World's rarest bird pictures: A dance in search of a partner

Birds don't only fly, they run, they jump, they dive, they swim, and occasionally, they even dance – as this red-crowned crane is doing, in this remarkable image taken in China.

Cranes dance when looking for a mate, as part of an elaborate courtship ritual, and the sight is one of the most notable spectacles of the natural world. The image is part of a series of prize-winning pictures of the world's rarest birds, shot in an international competition launched last year to photograph the 556 most threatened bird species on earth.

The results will be published next year by the ethical publishing company WILDGuides, and profits from sales will go to BirdLife International's Preventing Extinctions Programme to help support conservation projects worldwide.

Many of the species are not only rare and difficult to photograph – they tend to have retreated to remote places – but are among the most strikingly beautiful of birds. The red-crowned crane, Grus japonensis, captured here by Huajin Sun, is one example.

Breeding in China and wintering in Japan, it is an iconic bird in the culture of both nations, featuring prominently in their art and poetry. The world population now numbers only 1,700 mature birds and is continuing to decrease, due to the loss and degradation of wetlands through conversion to agriculture and industrial development.