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Nearby · Hamilton Co.
Lesser Scaup (Aythya affinis)
(c) Ad Konings, some rights reserved (CC BY-NC), uploaded by Ad Konings · CC BY-NC 4.0 (opens in a new tab) · iNaturalist (opens in a new tab)
BirdsIn Hamilton County, Ohio

Lesser Scaup

Aythya affinis (Eyton, 1838)

Lesser Scaup in all of Ohio
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Anseriformes
Family
Anatidae
Genus
Aythya
Near Hamilton County

Range

Where it is recorded

Season shown in 3 of Ohio's 88 counties. Its mapped range covers 88. Explore Ohio

  • No result yet (0)
  • Within its mapped range (35)
  • Recorded, too few records for a result (46)
  • Recorded, season not shown (4)
  • Season shown (3)
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
Lesser Scaup by Ohio county: records and mapped range
CountyRecordsIn mapped range
Adams CountyRecorded, too few records for a resultYes: migration
Allen CountyRecorded, too few records for a resultYes: migration
Ashland CountyNo qualifying records yetYes: migration
Ashtabula CountyNo qualifying records yetYes: migration
Athens CountyRecorded, too few records for a resultYes: migration
Auglaize CountyRecorded, too few records for a resultYes: migration
Belmont CountyNo qualifying records yetYes: migration
Brown CountyNo qualifying records yetYes: migration
Butler CountyRecorded, too few records for a resultYes: migration
Carroll CountyNo qualifying records yetYes: migration
Champaign CountyRecorded, too few records for a resultYes: migration
Clark CountyRecorded, too few records for a resultYes: migration
Clermont CountyRecorded, too few records for a resultYes: migration
Clinton CountyRecorded, too few records for a resultYes: migration
Columbiana CountyNo qualifying records yetYes: migration
Coshocton CountyNo qualifying records yetYes: migration
Crawford CountyRecorded, too few records for a resultYes: migration
Cuyahoga County60 · Recorded, season not shownYes: migration
Darke CountyRecorded, too few records for a resultYes: migration
Defiance CountyNo qualifying records yetYes: migration
Delaware CountyRecorded, too few records for a resultYes: migration
Erie CountyRecorded, too few records for a resultYes: migration
Fairfield CountyNo qualifying records yetYes: migration
Fayette CountyRecorded, too few records for a resultYes: migration
Franklin County20 · Season shownYes: migration
Fulton CountyNo qualifying records yetYes: migration
Gallia CountyNo qualifying records yetYes: migration
Geauga CountyRecorded, too few records for a resultYes: migration
Greene CountyRecorded, too few records for a resultYes: migration
Guernsey CountyRecorded, too few records for a resultYes: migration
Hamilton County20 · Season shownYes: migration
Hancock CountyRecorded, too few records for a resultYes: migration
Hardin CountyRecorded, too few records for a resultYes: migration
Harrison CountyRecorded, too few records for a resultYes: migration
Henry CountyNo qualifying records yetYes: migration
Highland CountyNo qualifying records yetYes: migration
Hocking CountyRecorded, too few records for a resultYes: migration
Holmes CountyNo qualifying records yetYes: migration
Huron CountyRecorded, too few records for a resultYes: migration
Jackson CountyNo qualifying records yetYes: migration
Jefferson CountyNo qualifying records yetYes: migration
Knox CountyRecorded, too few records for a resultYes: migration
Lake County20 · Recorded, season not shownYes: migration
Lawrence CountyNo qualifying records yetYes: migration
Licking CountyRecorded, too few records for a resultYes: migration
Logan CountyRecorded, too few records for a resultYes: migration
Lorain County35 · Recorded, season not shownYes: migration
Lucas County61 · Recorded, season not shownYes: migration
Madison CountyNo qualifying records yetYes: migration
Mahoning CountyNo qualifying records yetYes: migration
Marion CountyRecorded, too few records for a resultYes: migration
Medina CountyRecorded, too few records for a resultYes: migration
Meigs CountyNo qualifying records yetYes: migration
Mercer CountyRecorded, too few records for a resultYes: migration
Miami CountyNo qualifying records yetYes: migration
Monroe CountyNo qualifying records yetYes: migration
Montgomery CountyRecorded, too few records for a resultYes: migration
Morgan CountyNo qualifying records yetYes: migration
Morrow CountyNo qualifying records yetYes: migration
Muskingum CountyRecorded, too few records for a resultYes: migration
Noble CountyNo qualifying records yetYes: migration
Ottawa CountyRecorded, too few records for a resultYes: migration
Paulding CountyRecorded, too few records for a resultYes: migration
Perry CountyRecorded, too few records for a resultYes: migration
Pickaway CountyNo qualifying records yetYes: migration
Pike CountyNo qualifying records yetYes: migration
Portage CountyRecorded, too few records for a resultYes: migration
Preble CountyRecorded, too few records for a resultYes: migration
Putnam CountyNo qualifying records yetYes: migration
Richland CountyRecorded, too few records for a resultYes: migration
Ross CountyNo qualifying records yetYes: migration
Sandusky CountyNo qualifying records yetYes: migration
Scioto CountyRecorded, too few records for a resultYes: migration
Seneca CountyNo qualifying records yetYes: migration
Shelby CountyNo qualifying records yetYes: migration
Stark CountyRecorded, too few records for a resultYes: migration
Summit County89 · Season shownYes: migration
Trumbull CountyRecorded, too few records for a resultYes: migration
Tuscarawas CountyNo qualifying records yetYes: migration
Union CountyNo qualifying records yetYes: migration
Van Wert CountyRecorded, too few records for a resultYes: migration
Vinton CountyRecorded, too few records for a resultYes: migration
Warren CountyRecorded, too few records for a resultYes: migration
Washington CountyRecorded, too few records for a resultYes: migration
Wayne CountyRecorded, too few records for a resultYes: migration
Williams CountyRecorded, too few records for a resultYes: migration
Wood CountyNo qualifying records yetYes: migration
Wyandot CountyRecorded, too few records for a resultYes: migration

Season

When it is recorded

In Hamilton County

Mid-February to early April, middle week Mar 8–14

Show over the bars
Recording in Hamilton County · records of all species each week, 87,019 in all

Records per week from 20 records in 6 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 19 dates. Latest record: April 2025.

