WhenToBird

Spizelloides arborea · Passerellidae

When Do American Tree Sparrows Arrive in Pennsylvania?

Adult American Tree Sparrow
Photo: Michael, CC BY 4.0 via iNaturalist

American Tree Sparrows are winter birds in Pennsylvania: the first arrive in the second week of November, they are common by mid November, peak in early February (5.8% of checklists), and most are gone by mid March.

When to look

First arrivalsNov 8-14the second week of November
Common byNov 15-21mid November
PeakFeb 1-7early February
Most gone byMar 15-21mid March

Best: early February. First arrivals the second week of November; most are gone by mid March. Peak: on about 5.8% of Pennsylvania checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Apruncommon
  5. Maynot usually seen
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octrare
  11. Novcommon
  12. Decpeak season

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

0%2%4%6%8%Jan 1-7: 5.3% of 47145 checklistsJan 8-14: 5.6% of 35840 checklistsJan 15-21: 5.6% of 35423 checklistsJan 22-31: 6.1% of 49126 checklistsFeb 1-7: 5.6% of 36366 checklistsFeb 8-14: 5.8% of 42248 checklistsFeb 15-21: 4.5% of 55888 checklistsFeb 22-28: 4.3% of 42050 checklistsMar 1-7: 4.0% of 42709 checklistsMar 8-14: 3.6% of 43985 checklistsMar 15-21: 2.7% of 44547 checklistsMar 22-31: 1.8% of 66940 checklistsApr 1-7: 1.3% of 51147 checklistsApr 8-14: 0.7% of 54868 checklistsApr 15-21: 0.2% of 57252 checklistsApr 22-30: 0.1% of 81727 checklistsMay 1-7: 0.1% of 76472 checklistsMay 8-14: 0.1% of 79341 checklistsMay 15-21: 0% of 61724 checklistsMay 22-31: 0.1% of 70722 checklistsJun 1-7: 0% of 45652 checklistsJun 8-14: 0% of 41810 checklistsJun 15-21: 0% of 38973 checklistsJun 22-30: 0% of 44255 checklistsJul 1-7: 0% of 34822 checklistsJul 8-14: 0% of 31104 checklistsJul 15-21: 0% of 29262 checklistsJul 22-31: 0% of 41436 checklistsAug 1-7: 0% of 29189 checklistsAug 8-14: 0% of 28840 checklistsAug 15-21: 0% of 29948 checklistsAug 22-31: 0% of 48235 checklistsSep 1-7: 0% of 37175 checklistsSep 8-14: 0% of 36527 checklistsSep 15-21: 0% of 37261 checklistsSep 22-30: 0.1% of 43583 checklistsOct 1-7: 0.1% of 35352 checklistsOct 8-14: 0.1% of 35560 checklistsOct 15-21: 0.1% of 33119 checklistsOct 22-31: 0.2% of 44654 checklistsNov 1-7: 0.6% of 32965 checklistsNov 8-14: 1.4% of 31305 checklistsNov 15-21: 2.7% of 29471 checklistsNov 22-30: 3.7% of 38642 checklistsDec 1-7: 4.4% of 28779 checklistsDec 8-14: 4.9% of 29486 checklistsDec 15-21: 5.6% of 37465 checklistsDec 22-31: 5.7% of 50651 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 Pennsylvania 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 Pennsylvania

Best counties

Share of checklists at the peak
  1. Jefferson CountyBest mid January · 69 checklists that week, 5,956 in all42%
  2. Carbon CountyBest late January · 443 checklists that week, 16,269 in all33%
  3. Wayne CountyBest late January · 149 checklists that week, 10,444 in all29%
  4. Venango CountyBest late January · 38 checklists that week, 2,831 in all24%
  5. Elk CountyBest late January · 117 checklists that week, 6,751 in all24%
  6. Warren CountyBest early February · 63 checklists that week, 5,449 in all23%

Best spots

Share of checklists at the peak
  1. Sgl 227Schuylkill County, best late December · 21 checklists that week, 442 in all78%
  2. Hunt LakeSusquehanna County, best mid January · 27 checklists that week, 1,188 in all74%
  3. Hall PondLycoming County, best the second week of December · 29 checklists that week, 1,740 in all71%
  4. Shenango River LakeMercer County, best mid February · 29 checklists that week, 1,320 in all69%

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

Best time of day

In Pennsylvania, the American Tree Sparrow is most often listed on checklists started between 8 and 10 am (2.1% of those checklists).

0%1%2%3%12 am: too few checklists (1558) to judge1 am: too few checklists (1136) to judge2 am: too few checklists (839) to judge3 am: too few checklists (842) to judge4 am: too few checklists (2550) to judge5 am: too few checklists (18294) to judge6 am: 0.7% of 92903 checklists7 am: 1.9% of 241233 checklists8 am: 2.1% of 271994 checklists9 am: 2.1% of 236842 checklists10 am: 2.0% of 199508 checklists11 am: 2.0% of 161893 checklists12 pm: 1.9% of 143945 checklists1 pm: 1.9% of 134352 checklists2 pm: 1.9% of 129692 checklists3 pm: 1.8% of 126132 checklists4 pm: 1.5% of 115055 checklists5 pm: 0.7% of 90719 checklists6 pm: 0.4% of 67534 checklists7 pm: 0.1% of 43004 checklists8 pm: too few checklists (13966) to judge9 pm: too few checklists (3913) to judge10 pm: too few checklists (1989) to judge11 pm: too few checklists (1146) 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
January5.3%5.6%5.6%6.1%
February5.6%5.8%4.5%4.3%
March4.0%3.6%2.7%1.8%
April1.3%0.7%0.2%0.1%
May0.1%0.1%0%0.1%
June0%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0%0%0%0.1%
October0.1%0.1%0.1%0.2%
November0.6%1.4%2.7%3.7%
December4.4%4.9%5.6%5.7%

Neighboring states

  • Maryland: arrives mid November, 1 week later than Pennsylvania
  • District of Columbia: arrives mid January, 9 weeks later than Pennsylvania
  • New Jersey: arrives the second week of November, in the same week than Pennsylvania
  • New York: arrives late October, 2 weeks earlier than Pennsylvania

Common questions

When do American Tree Sparrows arrive in Pennsylvania?
American Tree Sparrows are winter birds in Pennsylvania: the first arrive in the second week of November, they are common by mid November, peak in early February (5.8% of checklists), and most are gone by mid March.
When do American Tree Sparrows leave Pennsylvania?
Most American Tree Sparrows have left Pennsylvania by mid March, when reports fall below half their usual rate. Stragglers are still reported until early April.
When is the best time to see a American Tree Sparrow in Pennsylvania?
The American Tree Sparrow is reported most often in early February, on about 5.8% of Pennsylvania checklists.
Where in Pennsylvania are American Tree Sparrows seen most often?
By county, Jefferson County, Carbon County, and Wayne County have the highest peak reporting rates for the American Tree Sparrow (counties with at least 200 checklists).