklistsOct 15-21: 0% of 3339 checklistsOct 22-31: 0.1% of 4169 checklistsNov 1-7: 0% of 2844 checklistsNov 8-14: 0% of 2753 checklistsNov 15-21: 0% of 2291 checklistsNov 22-30: 0% of 3066 checklistsDec 1-7: 0% of 2199 checklistsDec 8-14: 0% of 2472 checklistsDec 15-21: 0% of 3071 checklistsDec 22-31: 0% of 3442 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 Alaska 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 Alaska

Best counties

Share of checklists at the peak
  1. Yukon-Koyukuk Census AreaBest the second week of July · 158 checklists that week, 2,835 in all14%
  2. Northwest Arctic BoroughBest early August · 72 checklists that week, 1,386 in all8.7%
  3. Southeast Fairbanks Census AreaBest late May · 227 checklists that week, 3,009 in all8.3%
  4. Fairbanks North Star BoroughBest mid June · 1042 checklists that week, 23,771 in all4.8%
  5. Matanuska-Susitna BoroughBest the second week of June · 1099 checklists that week, 23,028 in all4.5%
  6. Copper River Census AreaBest early June · 209 checklists that week, 3,467 in all4.2%

Best spots

Share of checklists at the peak
  1. Viapan LakeKenai Peninsula Borough, best late May · 35 checklists that week, 153 in all24%
  2. Beluga LakeKenai Peninsula Borough, best late June · 20 checklists that week, 557 in all19%
  3. Otter LakeAnchorage Municipality, best late May · 33 checklists that week, 143 in all19%
  4. Hillside ParkAnchorage Municipality, best late May · 41 checklists that week, 338 in all14%

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

Best time of day

In Alaska, the Olive-sided Flycatcher is most often listed on checklists started between 6 and 8 am (1.6% of those checklists).

0%0.5%1%1.5%2%12 am: too few checklists (549) to judge1 am: too few checklists (365) to judge2 am: too few checklists (291) to judge3 am: too few checklists (624) to judge4 am: too few checklists (1241) to judge5 am: too few checklists (3532) to judge6 am: 1.8% of 9751 checklists7 am: 1.4% of 17236 checklists8 am: 1.1% of 24936 checklists9 am: 1.0% of 30139 checklists10 am: 0.7% of 30866 checklists11 am: 0.7% of 28207 checklists12 pm: 0.6% of 25650 checklists1 pm: 0.6% of 24144 checklists2 pm: 0.5% of 23323 checklists3 pm: 0.5% of 20763 checklists4 pm: 0.5% of 18245 checklists5 pm: 0.6% of 14895 checklists6 pm: 0.5% of 11707 checklists7 pm: 0.5% of 9365 checklists8 pm: 0.5% of 6934 checklists9 pm: too few checklists (4176) to judge10 pm: too few checklists (2050) to judge11 pm: too few checklists (952) 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%0%0%0%
February0%0%0%0%
March0%0%0%0%
April0%0%0%0.1%
May0.2%0.6%1.3%1.8%
June1.9%2.5%2.1%1.4%
July0.8%0.9%0.6%1.2%
August1.0%1.0%0.7%0.3%
September0.1%0.1%0.1%0.1%
October0%0%0%0.1%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • Washington: arrives early May, 1 week earlier than Alaska
  • Oregon: arrives early May, 1 week earlier than Alaska
  • Idaho: arrives mid May, 1 week later than Alaska
  • Montana: arrives late May, 2 weeks later than Alaska

Common questions

When do Olive-sided Flycatchers arrive in Alaska?
Olive-sided Flycatchers arrive in Alaska in the second week of May, peak in the second week of June (2.2% of checklists), and most are gone by mid August.
When do Olive-sided Flycatchers leave Alaska?
Most Olive-sided Flycatchers have left Alaska by mid August, when reports fall below half their usual rate.
When is the best time to see a Olive-sided Flycatcher in Alaska?
The Olive-sided Flycatcher is reported most often in the second week of June, on about 2.2% of Alaska checklists.
Where in Alaska are Olive-sided Flycatchers seen most often?
By county, Yukon-Koyukuk Census Area, Northwest Arctic Borough, and Southeast Fairbanks Census Area have the highest peak reporting rates for the Olive-sided Flycatcher (counties with at least 200 checklists).