Mergus merganser
Silhouette: Andy Wilson · PhyloPic
In 3 days >90%
The common merganser or goosander (Mergus merganser) is a large sea duck of rivers and lakes in forested areas of Europe, Asia, and North America. The common merganser eats mainly fish. It nests in holes in trees. The name "common merganser" is used in North America, while "goosander" is used in Eurasia.
The first formal description of the common merganser was written by Swedish naturalist Carl Linnaeus in 1758 in the 10th edition of his Systema Naturae. He introduced the current binomial name Mergus merganser. The genus name is a Latin word used by Pliny and other Roman authors to refer to an unspecified waterbird, and merganser is derived from mergus and anser, Latin for "goose". In 1843 John James Audubon used the name "Buff-breasted Merganser" in addition to "goosander" in his book The Birds of America.
The three subspecies differ in only minor detail: It is 58–72 cm (23–28+1⁄2 in) long with a 78–97 cm (30+1⁄2–38 in) wingspan and a weight of 0.9–2.1 kg (2 lb 0 oz – 4 lb 10 oz); males are on average slightly larger than females, but with some overlap. Like other species in the genus Mergus, it has a crest of longer head feathers, but these usually... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Calgary | 🇨🇦 Canada | |
| 2 | Helsinki | 🇫🇮 Finland | |
| 3 | Lanzhou | 🇨🇳 China | |
| 4 | Sacramento | 🇺🇸 United States | |
| 5 | Taiyuan | 🇨🇳 China | |
| 6 | Sendai | 🇯🇵 Japan | |
| 7 | Munich | 🇩🇪 Germany | |
| 8 | Birmingham | 🇬🇧 United Kingdom | |
| 9 | Warsaw | 🇵🇱 Poland | |
| 10 | Manchester | 🇬🇧 United Kingdom |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Prague Zoo | 🇨🇿 Czechia | |
| 2 | Dresden Zoo | 🇩🇪 Germany | |
| 3 | Zoo Pilsen | 🇨🇿 Czechia | |
| 4 | Bronx Zoo | 🇺🇸 United States | |
| 5 | Toledo Zoo | 🇺🇸 United States | |
| 6 | Berlin Zoological Garden | 🇩🇪 Germany | |
| 7 | Centro Cicogne e Anatidi | 🇮🇹 Italy | |
| 8 | Cologne Zoological Garden | 🇩🇪 Germany | |
| 9 | London Zoo | 🇬🇧 United Kingdom | |
| 10 | Oasi Naturalistica di Sant'Alessio | 🇮🇹 Italy | |
| 11 | Queens Zoo | 🇺🇸 United States | |
| 12 | Stone Zoo | 🇺🇸 United States | |
| 13 | Bayerwald-Tierpark Lohberg | 🇩🇪 Germany | |
| 14 | Alpenzoo Innsbruck | 🇦🇹 Austria | |
| 15 | Central Park Zoo | 🇺🇸 United States | |
| 16 | Aquarium Berlin | 🇩🇪 Germany | |
| 17 | Rákosův pavilon | 🇨🇿 Czechia | |
| 18 | Velemlokárium | 🇨🇿 Czechia | |
| 19 | Cologne Zoo Aquarium | 🇩🇪 Germany | |
| 20 | Les Oiseaux du Marais Poitevin | 🇫🇷 France |
Very likely
About 70% of wildlife watchers report a Common Merganser sighting in Katmai National Park on a given day, based on 213 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 4th most-seen of the 93 birds we can rate there. Over three days the chance rises to over 90%, if each day is a fresh chance.
July and September
In those months about 80% of wildlife watchers report a Common Merganser in Katmai National Park on a given day, against about 30% in May, the lowest month. April and October–February have too few records to rate.
Between 3 and 6 pm
Across all the parks we cover, that three-hour window holds the most Common Merganser sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 48 parks where we can rate Common Merganser sightings, Katmai National Park has the highest daily chance: about 70%. Next come Isle Royale National Park (United States, about 60%) and Plitvice Lakes National Park (Croatia, about 40%). All parks ranked.
GBIF citizen-science records
It is estimated from how often the Common Merganser is recorded against all the birds logged in Katmai National Park (213 verified sightings from 2019 to 2026), 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.
