Kagu: Rhynochetidae

Like many island bird species, the ancestors of the kagus lost their powers of flight and became ground-living animals. With no predators to fear and plenty of food on the forest floors, kagus had no need of flight and the enormous amounts of energy that flying requires. So the ancestral kagus gave up flying, keeping large wings for display purposes. They were safe on the ground and must have been quite numerous, even into the hundreds of thousands, until the arrival of humans on the islands.

Kagu species, living and extinct, were hunted for food and for ornamental feathers by the native people of New Caledonia, and this most likely pushed the extinct kagu out of existence. European settlers captured kagus for keeping as pets or for use of their feathers as decorative hat plumes, which were popular in the early 1900s.

Other major, human-made threats to kagus include loss of habitat and fragmentation of populations. Forests are being cleared for agriculture and especially for mining, since Grand Terre has some of the world's most abundant supplies of nickel ore. Once free to roam all over the island, the original population of kagus is split up and isolated into small pockets throughout Grand Terre. This is not good for breeding, since there is no free exchange of genes across a large population, which is the healthy state of things in a wild species.