Show as a table
Records of Lesser Scaup in Hamilton County each week, and records of all species
WeekRecords of Lesser ScaupYears recordedRecords of all species
Jan 4–1000392
Jan 11–1700344
Jan 18–2400312
Jan 25–3100206
Feb 1–711357
Feb 8–1400383
Feb 15–2143366
Feb 22–2822391
Mar 1–700551
Mar 8–1442523
Mar 15–2132750
Mar 22–28321,012
Mar 29 – Apr 4111,535
Apr 5–11111,960
Apr 12–18002,492
Apr 19–25002,403
Apr 26 – May 2113,783
May 3–9003,307
May 10–16002,059
May 17–23002,153
May 24–30002,390
May 31 – Jun 6002,648
Jun 7–13002,715
Jun 14–20002,695
Jun 21–27002,714
Jun 28 – Jul 4003,220
Jul 5–11002,980
Jul 12–18003,031
Jul 19–25002,961
Jul 26 – Aug 1002,795
Aug 2–8002,884
Aug 9–15002,696
Aug 16–22002,535
Aug 23–29002,536
Aug 30 – Sep 5002,606
Sep 6–12002,980
Sep 13–19002,959
Sep 20–26002,313
Sep 27 – Oct 3002,122
Oct 4–10001,828
Oct 11–17001,793
Oct 18–24001,338
Oct 25–31001,023
Nov 1–700676
Nov 8–1400593
Nov 15–2100384
Nov 22–2800496
Nov 29 – Dec 500356
Dec 6–1200478
Dec 13–1900285
Dec 20–2600322
Dec 27 – Jan 200388

In Ohio

Mid-December to early May, middle week Mar 15–21

Show over the bars
Recording in Ohio · records of all species each week, 1,691,199 in all

Records per week from 667 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 420 dates. Latest record: December 2025.

Show as a table
Records of Lesser Scaup in Ohio each week, and records of all species
WeekRecords of Lesser ScaupYears recordedRecords of all species
Jan 4–101146,211
Jan 11–17655,146
Jan 18–24424,645
Jan 25–311474,698
Feb 1–71776,023
Feb 8–142465,888
Feb 15–212585,436
Feb 22–283486,846
Mar 1–754108,321
Mar 8–1447910,384
Mar 15–2168912,620
Mar 22–28541013,949
Mar 29 – Apr 4481019,661
Apr 5–11451026,860
Apr 12–1849939,925
Apr 19–2540941,623
Apr 26 – May 212656,391
May 3–913652,952
May 10–1614653,785
May 17–236457,698
May 24–305454,651
May 31 – Jun 60053,099
Jun 7–133253,700
Jun 14–202256,625
Jun 21–272255,361
Jun 28 – Jul 42258,477
Jul 5–111161,336
Jul 12–183364,722
Jul 19–251169,753
Jul 26 – Aug 12259,416
Aug 2–80059,712
Aug 9–151155,994
Aug 16–220054,328
Aug 23–290051,772
Aug 30 – Sep 50057,167
Sep 6–121159,075
Sep 13–190054,543
Sep 20–261145,860
Sep 27 – Oct 30043,180
Oct 4–100037,841
Oct 11–170030,824
Oct 18–241121,156
Oct 25–312219,021
Nov 1–73314,172
Nov 8–143212,621
Nov 15–21117,965
Nov 22–28438,136
Nov 29 – Dec 5446,083
Dec 6–12646,004
Dec 13–19555,423
Dec 20–261255,661
Dec 27 – Jan 21768,459

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.

Relatives

In the same genus

Other Aythya recorded in Hamilton County

CanvasbackAythya valisineriaRedheadAythya americanaRing-necked DuckAythya collaris

Identification

How to identify it

Often confused with

  • Greater Scaup Aythya marilaOften confused in Ohio: 27 identifications in Ohio named one where the other was meant
  • Ring-necked Duck Aythya collarisOften confused in Ohio: 12 identifications in Ohio named one where the other was meant
  • Redhead Aythya americana71 identifications worldwide named one where the other was meant
  • Mallard Anas platyrhynchos43 identifications worldwide named one where the other was meant
  • Common Goldeneye Bucephala clangula39 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.

When each is reported

  • All recordsUsually mid-December to early May, middle week mid-March · 667 records
  • Reported as maleUsually early February to late April, middle week mid-March · 22 records

Not every photo is marked with a sex or a sign, so these show when people reported each, not when it happens.

Land cover where it is recorded

Land coverIts recordsAll Ohio records
Open water65%3%
Developed25%49%
Farmland4%11%
Forest2%31%
Grassland and shrub2%0.9%
Wetland2%5%
Barren0.8%0.6%

From 257 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
  • See it on iNaturalist (opens in a new tab)OpenPhenology is independent and not affiliated with iNaturalist.

Records behind the Hamilton County result

20 records from 2 datasets.

To cite: the GBIF download doi:10.15468/dl.y2jkt8 (opens in a new tab).

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.