WhenToBird

Podiceps auritus · Podicipedidae

When Do Horned Grebes Arrive in Pennsylvania?

Adult Horned Grebe
Photo: Kalvin Chan, CC BY 4.0 via iNaturalist

Horned Grebes are winter birds in Pennsylvania: they arrive in mid February, peak in late March (4.5% of checklists), and most are gone by late April.

When to look

First arrivalsFeb 15-21mid February
Common byFeb 15-21mid February
PeakMar 22-31late March
Most gone byApr 22-30late April

Best: late March. First arrivals mid February; most are gone by late April. Peak: on about 4.5% of Pennsylvania checklists.

  1. Janrare
  2. Febuncommon
  3. Marpeak season
  4. Aprpeak season
  5. Mayrare
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octrare
  11. Novuncommon
  12. Decuncommon

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

0%2%4%6%Jan 1-7: 0.4% of 47145 checklistsJan 8-14: 0.3% of 35840 checklistsJan 15-21: 0.6% of 35423 checklistsJan 22-31: 0.3% of 49126 checklistsFeb 1-7: 0.4% of 36366 checklistsFeb 8-14: 0.4% of 42248 checklistsFeb 15-21: 0.5% of 55888 checklistsFeb 22-28: 1.3% of 42050 checklistsMar 1-7: 1.9% of 42709 checklistsMar 8-14: 2.6% of 43985 checklistsMar 15-21: 3.9% of 44547 checklistsMar 22-31: 4.6% of 66940 checklistsApr 1-7: 5.0% of 51147 checklistsApr 8-14: 3.4% of 54868 checklistsApr 15-21: 2.2% of 57252 checklistsApr 22-30: 0.9% of 81727 checklistsMay 1-7: 0.4% of 76472 checklistsMay 8-14: 0.2% of 79341 checklistsMay 15-21: 0.1% of 61724 checklistsMay 22-31: 0.1% of 70722 checklistsJun 1-7: 0.1% of 45652 checklistsJun 8-14: 0.1% of 41810 checklistsJun 15-21: 0.1% of 38973 checklistsJun 22-30: 0% of 44255 checklistsJul 1-7: 0.1% of 34822 checklistsJul 8-14: 0% of 31104 checklistsJul 15-21: 0.1% of 29262 checklistsJul 22-31: 0.1% of 41436 checklistsAug 1-7: 0.1% of 29189 checklistsAug 8-14: 0.1% of 28840 checklistsAug 15-21: 0.1% of 29948 checklistsAug 22-31: 0.1% of 48235 checklistsSep 1-7: 0.1% of 37175 checklistsSep 8-14: 0.1% of 36527 checklistsSep 15-21: 0.1% 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: 0.2% of 33119 checklistsOct 22-31: 0.7% of 44654 checklistsNov 1-7: 0.8% of 32965 checklistsNov 8-14: 1.1% of 31305 checklistsNov 15-21: 1.3% of 29471 checklistsNov 22-30: 1.4% of 38642 checklistsDec 1-7: 1.5% of 28779 checklistsDec 8-14: 0.7% of 29486 checklistsDec 15-21: 0.6% of 37465 checklistsDec 22-31: 0.5% 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. Montour CountyBest the second week of April · 198 checklists that week, 6,082 in all25%
  2. Erie CountyBest late November · 1043 checklists that week, 49,012 in all22%
  3. Carbon CountyBest late March · 587 checklists that week, 16,269 in all17%
  4. Venango CountyBest late March · 65 checklists that week, 2,831 in all16%
  5. Lycoming CountyBest early April · 706 checklists that week, 29,685 in all15%
  6. Butler CountyBest late March · 1801 checklists that week, 46,093 in all15%

Best spots

Share of checklists at the peak
  1. Hall PondLycoming County, best the second week of April · 77 checklists that week, 1,740 in all84%
  2. Kahle LakeClarion County, best early April · 21 checklists that week, 273 in all77%
  3. Thompson BayErie County, best late November · 25 checklists that week, 714 in all76%
  4. Ridge PondErie County, best the second week of November · 77 checklists that week, 1,112 in all74%
  5. Niagara Pond (Gull Point)Erie County, best early April · 23 checklists that week, 521 in all70%
  6. Pleasant Valley BeachButler County, best late March · 140 checklists that week, 2,177 in all63%

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

Best time of day

In Pennsylvania, the Horned Grebe is most often listed on checklists started between 2 and 4 pm (1.1% of those checklists).

0%0.5%1%1.5%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: 0.8% of 241233 checklists8 am: 0.7% of 271994 checklists9 am: 0.8% of 236842 checklists10 am: 0.9% of 199508 checklists11 am: 1.0% of 161893 checklists12 pm: 1.1% of 143945 checklists1 pm: 1.1% of 134352 checklists2 pm: 1.1% of 129692 checklists3 pm: 1.1% of 126132 checklists4 pm: 1.0% of 115055 checklists5 pm: 1.0% of 90719 checklists6 pm: 0.9% of 67534 checklists7 pm: 0.4% 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
January0.4%0.3%0.6%0.3%
February0.4%0.4%0.5%1.3%
March1.9%2.6%3.9%4.6%
April5.0%3.4%2.2%0.9%
May0.4%0.2%0.1%0.1%
June0.1%0.1%0.1%0%
July0.1%0%0.1%0.1%
August0.1%0.1%0.1%0.1%
September0.1%0.1%0.1%0.1%
October0.1%0.1%0.2%0.7%
November0.8%1.1%1.3%1.4%
December1.5%0.7%0.6%0.5%

Neighboring states

  • Maryland: arrives early November, 14 weeks earlier than Pennsylvania
  • District of Columbia: arrives early November, 14 weeks earlier than Pennsylvania
  • Delaware: arrives late November, 11 weeks earlier than Pennsylvania
  • New Jersey: arrives the second week of November, 13 weeks earlier than Pennsylvania

Common questions

When do Horned Grebes arrive in Pennsylvania?
Horned Grebes are winter birds in Pennsylvania: they arrive in mid February, peak in late March (4.5% of checklists), and most are gone by late April.
When do Horned Grebes leave Pennsylvania?
Most Horned Grebes have left Pennsylvania by late April, when reports fall below half their usual rate.
When is the best time to see a Horned Grebe in Pennsylvania?
The Horned Grebe is reported most often in late March, on about 4.5% of Pennsylvania checklists.
Where in Pennsylvania are Horned Grebes seen most often?
By county, Montour County, Erie County, and Carbon County have the highest peak reporting rates for the Horned Grebe (counties with at least 200 checklists).