WhenToBird

Camptostoma imberbe · Tyrannidae

When Do Northern Beardless-Tyrannulets Arrive in Arizona?

Adult Northern Beardless-Tyrannulet
Photo: John Rosford, CC BY 4.0 via iNaturalist

Northern Beardless-Tyrannulets arrive in Arizona in mid March, peak in early May (2.7% of checklists), and most are gone by late August.

When to look

First arrivalsMar 15-21mid March
Common byMar 15-21mid March
PeakMay 1-7early May
Most gone byAug 22-31late August

Best: early May. First arrivals mid March; most are gone by late August. Peak: on about 2.7% of Arizona checklists.

  1. Janrare
  2. Febrare
  3. Marcommon
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Sepuncommon
  10. Octrare
  11. Novrare
  12. Decrare

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

0%1%2%3%Jan 1-7: 0.2% of 34758 checklistsJan 8-14: 0.3% of 29835 checklistsJan 15-21: 0.3% of 29279 checklistsJan 22-31: 0.3% of 39716 checklistsFeb 1-7: 0.3% of 27299 checklistsFeb 8-14: 0.3% of 28703 checklistsFeb 15-21: 0.2% of 35357 checklistsFeb 22-28: 0.4% of 29889 checklistsMar 1-7: 0.5% of 29932 checklistsMar 8-14: 0.9% of 32982 checklistsMar 15-21: 1.3% of 34731 checklistsMar 22-31: 1.7% of 50213 checklistsApr 1-7: 2.1% of 35788 checklistsApr 8-14: 2.5% of 38087 checklistsApr 15-21: 2.5% of 41520 checklistsApr 22-30: 2.7% of 55218 checklistsMay 1-7: 2.9% of 39688 checklistsMay 8-14: 2.6% of 39398 checklistsMay 15-21: 2.3% of 29562 checklistsMay 22-31: 2.3% of 36774 checklistsJun 1-7: 2.1% of 21313 checklistsJun 8-14: 1.8% of 19129 checklistsJun 15-21: 1.7% of 17922 checklistsJun 22-30: 1.8% of 21188 checklistsJul 1-7: 1.8% of 17325 checklistsJul 8-14: 2.3% of 16463 checklistsJul 15-21: 2.4% of 18642 checklistsJul 22-31: 2.0% of 31215 checklistsAug 1-7: 2.1% of 28163 checklistsAug 8-14: 1.8% of 31329 checklistsAug 15-21: 1.2% of 23878 checklistsAug 22-31: 1.1% of 28508 checklistsSep 1-7: 0.8% of 20878 checklistsSep 8-14: 0.8% of 19671 checklistsSep 15-21: 0.7% of 19859 checklistsSep 22-30: 0.6% of 25179 checklistsOct 1-7: 0.4% of 19420 checklistsOct 8-14: 0.2% of 21925 checklistsOct 15-21: 0.2% of 20995 checklistsOct 22-31: 0.2% of 29258 checklistsNov 1-7: 0.2% of 21269 checklistsNov 8-14: 0.2% of 22753 checklistsNov 15-21: 0.1% of 21982 checklistsNov 22-30: 0.1% of 29475 checklistsDec 1-7: 0.1% of 20810 checklistsDec 8-14: 0.2% of 22229 checklistsDec 15-21: 0.2% of 25148 checklistsDec 22-31: 0.2% 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. Santa Cruz CountyBest early May · 5233 checklists that week, 162,726 in all12%
  2. Graham CountyBest the second week of July · 143 checklists that week, 9,876 in all7.1%
  3. Greenlee CountyBest mid June · 45 checklists that week, 2,745 in all4.5%
  4. Pima CountyBest mid April · 12689 checklists that week, 437,722 in all2.7%
  5. Cochise CountyBest the second week of May · 7434 checklists that week, 190,093 in all2.0%
  6. Pinal CountyBest the second week of June · 399 checklists that week, 40,036 in all1.6%

Best spots

Share of checklists at the peak
  1. Turkey CreekPima County, best late March · 84 checklists that week, 521 in all55%
  2. Coronado National Forest (Devils Cash Box)Santa Cruz County, best the second week of May · 174 checklists that week, 2,933 in all49%
  3. Coronado National Forest (Weiland Harshaw Storage)Santa Cruz County, best late April · 34 checklists that week, 682 in all49%
  4. Coronado National Forest (Faber Spring)Pima County, best the second week of July · 56 checklists that week, 5,353 in all47%
  5. San Bernardino ValleyCochise County, best late May · 22 checklists that week, 159 in all45%
  6. Negro CanyonSanta Cruz County, best early May · 26 checklists that week, 391 in all43%

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

Best time of day

In Arizona, the Northern Beardless-Tyrannulet is most often listed on checklists started between 5 and 7 am (2.6% 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: 2.6% of 38350 checklists6 am: 2.6% of 118786 checklists7 am: 2.0% of 183415 checklists8 am: 1.5% of 187346 checklists9 am: 1.2% of 151342 checklists10 am: 1.0% of 124522 checklists11 am: 0.8% of 97088 checklists12 pm: 0.7% of 78110 checklists1 pm: 0.6% of 73059 checklists2 pm: 0.5% of 68912 checklists3 pm: 0.4% of 68060 checklists4 pm: 0.4% of 69387 checklists5 pm: 0.3% of 52951 checklists6 pm: 0.3% 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
January0.2%0.3%0.3%0.3%
February0.3%0.3%0.2%0.4%
March0.5%0.9%1.3%1.7%
April2.1%2.5%2.5%2.7%
May2.9%2.6%2.3%2.3%
June2.1%1.8%1.7%1.8%
July1.8%2.3%2.4%2.0%
August2.1%1.8%1.2%1.1%
September0.8%0.8%0.7%0.6%
October0.4%0.2%0.2%0.2%
November0.2%0.2%0.1%0.1%
December0.1%0.2%0.2%0.2%

Common questions

When do Northern Beardless-Tyrannulets arrive in Arizona?
Northern Beardless-Tyrannulets arrive in Arizona in mid March, peak in early May (2.7% of checklists), and most are gone by late August.
When do Northern Beardless-Tyrannulets leave Arizona?
Most Northern Beardless-Tyrannulets have left Arizona by late August, when reports fall below half their usual rate.
When is the best time to see a Northern Beardless-Tyrannulet in Arizona?
The Northern Beardless-Tyrannulet is reported most often in early May, on about 2.7% of Arizona checklists.
Where in Arizona are Northern Beardless-Tyrannulets seen most often?
By county, Santa Cruz County, Graham County, and Greenlee County have the highest peak reporting rates for the Northern Beardless-Tyrannulet (counties with at least 200 checklists).