Although rare or absent from some of the islands, where it has suffered from habitat loss and avian malaria, this nectar-loving bird still has a foothold in much of Hawaii. Traditionally prized for its fabulous plumage, which matures
to a brilliant red, the I'iwi's feathers were once collected to make cloaks and headdresses for Hawaiian royalty.

Doug Cheeseman/Still Pictures

Its name, in the Quechua language, means 'vine of the soul'. Traditionally prepared as a brew taken by the forest people as a vision-inducing sacrament, ayahuasca also makes a good medicine, causing intense vomiting and diarrhoea that helps purge the body of tropical parasites.

Dr Morley Read/Science Photo Library

They're not much taller than people, at 2.5 metres, but they're chubbier than Asian elephants - of which, according to new research by WWF and Columbia University, they are a subspecies - and have bigger ears and longer tails. Only about 1,600 of them remain in their home, the northeast tip of Borneo, and they are threatened by poachers and the spread of commercial plantations.

A. Christy Williams/WWF-Canon

The world's largest butterfly, with a 28-centimetre wingspan, lives only in New Guinea's lowland coastal rainforest. But Queen Alexandra's birdwing is rare, and becoming rarer, thanks to insect collectors and to clearing forests for palm oil plantations. It is particularly vulnerable as its larvae depends entirely on one plant - the pipevine, from which it gets a poison that wards off predators.

Francois Gilson/Still Pictures