Season shown in 0 of Ohio's 88 counties. Its mapped range covers 88. Explore Ohio
No result yet (0)
Within its mapped range (39)
Recorded, too few records for a result (39)
Recorded, season not shown (10)
Season shown (0)
Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files, 1:500,000. Range: USGS Gap Analysis Project, Species Range Maps CONUS_2001 (2018). Show as a table
Counties as a table
Bufflehead by Ohio county: records and mapped range
County
Records
In mapped range
Adams County
No qualifying records yet
Yes: winter
Allen County
Recorded, too few records for a result
Yes: winter
Ashland County
Recorded, too few records for a result
Yes: winter
Ashtabula County
Recorded, too few records for a result
Yes: winter
Athens County
Recorded, too few records for a result
Yes: migration
Auglaize County
Recorded, too few records for a result
Yes: winter
Belmont County
Recorded, too few records for a result
Yes: migration
Brown County
Recorded, too few records for a result
Yes: winter
Butler County
Recorded, too few records for a result
Yes: winter
Carroll County
No qualifying records yet
Yes: winter, migration
Champaign County
Recorded, too few records for a result
Yes: winter
Clark County
Recorded, too few records for a result
Yes: winter
Clermont County
Recorded, too few records for a result
Yes: winter
Clinton County
No qualifying records yet
Yes: winter
Columbiana County
Recorded, too few records for a result
Yes: winter, migration
Coshocton County
No qualifying records yet
Yes: winter
Crawford County
No qualifying records yet
Yes: winter
Cuyahoga County
150 · Recorded, season not shown
Yes: winter
Darke County
Recorded, too few records for a result
Yes: winter
Defiance County
No qualifying records yet
Yes: winter
Delaware County
Recorded, too few records for a result
Yes: winter
Erie County
Recorded, too few records for a result
Yes: winter
Fairfield County
No qualifying records yet
Yes: winter
Fayette County
No qualifying records yet
Yes: winter
Franklin County
23 · Recorded, season not shown
Yes: winter
Fulton County
No qualifying records yet
Yes: winter
Gallia County
No qualifying records yet
Yes: migration
Geauga County
Recorded, too few records for a result
Yes: winter
Greene County
Recorded, too few records for a result
Yes: winter
Guernsey County
Recorded, too few records for a result
Yes: winter, migration
Hamilton County
94 · Recorded, season not shown
Yes: winter
Hancock County
Recorded, too few records for a result
Yes: winter
Hardin County
No qualifying records yet
Yes: winter
Harrison County
Recorded, too few records for a result
Yes: winter, migration
Henry County
Recorded, too few records for a result
Yes: winter
Highland County
Recorded, too few records for a result
Yes: winter
Hocking County
Recorded, too few records for a result
Yes: winter
Holmes County
No qualifying records yet
Yes: winter
Huron County
No qualifying records yet
Yes: winter
Jackson County
No qualifying records yet
Yes: winter, migration
Jefferson County
No qualifying records yet
Yes: migration
Knox County
No qualifying records yet
Yes: winter
Lake County
25 · Recorded, season not shown
Yes: winter
Lawrence County
No qualifying records yet
Yes: migration
Licking County
Recorded, too few records for a result
Yes: winter
Logan County
Recorded, too few records for a result
Yes: winter
Lorain County
36 · Recorded, season not shown
Yes: winter
Lucas County
38 · Recorded, season not shown
Yes: winter
Madison County
No qualifying records yet
Yes: winter
Mahoning County
Recorded, too few records for a result
Yes: winter, migration
Marion County
No qualifying records yet
Yes: winter
Medina County
23 · Recorded, season not shown
Yes: winter
Meigs County
No qualifying records yet
Yes: migration
Mercer County
Recorded, too few records for a result
Yes: winter
Miami County
No qualifying records yet
Yes: winter
Monroe County
No qualifying records yet
Yes: migration
Montgomery County
Recorded, too few records for a result
Yes: winter
Morgan County
No qualifying records yet
