WhenToBird

Myiodynastes luteiventris · Tyrannidae

When Do Sulphur-bellied Flycatchers Arrive in Arizona?

Adult Sulphur-bellied Flycatcher
Photo: Juan Carlos Pérez Magaña, CC BY-SA 4.0 via iNaturalist

Sulphur-bellied Flycatchers reach Arizona in the second week of May, are common by mid May, peak in early August (5.0% of checklists), and most are gone by late August.

When to look

First arrivalsMay 8-14the second week of May
Common byMay 15-21mid May
PeakAug 1-7early August
Most gone byAug 22-31late August

Best: early August. First arrivals the second week of May; most are gone by late August. Peak: on about 5.0% of Arizona checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprnot usually seen
  5. Maycommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Sepuncommon
  10. Octnot usually seen
  11. Novnot usually seen
  12. Decnot usually seen

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

0%2%4%6%Jan 1-7: 0% of 34758 checklistsJan 8-14: 0% of 29835 checklistsJan 15-21: 0% of 29279 checklistsJan 22-31: 0% of 39716 checklistsFeb 1-7: 0% of 27299 checklistsFeb 8-14: 0% of 28703 checklistsFeb 15-21: 0% of 35357 checklistsFeb 22-28: 0% of 29889 checklistsMar 1-7: 0% of 29932 checklistsMar 8-14: 0% of 32982 checklistsMar 15-21: 0% of 34731 checklistsMar 22-31: 0% of 50213 checklistsApr 1-7: 0% of 35788 checklistsApr 8-14: 0% of 38087 checklistsApr 15-21: 0% of 41520 checklistsApr 22-30: 0% of 55218 checklistsMay 1-7: 0.2% of 39688 checklistsMay 8-14: 0.8% of 39398 checklistsMay 15-21: 2.6% of 29562 checklistsMay 22-31: 3.4% of 36774 checklistsJun 1-7: 3.4% of 21313 checklistsJun 8-14: 3.0% of 19129 checklistsJun 15-21: 3.4% of 17922 checklistsJun 22-30: 3.1% of 21188 checklistsJul 1-7: 3.6% of 17325 checklistsJul 8-14: 3.5% of 16463 checklistsJul 15-21: 3.7% of 18642 checklistsJul 22-31: 4.3% of 31215 checklistsAug 1-7: 5.6% of 28163 checklistsAug 8-14: 5.2% of 31329 checklistsAug 15-21: 4.0% of 23878 checklistsAug 22-31: 2.7% of 28508 checklistsSep 1-7: 0.9% of 20878 checklistsSep 8-14: 0.2% of 19671 checklistsSep 15-21: 0.1% of 19859 checklistsSep 22-30: 0.1% of 25179 checklistsOct 1-7: 0.1% of 19420 checklistsOct 8-14: 0% of 21925 checklistsOct 15-21: 0% of 20995 checklistsOct 22-31: 0% of 29258 checklistsNov 1-7: 0% of 21269 checklistsNov 8-14: 0% of 22753 checklistsNov 15-21: 0% of 21982 checklistsNov 22-30: 0% of 29475 checklistsDec 1-7: 0% of 20810 checklistsDec 8-14: 0% of 22229 checklistsDec 15-21: 0% of 25148 checklistsDec 22-31: 0% of 39567 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 Arizona 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 Arizona

Best counties

Share of checklists at the peak
  1. Cochise CountyBest early August · 8010 checklists that week, 190,093 in all13%
  2. Santa Cruz CountyBest the second week of August · 5301 checklists that week, 162,726 in all10%
  3. Pima CountyBest the second week of June · 5106 checklists that week, 437,722 in all1.8%
  4. Greenlee CountyBest late May · 115 checklists that week, 2,745 in all1.2%
  5. Graham CountyBest early August · 238 checklists that week, 9,876 in all0.9%
  6. Gila CountyBest early August · 295 checklists that week, 14,834 in all0.5%

Best spots

Share of checklists at the peak
  1. Smithsonian Institute Astrophysical Observatory Experimental Research AreaSanta Cruz County, best the second week of July · 42 checklists that week, 2,714 in all83%
  2. Miller Peak WildernessCochise County, best early August · 119 checklists that week, 1,953 in all81%
  3. Ramsey Canyon PreserveCochise County, best the second week of July · 110 checklists that week, 7,343 in all81%

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

Best time of day

In Arizona, the Sulphur-bellied Flycatcher is most often listed on checklists started between 5 and 7 am (1.9% of those checklists).

0%1%2%3%12 am: too few checklists (488) to judge1 am: too few checklists (503) to judge2 am: too few checklists (489) to judge3 am: too few checklists (735) to judge4 am: too few checklists (4115) to judge5 am: 2.4% of 38350 checklists6 am: 1.7% of 118786 checklists7 am: 1.2% of 183415 checklists8 am: 1.2% of 187346 checklists9 am: 1.0% of 151342 checklists10 am: 0.8% of 124522 checklists11 am: 0.7% of 97088 checklists12 pm: 0.6% of 78110 checklists1 pm: 0.6% of 73059 checklists2 pm: 0.6% of 68912 checklists3 pm: 0.6% of 68060 checklists4 pm: 0.5% of 69387 checklists5 pm: 0.7% of 52951 checklists6 pm: 0.8% of 31061 checklists7 pm: too few checklists (16076) to judge8 pm: too few checklists (5352) to judge9 pm: too few checklists (2369) to judge10 pm: too few checklists (1100) to judge11 pm: too few checklists (604) 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%
May0.2%0.8%2.6%3.4%
June3.4%3.0%3.4%3.1%
July3.6%3.5%3.7%4.3%
August5.6%5.2%4.0%2.7%
September0.9%0.2%0.1%0.1%
October0.1%0%0%0%
November0%0%0%0%
December0%0%0%0%

Common questions

When do Sulphur-bellied Flycatchers arrive in Arizona?
Sulphur-bellied Flycatchers reach Arizona in the second week of May, are common by mid May, peak in early August (5.0% of checklists), and most are gone by late August.
When do Sulphur-bellied Flycatchers leave Arizona?
Most Sulphur-bellied Flycatchers have left Arizona by late August, when reports fall below half their usual rate. Stragglers are still reported until early September.
When is the best time to see a Sulphur-bellied Flycatcher in Arizona?
The Sulphur-bellied Flycatcher is reported most often in early August, on about 5.0% of Arizona checklists.
Where in Arizona are Sulphur-bellied Flycatchers seen most often?
By county, Cochise County, Santa Cruz County, and Pima County have the highest peak reporting rates for the Sulphur-bellied Flycatcher (counties with at least 200 checklists).