Hidden Colony Doubles Known Numbers of Rare South Pacific Bird

James Owen in England
for National Geographic News

July 15, 2003

One would expect a bird living in the shadow of remote island volcanoes
to lead a somewhat precarious existence. Even so, in 1993 ornithologists
were shocked to discover only around 400 adults separated the Polynesian
megapode (Megapodius pritchardii) from extinction.

In a desperate effort to save the species, eggs from the bird's last remaining colony, on the Tonga island of Niuafo'ou, were taken to a uninhabited speck of land, 20 hours away by boat.

Ten years on, and the experiment has proved a huge success. Much to the surprise of Dick Watling, who recently visited [March 2003] Fonualei in the western South Pacific.

"Others who had been to the island, or learned of its habitats, thought it wouldn't support megapodes, so I wasn't prepared to find them," said the Fiji-based ornithologist, who was forced to swim the last leg of his journey because large boulders prevented him landing by boat. "It was difficult doing the final 50 meters [164 feet]!"

Yet the risks were worth the effort. Before leaving the next morning he had counted enough birds—known locally as the malau—to estimate a total population of between 300 and 500. In effect, the malau's known global population had doubled overnight.

"The news is spectacular," said René Dekker, chairman of the Megapode Specialist Group, a Swiss-based conservation union working on protecting the 22 species of megapodes. "This means the malau occurs on two islands instead of one, and the population seems to have doubled."

Megapodes are found mainly in moist, tropical forests in Australasia and Southeast Asia. They belong to the avian order Galliformes, which includes grouse, partridges, pheasants, and turkeys. What sets megapodes apart from these game birds is their extraordinary breeding behavior.

Buried Eggs

"Megapodes are fascinating," said Dekker. "They are the only birds which don't incubate their eggs by means of body heat, but bury them, like sea turtles, in the soil. The chicks emerge after days of digging, but have no parents to take care of them."

Laid in burrows or under mounds, megapode eggs are incubated by the warmth of the sun, rotting vegetation, or volcanic vents. The main drawback is that few sites are suitable for the job, so eggs tend to get grouped together. This makes them relatively easy for humans and other predators to find.

Ornithologists believe this is why the malau has become so scarce.

Confined to the Kingdom of Tonga, the bird is the most threatened of 22 megapode species. It's classed as "critically endangered" by the World Conservation Union, which means it faces "an extremely high risk of extinction in the wild in the immediate future."

Dekker said: "The malau once lived throughout the Tongan archipelago. But it's been exterminated by Polynesians on all these islands except Niuafo'ou, where a small population managed to survive."

But a study in the early 1990s concluded the Niuafo'ou population was also threatened by human predation. Researchers found that 50 percent of all eggs were taken by islanders, for whom the malau is a traditional food source. Introduced dogs and cats also accounted for significant numbers of birds.

Although it's illegal to collect megapode eggs in Tonga, the central government is 370 miles (600 kilometers) away and the law hard to enforce.

So in 1993, Dieter Rinke, from the Brehm Fund for International Bird Conservation in Germany, decided to ship almost 70 malau eggs and ten chicks to Fonualei.

Dekker said: "This island had to be without men, dogs, cats and rats. Fonualei is also volcanically active, which the birds need for incubating their eggs."

Volcano Threat

But until Watling's visit nobody knew whether the experiment had worked. Now that it has, Fonualei should ensure the malau doesn't disappear in a spectacular explosion.

"Having all the eggs in one basket was a bit dangerous," added Dekker. "Niuafo'ou had its last volcanic eruption about 50 years ago. A major one could easily have wiped out the entire population."

Watling, who represents conservation charity BirdLife International in the region, also believes the new colony should help secure the malau's future.

"There is very little or nothing that needs to be done on Fonualei in terms of development," he said. "In fact, it would be a wonderful bird reserve since it also has the largest colony of sooty terns in Tonga, and perhaps Polynesia-Melanesia as well."

Other birds on the island include boobies, fairy terns, frigate birds, and a good-sized population of friendly ground doves, a species classed as internationally vulnerable. Watling added: "This is a wonderful success story for conservation in a region where conservation is only beginning to emerge from the era of rhetoric and paper parks."

And the success story may not end there. Watling has a new voyage to make—to Late. This is another uninhabited island where malau eggs were left almost a decade ago. As yet, ornithologists aren't sure how the malau eggs have fared.

Watling hopes to find out next year, but Dekker warns: "Landing by boat on Late is very difficult and can only be done in a few parts of the year when the seas are calm."

Maybe things are looking up for the malau, but they're threatening to make Robinson Crusoes of those who go in search of them.