Yes: winter, migration
Morrow County
Recorded, too few records for a result
Yes: winter
Muskingum County
Recorded, too few records for a result
Yes: winter, migration
Noble County
No qualifying records yet
Yes: migration
Ottawa County
Recorded, too few records for a result
Yes: winter
Paulding County
No qualifying records yet
Yes: winter
Perry County
No qualifying records yet
Yes: winter
Pickaway County
No qualifying records yet
Yes: winter
Pike County
No qualifying records yet
Yes: winter
Portage County
41 · Recorded, season not shown
Yes: winter
Preble County
No qualifying records yet
Yes: winter
Putnam County
No qualifying records yet
Yes: winter
Richland County
Recorded, too few records for a result
Yes: winter
Ross County
No qualifying records yet
Yes: winter
Sandusky County
No qualifying records yet
Yes: winter
Scioto County
No qualifying records yet
Yes: winter, migration
Seneca County
Recorded, too few records for a result
Yes: winter
Shelby County
No qualifying records yet
Yes: winter
Stark County
23 · Recorded, season not shown
Yes: winter
Summit County
118 · Recorded, season not shown
Yes: winter
Trumbull County
Recorded, too few records for a result
Yes: winter, migration
Tuscarawas County
Recorded, too few records for a result
Yes: winter
Union County
No qualifying records yet
Yes: winter
Van Wert County
No qualifying records yet
Yes: winter
Vinton County
No qualifying records yet
Yes: winter, migration
Warren County
Recorded, too few records for a result
Yes: winter
Washington County
No qualifying records yet
Yes: migration
Wayne County
Recorded, too few records for a result
Yes: winter
Williams County
No qualifying records yet
Yes: winter
Wood County
Recorded, too few records for a result
Yes: winter
Wyandot County
Recorded, too few records for a result
Yes: winter
Season
When it is recorded
In Hamilton County
Not enough evidence
The weeks are still too uncertain to show a season. Based on 94 records in 10 of the 10 years from 2016 to 2025, above the minimum of 20 records from 5 different years.
JanFebMarAprMayJunJulAugSepOctNovDec
Show over the bars
Recording in Hamilton County · records of all species each week, 87,019 in all
Records per week from 94 records in 10 of the 10 years from 2016 to 2025. Shows when people recorded it, not a season or how common it is.
Show as a table
Records of Bufflehead in Hamilton County each week, and records of all species
Week
Records of Bufflehead
Years recorded
Records of all species
Jan 4–10
4
1
392
Jan 11–17
4
3
344
Jan 18–24
9
4
312
Jan 25–31
0
0
206
Feb 1–7
4
3
357
Feb 8–14
4
3
383
Feb 15–21
10
2
366
Feb 22–28
5
3
391
Mar 1–7
7
3
551
Mar 8–14
4
2
523
Mar 15–21
5
3
750
Mar 22–28
2
1
1,012
Mar 29 – Apr 4
1
1
1,535
Apr 5–11
1
1
1,960
Apr 12–18
0
0
2,492
Apr 19–25
1
1
2,403
Apr 26 – May 2
1
1
3,783
May 3–9
0
0
3,307
May 10–16
0
0
2,059
May 17–23
0
0
2,153
May 24–30
0
0
2,390
May 31 – Jun 6
0
0
2,648
Jun 7–13
0
0
2,715
Jun 14–20
0
0
2,695
Jun 21–27
0
0
2,714
Jun 28 – Jul 4
0
0
3,220
Jul 5–11
0
0
2,980
Jul 12–18
1
1
3,031
Jul 19–25
1
1
2,961
Jul 26 – Aug 1
0
0
2,795
Aug 2–8
1
1
2,884
Aug 9–15
0
0
2,696
Aug 16–22
0
0
2,535
Aug 23–29
0
0
2,536
Aug 30 – Sep 5
0
0
2,606
Sep 6–12
0
0
2,980
Sep 13–19
0
0
2,959
Sep 20–26
0
0
2,313
Sep 27 – Oct 3
0
0
2,122
Oct 4–10
0
0
1,828
Oct 11–17
0
0
1,793
Oct 18–24
0
0
1,338
Oct 25–31
0
0
1,023
Nov 1–7
0
0
676
Nov 8–14
1
1
593
Nov 15–21
1
1
384
Nov 22–28
7
5
496
Nov 29 – Dec 5
4
3
356
Dec 6–12
4
3
478
Dec 13–19
6
3
285
Dec 20–26
2
2
322
Dec 27 – Jan 2
4
1
388
In Ohio
Late November to mid-April, middle week Mar 1–7
Middle week · Mar 1–7
This week · Nov 8–14
JanFebMarAprMayJunJulAugSepOctNovDec
Show over the bars
Recording in Ohio · records of all species each week, 1,691,199 in all
Records per week from 1,033 records in 10 of the 10 years from 2016 to 2025. Shows when people recorded it, not how common it is. The grey bars show how many records of all species were made here each week, so you can see when recording itself was high or low; the season is not adjusted by them.
