Creature Feature #551: ʻŌʻū

The ʻŌʻū was a large, plump finch, endemic to the Hawaiian islands. He favoured a frugivorous diet, feeding predominently on the fruit of the ʻieʻie vine and the buds and blossoms of the ʻōhiʻa lehua (as pictured here). A seasonal migrant, his foraging took him up and down the mountains on the islands, and also between islands. This proved to be his undoing, as it brought him into range of the lower-altitude mosquitoes and, like many of his kin, he fell victim to avian malaria and also fowlpox. The last recorded sighting was in 1989 and although not yet proven extinct (still classified as "Critically endangered"), this unique Hawaiian bird has probably vanished forever.

Creature Feature #545: Oahu Tree Snail

This fellow is an Oahu Tree Snail. They are one of 41 species of large land snail found only on the island of Oahu, Hawaii. They are beautiful - like living jewels. Found in the moist and dry forests, particularly of the mountainous regions, they climb the trees, grazing on fungus. Of these 41 species, some may well be extinct and the others are critically endangered. Why? Because they are predated by introduced pests such as chameleons, rats, and carnivorous rose snail, which was introduced to eliminate the giant land snail (an agricultural pest and thus a herbivore). Unfortunately, the native snails proved tastier and easier to catch - and many species were literally eaten to extinction.

Creature Feature #536: ʻōʻō

The Hawaiian ʻōʻō was a beautiful nectivorous songbird, endemic to the Hawaiian islands. There were four distinct species, occupying separate islands. The largest measured around 30 cm from head to tail. He was generally considered to be related to the Australian honey-eaters and shared a similar diet - drinking the nectar from flowers. Genetic research has since shown them to be distinctly different, and any similiarities a result of convergent evolution, where unrelated species develop similar traits to fill similar niches.

 The arrival of humans on the islands marked the beginning of the end for the ʻōʻō. Birds on Oahu and Hawai'i were hunting extensively for their yellow feathers, which were worn by nobility. Deforestation claimed their land, rats claimed their nestlings, and like many Hawaiian birds, they proved vulnerable to the introduction of bird malaria. The first to become extinct was the Oahu ʻōʻō in 1837, the Bishops ʻōʻō of Molokai following in 1904 and the Hawaiian ʻōʻō hanging on until the last confirmed sighting in 1937. The smallest, the Kaua'i ʻōʻō survived a little longer - mongoose never made it to that island - being declared extinct then rediscovered on several occasions, but surveys in 1987 found no evidence of their continued existence.

The ʻōʻō, like the huia and oh-so-many beautiful, unique birds, is an example how isolated populations can be extremely vulnerable to outside pressures, especially when they have evolved without the addition of natural land predators. Neither New Zealand nor Hawaii had any mammalian predators until humans came and brought with them the rats and mice, mongoose (Hawaii) and mustelids (New Zealand).

Creature Feature #500: Nene

The Nene, or Hawaiian Goose, is the rarest Goose in the world. Found only on the islands of Hawaii, he is a terrestrial Goose, favouring grasslands and lava plains. The Nene was hunted heavily, as well as falling prey to introduced predators such as mongoose. By 1952, only 30 individuals survived. Luckily, he breeds well in captivity and new populations were established from captive-bred birds. Now his population stands at around 2500 birds, although there are concerns of inbreeding.