After weeks of learning about fossils and geologic time, let’s talk about something that’s still alive: ratites.
Ratite comes from the Latin word ‘ratis‘ which means raft. Ratites are large, flightless birds. The name ‘ratite‘ refers to the the large, flat sternum of these birds that lacks a keel. Today, there are five orders of ratites and more than 10 different species.
Ostriches (Struthio camelus) are the world’s largest and fastest birds. They can grow to over 2.5 meters tall and weigh over 100 kilgrams. They live across much of Africa and prefer open savannas and deserts. Ostriches are the only ratites with a native range north of of the Equator.
There are two species of ratite native to South America: the Greater Rhea (Rhea americana) and Darwin’s Rhea (Rhea pennata). The Greater Rhea lives in the open grasslands of southeastern South America, while Darwin’s Rhea lives in Patagonia and the Altiplano of southern and western South America. In 2000, three pairs of rheas escaped from a farm in Germany and have managed to maintain a population. In 2008 this group was estimated at around 100 birds.
The island of New Guinea is native to three species of ratite: the Northern Cassowary (Casuarius unappendiculatus), the Southern Cassowary (Casuarius casuarius) and the Dwarf Cassowary (Casuarius bennetti). Cassowaries live in forests and the range of the Southern Cassowary extends all the way to the northeastern tip of Australia. These species have evolved dagger-like claws on their inner toes and all three are suffering from habitat loss.
Australia is native to the Emu (Dromaius novaehollandiae). They are the world’s second tallest bird, after the ostrich. The emu is the only bird to have gastrocnemius muscles in their legs (the equivalent of the calf muscles in humans). They live throughout Australia and, like the cassowary, have sharp claws on their toes. The emu, with the red kangaroo, is part of the coat of arms of Australia.
The islands of New Zealand are native to five species of ratite: the Great Spotted Kiwi (Apteryx haastii), the Little Spotted Kiwi (Apteryx owenii), the Okarito Kiwi (Apteryx rowi), the Southern Brown Kiwi (Apteryx australis) and the North Island Brown Kiwi (Apteryx mantelli). Kiwis are about the size of a chicken, making them the smallest of the ratites and they lay the largest egg in relation to their body size of any bird. All of these species are suffering the ill effects of habitat destruction (the Okarito Kiwi is critically endangered and the North Island Brown Kiwi is endangered). Kiwis are a national symbol of New Zealand: it is the nickname for New Zealanders and appears on the coat of arms for the country as well as stamps and badges.