Tokyo: A new island emerging off the coast of Japan offers scientists a rare opportunity to study how life begins to colonise barren land - helped by rotting bird poo and hatchling vomit.

Researchers say bird waste will be the secret ingredient to kick-start Mother Nature's grand experiment on a still-active volcano that only poked its head above the waves in November 2013.

The volcano that formed Nishinoshima island is still active. Credit:AFP

That speck of land, 1000 kilometres south of Tokyo, has grown to engulf its once larger neighbour, Nishinoshima, a part of Japan's Ogasawara island chain known for the wealth and variety of its ecosystem.

The new Nishinoshima, a respectable 2.46 square kilometres, the Japan Coast Guard said in February, is almost all bare rock, formed from cooling lava.