Although it may be one of the first and unique characteristics that everyone thinks about when it comes to birds, flying isn’t something every bird can do. Nowadays, there are about 60 species that are the exception.
These flightless bird species throughout their evolution lost their ability to fly. Among other reasons, widely available food, absence of predators and climate consistency all year-round are some of the reasons some species didn’t feel the need to fly. This is something that was and is easily found in remote islands.
The fact that the species didn’t need to fly doesn’t mean they lost their wings. The wings stayed, though less developed, and therefore called vestigial wings (something that had a necessary function for a species’ ancestors, but is no longer important for modern species).
Yet, in some cases, the sometimes anatomical and rudimentary wings are still useful. They can help keep balance when running and be used in courtship displays. However, the lack of flying gives these species the disadvantage of not being able to escape introduced predators or natural disasters.
Flightless bird species tend to increase in size and develop strong legs to support the extra weight. That’s why some of the heaviest and largest birds on the planet are flightless.
Among some iconic species, here are some examples of flightless species:
Common Ostrich (Struthio camelus)
The tallest, heaviest and biggest bird in the world. It has an average height of over 2 meters and a weight of up to 160 kg. Its top speed is 69 km/h.
Emperor Penguin (Aptenodytes forsteri)
The tallest and heaviest Penguins are only found in Antarctica. Like other species of Penguins, they are flightless but excellent swimmers.
Emu (Dromaius novaehollandiae)
The Emu is a huge flightless bird endemic to Australia. Similar but smaller than the Ostrich. It is an incredible runner, able to reach 48 kilometres per hour.
Falkland Steamer Duck (Tachyeres brachypterus)
An endemic species to the Falkland Islands and one of the three out of four flightless species of Steamer Ducks (Tachyeres).
Flightless Cormorant (Nannopterum harrisi)
The largest and only member of the cormorant family unable to fly and the only one inhabiting the Galápagos. This species is one of the world’s rarest birds.
Great Rhea (Rhea americana)
The largest bird in South America. It is an extremely fast bird, able to reach 35 kilometres per hour.
Takahe (Porphyrio hochstetteri)
The largest living rail in the world, endemic to New Zealand. The species was thought to be extinct and was rediscovered in 1948.
Great Spotted Kiwi (Apteryx haastii)
One of the five endemic species of Kiwi (Apteryx) to New Zealand. This species is the largest of the kiwi.
Guam Rail (Gallirallus owstoni)
This species lives in Guam Island (United States of America territory) in the north-western Pacific Ocean. It is locally known as Ko’ko’. The species became extinct in the 1980s but has been carefully reintroduced.
Weka (Gallirallus australis)
Large rail is endemic to New Zealand. This chicken-like bird has four subspecies recognised and is vulnerable to extinction.
Kakapo (Strigops habroptilus)
This large critically endangered parrot, also known as Owl Parrot, is another endemic bird to New Zealand. It is nocturnal, solitary and an excellent climber.
Southern Cassowary (Casuarius casuarius)
Enormous flightless birds are found in north-eastern Australia, Indonesia and New Guinea. The biggest of the Cassowary species can reach 1.8 meters tall and 85 kilograms. It is known for killing humans.