Over 60 living species of flightless birds currently exist, ranging in size from the gigantic ostrich to the tiny woodhen. Here are some you may or may not have heard of.

Ostrich

There are two living species of ostrich, the Common ostrich, and the Somali ostrich. Sadly, both of these birds are flightless. It’s easy to recognize that ostriches can’t fly since their heavy bodies are definitely too big for their smaller wings to carry.

The full-grown Common ostrich can weigh anywhere between 139 to 320 pounds. They can also run at speeds of up to 34 mph, with occasional short bursts of up to 43 mph, earning them the title of the fastest land bird. Maybe their remarkable swiftness compensates for their inability to fly?

Emu

The emu is second in size only to the ostrich, with wings smaller than a crow’s; hence, this bird is flightless. Emus are nearly as fast as ostriches, with a maximum running speed of about 30 mph.

Cassowary

Emus, ostriches, and cassowaries are all ratites—non-flying birds without a keel on their sternum bone. There are three living species of cassowary: the Dwarf cassowary, the Southern cassowary, and the Northern cassowary. Cassowaries are the third-tallest bird in existence behind the ostrich and emu. However, they are the second-heaviest—beating out the emu for that title.

Rhea

Another ratite is the rhea, a flightless bird that, notwithstanding its smaller size, greatly resembles the ostrich and the emu. There are two living species of rhea: the Greater rhea and Darwin’s rhea. Rheas have bigger wings in proportion to the rest of their body than other ratites. Nevertheless, they still can’t fly.

Kiwi

Kiwi birds are ratites as well. However, they are much smaller than the birds listed above. In fact, they are the smallest living ratites, being roughly about the size of a domestic chicken. There are currently five existing species of kiwi—the Southern brown kiwi, the Great spotted kiwi, the Northern Island kiwi, the Little spotted kiwi, and the Okarito kiwi—although many of their populations are fragmented and vulnerable due to over-hunting.

Penguin

There are at least 18 living species of penguins. However, while they do have wings, none of these birds can fly. Instead, their wings work more like fins and are often used for swimming. Penguins can swim at a rate of 25 mph.

Penguins’ wing-like flippers frequently come in handy, as the aquatic bird spends up to 75 percent of its life in the water.

Steamer Duck

The four species of steamer ducks all reside in the warmth of South America, specifically in both Chile and Argentina. All but one of these species is flightless. Instead of flying south for the winter, these ducks stay put. After all, their habitat is already warm in the winter months—and they can’t fly anyway.

The flying steamer duck is the only species out of the four that can fly. The other, flightless species are the Fuegian steamer duck, the Falkland steamer duck, and the Chubut steamer duck.

Grebe

Grebes are waterfowl that include two living species: the Junín grebe and the Titicaca grebe. The Junín grebes only number 250 in total. Both species are made up of small, flightless birds that resemble ducks and live in lakes.

Woodhen

The family of Gruiformes, which includes cranes, rails, and coots, encompasses a plethora of flightless birds such as woodhens. Among this hail the Lord Howe woodhen, the Samoan woodhen, and the Makira woodhen, which all lack the ability to fly.

The Makira woodhen has not been seen since 1953 and maybe extinct as a result of habitat loss and feral cats. However, though reported to be extinct in the 1870s, the nocturnal Samoan woodhen has possibly been sighted as recently as 2003. Found only on Lord Howe island near Australia, the flightless Lord Howe woodhen is currently listed as endangered.

Flightless Cormorant

The black double-crested cormorant is often seen hanging around lakes in the United States. It can fly quite well. However, the species of cormorant located on the Galapagos Islands can’t fly at all. The flightless, or Galapagos cormorant is the largest living cormorant, but its wings are only about one-third of the size necessary for flight.

Kakapo

The kakapo is an oddity of the parrot family. Also known as the owl parrot, this particular species of parrot is unlike its fellows in that it is flightless and nocturnal as well as a ground-dwelling herbivore and has a polygynous lek breeding system. The kakapo is currently on the endangered list.