Humans in Fiji: strangers in paradise 2

Fiji's human interlopers

I've previously written here about how feral animals, introduced into the Fiji islands by humans, devastated many native species, particularly birds and reptiles. The Polynesian rat and domestic pig were brought by the people who discovered Fiji 3,500 years ago. Rats and pigs were a food supply, both during the voyagers' amazing ocean voyages and after they made landfall. In the 19th century, they were joined by the black rat, brown rat, house mouse (accidental introductions) and the dog, cat, goat, mongoose and cane toad (deliberate introductions).

However, in that post I didn't consider how humans themselves changed the environment. What were Fiji's glorious islands like 3,500 years ago? We now know the large, mountainous islands were covered by lush rainforest. The western parts of Viti Levu and Vanua Levu are now areas of dry grassland, and everybody who lives there is sure they were always so. These are the areas where sugar has been grown for more than a century. But scientific analysis of charcoal and pollens found preserved in swamps indicates the grassland is the result of repeated burning by the early human settlers. Humans all over the world burn forest to clear the ground for planting crops or for hunting, usually both. Fijians were no exception.

Polynesian rat

Fiji before humans

In recent years, we've been able to build a picture of what pre-human Fiji was like. The newly-discovered ecosystem had evolved in isolation for many millions of years. Palaeontologists Worthy and Anderson discovered an array of large fauna in several undisturbed limestone caves in Fiji's biggest island, Viti Levu. In prehistoric times, many vertebrates fell into the caves where they died and were eventually buried by falling debris.

Worthy and Anderson identified the following fauna from remains of bones and no doubt, more will be added to this list in future.

• a land crocodile, 3 metres long

• several species of megapode (incubator bird which lay eggs in self-built mounds). The largest outweighed a domestic turkey.

• giant land iguana (1.5 metres long, weighed up to 20 kg)

• giant frog

• large land tortoise

• pigeon (probably flightless) the size of a dodo

Museum display of the extinct Dodo, comparable in size to extinct pigeon in Fiji (Wikimedia Commons)

I first discovered these facts in the ground-breaking book Fiji's Natural Heritage by Paddy Ryan. Dr Ryan, former University of the South Pacific biologist, believes the early Fijian people destroyed all these large land fauna and more, to extinction, while the Polynesian rat wiped out many smaller species of flightless birds, frogs and lizards. The 19th century imports of brown and black rats, goats, mongoose and cane toads have all but finished off more native species of small reptile and ground birds. Goats have destroyed wild habitat.

It is imperative that smaller mountainous islands like Taveuni, where flourishing rainforest still supports ground-nesting birds and small reptiles, are protected with the strongest laws, supported by intensive education. Humans can't bring back what's lost forever, but we can prevent future loss.

Small Indian mongoose in Fiji

I would love to answer any questions about Fiji or my books from readers. Just leave me a message on bmallsopp.com or email me at bernadette@bmallsopp.com.

I look forward to hearing from you!

Bernadette

B.M. Allsopp