How Many Species of Ducks Are There?

There are about 120 species of duck worldwide. That figure sits inside a larger and firmer one: the IOC World Bird List, version 15.2, recognises 174 species in the family Anatidae, which covers ducks, geese and swans together across 53 genera.

The gap between those two numbers is the whole difficulty with this question. "Duck" is an everyday word, not a taxonomic rank, and no committee anywhere publishes an official duck count. The 174 is a hard number you can check. The 120 depends on what you are willing to call a duck.

What is actually in Anatidae

Breaking the family down by the kind of English name each species carries gives a reasonable picture:

| Group | Species | | -------------------------------------------- | ------- | | Ducks in the narrow sense | ~119 | | Geese (including pygmy geese and sheldgeese) | 29 | | Shelducks and sheldgeese | 10 | | Whistling-ducks and the white-backed duck | 9 | | Swans | 7 | | Total (Anatidae, IOC v15.2) | 174 |

Eight of the 174 are extinct, including the Labrador duck, the pink-headed duck, the New Zealand merganser and the crested shelduck. That leaves 166 living species in the family, and roughly 114 living ducks in the narrow sense.

Note the awkward cases. Whistling-ducks are called ducks but sit on an early branch, closer to the base of the family than to mallards. Pygmy geese are tiny perching ducks with "goose" in the name. Shelducks are somewhere between the two, which is exactly what their name says. Any duck total between about 119 and 140 can be justified depending on how you treat those groups.

The main kinds of duck

Within the roughly 119 narrow-sense ducks, the traditional groupings are:

• Dabbling ducks (about 55 species) — mallards, teal, pintails, wigeon, shovelers and gadwall. They feed at the surface and up-end rather than diving, and they can take off straight from the water.
• Sea ducks (about 23) — eiders, scoters, goldeneyes, mergansers, harlequin and long-tailed ducks. Mostly cold-water divers; the mergansers have serrated bills for gripping fish.
• Pochards and diving ducks (about 16) — canvasback, tufted duck, scaup, redhead. They dive from the surface and need a running start to get airborne.
• Stiff-tailed ducks (about 9) — ruddy duck, musk duck, white-headed duck. Small, low-floating, with upright tail feathers.
• Perching ducks (about 8) — wood duck, mandarin, muscovy. They nest in tree cavities.
• Steamer ducks (4) — heavy South American ducks, three of which cannot fly.
• Oddballs (4) — the torrent duck of Andean rapids, New Zealand's blue duck, Australia's pink-eared and freckled ducks. Each sits alone in its own genus.

Our random bird generator pulls from the full IOC list, so waterfowl show up alongside everything else in the class.

How much do the authorities disagree?

Less than you might expect. Compared with a family like the hummingbirds, waterfowl taxonomy is fairly settled. Current global checklists put Anatidae at 172 to 175 species. The older Howard and Moore checklist from 2014 counted 162, which is the usual pattern — a decade of genetic work adds species rather than removing them.

Ducks are unusual among birds in that hybridisation is common and fertile, which complicates species boundaries. Mallards in particular interbreed readily with American black ducks, mottled ducks, Hawaiian ducks and Pacific black ducks. Several of those populations are now genetically swamped by introduced mallards, which is a conservation problem and a taxonomic headache at the same time.

Where ducks live

Anatidae is close to global. Ducks breed on every continent except Antarctica and reach remote islands readily — which is why the family also has an unusually high extinction rate, since island populations often lose the ability to fly and then meet rats, cats and people.

The mallard is probably the most widespread duck on Earth, and nearly all domestic duck breeds descend from it. The one significant exception is the muscovy duck, domesticated separately in South America.

Why "duck" is not a real category

Geese and swans did not evolve from some separate stock and then join the ducks. They are branches inside the same family, and the group left over when you remove them is not a natural unit. Biologists call this paraphyly — the same problem you get with "fish", "reptile", or "monkey" once apes are excluded.

This is why no authority publishes a duck count and every source gives a slightly different figure. The honest answer is: 174 species in Anatidae, of which about 120 are what English speakers mean by "duck."

The short version

Ask for a single number and 120 is the fair answer. Ask for a checkable one and it is 174 species of waterfowl in the family Anatidae, 166 of them still living, per the IOC World Bird List v15.2.

For a broader draw across birds, mammals, fish and the rest, the random animal generator covers the whole animal kingdom.