WhenToBird

Cygnus olor · Anatidae

When Do Mute Swans Arrive in Pennsylvania?

Adult Mute Swan
Photo: Radu Teodoreanu, CC BY 4.0 via iNaturalist

Mute Swans are winter birds in Pennsylvania: the first arrive in mid July, they are common by early August, peak in early March (2.2% of checklists), and most are gone by late May.

When to look

First arrivalsJul 15-21mid July
Common byAug 1-7early August
PeakMar 1-7early March
Most gone byMay 22-31late May

Best: early March. First arrivals mid July; most are gone by late May. Peak: on about 2.2% of Pennsylvania checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprpeak season
  5. Maycommon
  6. Juncommon
  7. Julcommon
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novpeak season
  12. Decpeak season

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

0%1%2%3%Jan 1-7: 1.9% of 47145 checklistsJan 8-14: 2.0% of 35840 checklistsJan 15-21: 1.8% of 35423 checklistsJan 22-31: 1.7% of 49126 checklistsFeb 1-7: 1.6% of 36366 checklistsFeb 8-14: 1.7% of 42248 checklistsFeb 15-21: 1.6% of 55888 checklistsFeb 22-28: 2.2% of 42050 checklistsMar 1-7: 2.2% of 42709 checklistsMar 8-14: 2.1% of 43985 checklistsMar 15-21: 2.2% of 44547 checklistsMar 22-31: 2.0% of 66940 checklistsApr 1-7: 1.8% of 51147 checklistsApr 8-14: 1.9% of 54868 checklistsApr 15-21: 1.9% of 57252 checklistsApr 22-30: 1.7% of 81727 checklistsMay 1-7: 1.5% of 76472 checklistsMay 8-14: 1.5% of 79341 checklistsMay 15-21: 1.4% of 61724 checklistsMay 22-31: 1.5% of 70722 checklistsJun 1-7: 1.1% of 45652 checklistsJun 8-14: 0.8% of 41810 checklistsJun 15-21: 0.8% of 38973 checklistsJun 22-30: 0.9% of 44255 checklistsJul 1-7: 0.8% of 34822 checklistsJul 8-14: 1.0% of 31104 checklistsJul 15-21: 0.9% of 29262 checklistsJul 22-31: 1.2% of 41436 checklistsAug 1-7: 1.2% of 29189 checklistsAug 8-14: 1.3% of 28840 checklistsAug 15-21: 1.2% of 29948 checklistsAug 22-31: 0.9% of 48235 checklistsSep 1-7: 1.1% of 37175 checklistsSep 8-14: 1.0% of 36527 checklistsSep 15-21: 1.1% of 37261 checklistsSep 22-30: 1.2% of 43583 checklistsOct 1-7: 1.4% of 35352 checklistsOct 8-14: 1.5% of 35560 checklistsOct 15-21: 1.3% of 33119 checklistsOct 22-31: 1.5% of 44654 checklistsNov 1-7: 1.7% of 32965 checklistsNov 8-14: 1.9% of 31305 checklistsNov 15-21: 1.7% of 29471 checklistsNov 22-30: 2.0% of 38642 checklistsDec 1-7: 1.8% of 28779 checklistsDec 8-14: 1.7% of 29486 checklistsDec 15-21: 1.2% of 37465 checklistsDec 22-31: 1.5% 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. Philadelphia CountyBest mid March · 1904 checklists that week, 96,503 in all21%
  2. Montour CountyBest mid November · 94 checklists that week, 6,082 in all19%
  3. Lehigh CountyBest mid January · 759 checklists that week, 41,072 in all11%
  4. Wyoming CountyBest the second week of January · 43 checklists that week, 6,156 in all10%
  5. Monroe CountyBest early March · 607 checklists that week, 34,410 in all7.1%
  6. Clarion CountyBest late March · 216 checklists that week, 9,153 in all6.0%

Best spots

Share of checklists at the peak
  1. John Heinz National Wildlife Refuge at TinicumPhiladelphia County, best mid March · 429 checklists that week, 18,127 in all83%
  2. Echo LakeNorthampton County, best the second week of March · 21 checklists that week, 334 in all80%
  3. Illicks Mill ParkNorthampton County, best late September · 25 checklists that week, 802 in all71%
  4. Franklin Delano Roosevelt ParkPhiladelphia County, best mid February · 132 checklists that week, 4,155 in all69%

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

Best time of day

In Pennsylvania, the Mute Swan is most often listed on checklists started between 1 and 3 pm (1.8% of those checklists).

0%0.5%1%1.5%2%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: 1.6% of 92903 checklists7 am: 1.5% of 241233 checklists8 am: 1.5% of 271994 checklists9 am: 1.6% of 236842 checklists10 am: 1.6% of 199508 checklists11 am: 1.7% of 161893 checklists12 pm: 1.7% of 143945 checklists1 pm: 1.8% of 134352 checklists2 pm: 1.7% of 129692 checklists3 pm: 1.6% of 126132 checklists4 pm: 1.4% of 115055 checklists5 pm: 1.2% of 90719 checklists6 pm: 1.0% of 67534 checklists7 pm: 0.7% 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
January1.9%2.0%1.8%1.7%
February1.6%1.7%1.6%2.2%
March2.2%2.1%2.2%2.0%
April1.8%1.9%1.9%1.7%
May1.5%1.5%1.4%1.5%
June1.1%0.8%0.8%0.9%
July0.8%1.0%0.9%1.2%
August1.2%1.3%1.2%0.9%
September1.1%1.0%1.1%1.2%
October1.4%1.5%1.3%1.5%
November1.7%1.9%1.7%2.0%
December1.8%1.7%1.2%1.5%

Neighboring states

  • Delaware: arrives early March, 18 weeks earlier than Pennsylvania
  • New Jersey: year-round, peaks the second week of October
  • New York: year-round, peaks the second week of January
  • Connecticut: year-round, peaks late March

Common questions

When do Mute Swans arrive in Pennsylvania?
Mute Swans are winter birds in Pennsylvania: the first arrive in mid July, they are common by early August, peak in early March (2.2% of checklists), and most are gone by late May.
When do Mute Swans leave Pennsylvania?
Most Mute Swans have left Pennsylvania by late May, when reports fall below half their usual rate. Stragglers are still reported until the second week of June.
When is the best time to see a Mute Swan in Pennsylvania?
The Mute Swan is reported most often in early March, on about 2.2% of Pennsylvania checklists.
Where in Pennsylvania are Mute Swans seen most often?
By county, Philadelphia County, Montour County, and Lehigh County have the highest peak reporting rates for the Mute Swan (counties with at least 200 checklists).