Aythya affinis
Silhouette: Andy Wilson · PhyloPic
In 3 days ~20% in a week ~40%
The lesser scaup (Aythya affinis) is a small North American diving duck that migrates south as far as Central America in winter. It is colloquially known as the little bluebill or broadbill because of its distinctive blue bill. The origin of the name scaup may stem from the bird's preference for feeding on scalp—the Scottish word for clams, oysters, and mussels; however, some credit it to the female's discordant scaup call as the name's source. It is apparently a very close relative of the Holarctic greater scaup or "bluebill" (A. marila), with which it forms a superspecies. The scientific name is derived from Ancient Greek and Latin, with aithuia being an Ancient Greek term for an unidentified seabird, used by Hesychius and Aristotle, among other authors, and affinis, Latin for "related to", from the lesser scaup's resemblance to the greater scaup.
Adults are 38–48 cm (15–19 in) long, 41.7–43 cm (16.4–16.9 in) on average. The species can weigh 454–1,089 g (1.001–2.401 lb); males weigh 820 g (1.81 lb) on average while females weigh noticeably less, at 730 g (1.61 lb) on average. Wing lengths (not wingspans) are about 7.5–7.9 in (19–20 cm) in males and 7.3–7.8 in (19... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Ciudad Juárez | 🇲🇽 México | |
| 2 | Anchorage | 🇺🇸 United States | |
| 3 | Calgary | 🇨🇦 Canada | |
| 4 | Mesa | 🇺🇸 United States | |
| 5 | Edmonton | 🇨🇦 Canada | |
| 6 | Austin | 🇺🇸 United States | |
| 7 | San Diego | 🇺🇸 United States | |
| 8 | Denver | 🇺🇸 United States | |
| 9 | Vancouver | 🇨🇦 Canada | |
| 10 | Baltimore | 🇺🇸 United States |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Zoo Pilsen | 🇨🇿 Czechia | |
| 2 | Ecomuseum Zoo | 🇨🇦 Canada | |
| 3 | Columbus Zoo and Aquarium | 🇺🇸 United States | |
| 4 | Slimbridge Wetland Centre | 🇬🇧 United Kingdom | |
| 5 | Hellabrunn Zoo | 🇩🇪 Germany | |
| 6 | Tierpark Hagenbeck | 🇩🇪 Germany | |
| 7 | Salisbury Zoo | 🇺🇸 United States | |
| 8 | Florida Aquarium | 🇺🇸 United States | |
| 9 | Texas State Aquarium | 🇺🇸 United States | |
| 10 | Cologne Zoo Aquarium | 🇩🇪 Germany | |
| 11 | Tierpark Schlichtweg 15 in München | 🇩🇪 Germany | |
| 12 | Zoo Schlichtweg 11 in München | 🇩🇪 Germany | |
| 13 | Zoo Siebenbrunner Straße 6 in München | 🇩🇪 Germany |
With luck
About 10% of wildlife watchers report a Lesser Scaup sighting in San Francisco on a given day, based on 7,651 verified sightings from GBIF citizen-science data. It is the 102nd most-seen of the 375 birds we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
January
In that month about 20% of wildlife watchers report a Lesser Scaup in San Francisco on a given day, against under 5% in May to November, the lowest months. That is one of San Francisco's wettest months, with about 90 mm of rain against almost none in July.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Lesser Scaup sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
11th of 40
Of the 40 cities where we can rate Lesser Scaup sightings, San Francisco ranks 11th at about 10%. The best odds are in Ciudad Juárez (México, about 40%), Anchorage (United States, about 30%) and Calgary (Canada, about 20%).
Same genus: Aythya
The closest relatives of the Lesser Scaup that you can see in San Francisco (genus Aythya, Scaups, Pochards, and Allies) are Greater Scaup (about 10%), Canvasback (about 10%) and Ring-necked Duck (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Lesser Scaup is recorded against all the birds logged in San Francisco (7,651 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
