There are around 40 species of flightless birds worldwide. The smallest flightless bird is the Inaccessible Island Rail at just 12.5 c.m. Stephens Island Wren was even smaller, but it is now extinct. The inaccessible Island, a protected wildlife reserve, is an extinct volcano, which is part of the Tristan da Cunha archipelago, in the South Atlantic Ocean. It has never had any permanent human population.
The largest and heaviest flightless bird is the ostrich at around 2.7 metres tall and weighing 156 kg. It is believed that some extinct species grew a lot larger. Once farmed for its feathers, the ostrich is farmed today for its meat and skin, which is used to make leather.
New Zealand, the last country to be inhabited by man, still has the most varieties of flightless birds over any other country, giving it a special edge to its ecology. They are the kiwi, several species of penguins and takahe. It is believed this occurred as there were no large land predators in New Zealand, prior to the arrival of human beings. Other large birds were the main predator of the flightless birds.
It is believed that a total of 57 flightless birds have become extinct in New Zealand, since the advent of human visitors. Maoris hunting for food, indiscriminate forest burning, and the introduction of Polynesian rats and dogs, account for the first 38 extinctions. Since European arrival there have been a further 19 extinctions caused through logging, forest clearing for pasture and the introduction of predatory animals and birds. The major losses have included 14 species of moas, 11 rails, 6 wrens and two species of eagles.
Second only to the elephant bird of Madagascar, the largest moa was the tallest bird on earth, with its back believed to be 2 metres above the ground. The Moa lived in an environment that was dominated by bird life. Before man, its only predator was the Haast eagle, the world’s largest eagle, with a wing span of 3 m. The eagle would dive on the moa at speeds of up to 80kph, crushing and piercing the moa’s neck, with talons the size of tiger’s claws.
Over a period of merely 100 years, the 14 species of moas were hunted to extinction, as well as the Haast eagle. The moas were already in decline when man arrived, however, they created the fastest known extermination in the world of an entire fauna of large creatures.
Another very interesting bird, now extinct from the Indian Ocean island of Mauritius, is the dodo bird.
The expression ‘dead as a dodo’, means indisputably dead. To ‘go the way of the dodo’ is to become a thing of the past, extinct or obsolete.