Recorded on 576 dates. Latest record: December 2025.
Show as a table
Records of Bufflehead in Ohio each week, and records of all species
Week
Records of Bufflehead
Years recorded
Records of all species
Jan 4–10
41
9
6,211
Jan 11–17
36
8
5,146
Jan 18–24
26
9
4,645
Jan 25–31
22
8
4,698
Feb 1–7
30
6
6,023
Feb 8–14
19
7
5,888
Feb 15–21
31
9
5,436
Feb 22–28
41
9
6,846
Mar 1–7
36
10
8,321
Mar 8–14
70
9
10,384
Mar 15–21
79
10
12,620
Mar 22–28
87
8
13,949
Mar 29 – Apr 4
91
10
19,661
Apr 5–11
56
9
26,860
Apr 12–18
50
9
39,925
Apr 19–25
34
9
41,623
Apr 26 – May 2
17
8
56,391
May 3–9
11
7
52,952
May 10–16
2
2
53,785
May 17–23
3
2
57,698
May 24–30
0
0
54,651
May 31 – Jun 6
0
0
53,099
Jun 7–13
1
1
53,700
Jun 14–20
0
0
56,625
Jun 21–27
0
0
55,361
Jun 28 – Jul 4
0
0
58,477
Jul 5–11
0
0
61,336
Jul 12–18
1
1
64,722
Jul 19–25
1
1
69,753
Jul 26 – Aug 1
0
0
59,416
Aug 2–8
1
1
59,712
Aug 9–15
0
0
55,994
Aug 16–22
0
0
54,328
Aug 23–29
0
0
51,772
Aug 30 – Sep 5
0
0
57,167
Sep 6–12
0
0
59,075
Sep 13–19
0
0
54,543
Sep 20–26
0
0
45,860
Sep 27 – Oct 3
0
0
43,180
Oct 4–10
0
0
37,841
Oct 11–17
0
0
30,824
Oct 18–24
2
2
21,156
Oct 25–31
0
0
19,021
Nov 1–7
1
1
14,172
Nov 8–14
19
7
12,621
Nov 15–21
20
9
7,965
Nov 22–28
54
8
8,136
Nov 29 – Dec 5
37
9
6,083
Dec 6–12
15
6
6,004
Dec 13–19
44
9
5,423
Dec 20–26
27
9
5,661
Dec 27 – Jan 2
28
8
8,459
What these results show
These results show when people recorded a species, not when or where it occurs. Missing weeks and low counts do not mean absence or scarcity, and counts are not abundance. Contributed records reflect where, when and what people chose to observe.
Identification
How to identify it
Telling it apart
From what Ohio’s records show. Only what the records support is shown.
Hooded MerganserLophodytes cucullatusOften confused in Ohio: 10 identifications in Ohio named one where the other was meant
Common GoldeneyeBucephala clangula184 identifications worldwide named one where the other was meant
Ruddy DuckOxyura jamaicensis72 identifications worldwide named one where the other was meant
Common MerganserMergus merganser38 identifications worldwide named one where the other was meant
MallardAnas platyrhynchos31 identifications worldwide named one where the other was meant
From iNaturalist’s similar-species counts, refreshed monthly: confusions in Ohio first, then worldwide. Only species with an Ohio result are listed.
Months not reported
Jan: recorded
Feb: recorded
Mar: recorded
Apr: recorded
May: recorded
Jun: recorded
Jul: recorded
Aug: recorded
Sep: no record
Oct: recorded
Nov: recorded
Dec: recorded
Not reported in Ohio in September, 2016 to 2025.
Land cover where it is recorded
Land cover
Its recordsAll Ohio records
Open water
57%3%
Developed
18%49%
Wetland
14%5%
Farmland
4%11%
Forest
4%31%
Grassland and shrub
2%0.9%
Barren
1%0.6%
From 409 records placed within 100 m, beside all Ohio records placed the same way. People record where they go, so this shows where records come from, not where the species lives. Land cover: USGS Annual NLCD, 2025 (opens in a new tab)
Sources
Where these results come from
Records from iNaturalist research-grade observations and expert-identified GBIF datasets, CC0, CC BY and CC BY-NC. Sources
Seasons use the published method and its evidence thresholds. Methods
A spreadsheet (CSV) with a link to each record, on iNaturalist or GBIF. Records whose location was hidden by the observer or the source are counted but not linked.
