Buffleheads are winter birds in Pennsylvania: they arrive in late October, peak in late March (11% of checklists), and most are gone by mid April.
When to look
First arrivalsOct 22-31late October
Common byOct 22-31late October
PeakMar 22-31late March
Most gone byApr 15-21mid April
Best: late March. First arrivals late October; most are gone by mid April. Peak: on about 11% of Pennsylvania checklists.
Jancommon
Febcommon
Marpeak season
Aprpeak season
Mayrare
Junnot usually seen
Julnot usually seen
Augnot usually seen
Sepnot usually seen
Octuncommon
Novpeak season
Deccommon
Darker months: more checklists report it. Outlined: peak month.
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
0%few checklistsno data
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.
Montour CountyBest the second week of November · 93 checklists that week, 6,082 in all43%
Crawford CountyBest late March · 1080 checklists that week, 23,552 in all36%
Erie CountyBest mid March · 1035 checklists that week, 49,012 in all32%
Wayne CountyBest early April · 229 checklists that week, 10,444 in all29%
Carbon CountyBest mid March · 330 checklists that week, 16,269 in all28%
Butler CountyBest late March · 1801 checklists that week, 46,093 in all28%
Best spots
Share of checklists at the peak
Misery BayErie County, best late March · 21 checklists that week, 290 in all100%
Weatherstone Open SpaceChester County, best late November · 32 checklists that week, 725 in all99%
Hall PondLycoming County, best the second week of April · 77 checklists that week, 1,740 in all96%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Pennsylvania, the Bufflehead is most often listed on checklists started between 1 and 3 pm (4.6% of those checklists).
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
Month
Days 1-7
8-14
15-21
22-end
January
5.2%
4.7%
4.5%
4.6%
February
4.7%
4.5%
4.4%
7.5%
March
9.0%
9.7%
11%
11%
April
9.9%
7.2%
4.8%
2.0%
May
1.2%
0.7%
0.4%
0.2%
June
0.2%
0.1%
0.1%
0.1%
July
0.1%
0.1%
0.1%
0.1%
August
0.1%
0.1%
0.1%
0.1%
September
0.1%
0.1%
0.1%
0.1%
October
0.1%
0.1%
0.4%
2.1%
November
6.2%
9.6%
8.6%
7.7%
December
6.8%
5.5%
4.3%
4.4%
Neighboring states
Maryland: arrives late October, in the same week than Pennsylvania
Delaware: arrives late October, in the same week than Pennsylvania
New Jersey: arrives late October, in the same week than Pennsylvania
Common questions
When do Buffleheads arrive in Pennsylvania?
Buffleheads are winter birds in Pennsylvania: they arrive in late October, peak in late March (11% of checklists), and most are gone by mid April.
When do Buffleheads leave Pennsylvania?
Most Buffleheads have left Pennsylvania by mid April, when reports fall below half their usual rate. Stragglers are still reported until early May.
When is the best time to see a Bufflehead in Pennsylvania?
The Bufflehead is reported most often in late March, on about 11% of Pennsylvania checklists.
Where in Pennsylvania are Buffleheads seen most often?
By county, Montour County, Crawford County, and Erie County have the highest peak reporting rates for the Bufflehead (counties with at least 200 checklists).