A large bird, feeding on fruits from Tonga, joins the dodo in a group of giant island pigeons, which were hunted to extinction. The fossils show that Tongoenas burleyi, a newly described genus and species, lived on the Pacific islands for at least 60,000 years, but disappeared within one or two centuries after the arrival of man about 2,850 years ago. The Florida Museum of Natural History talks about the new species, citing research in the journal Zootaxa.
Unlike the dodo and the extinct giant pigeon Viti Levu from Fiji, T. burleyi could fly. The new species developed in the midst of fruit-bearing mango, guava, and cherry trees. This pigeon acted as an important cultivator of the forest, spreading fruit seeds to new locations. The size of a large duck, Tongoenas burleyi, is probably capable of swallowing a fruit the size of a tennis ball.
Some of these trees have large, fleshy fruits, clearly adapted for the large pigeon to swallow the fruit whole and transfer the seeds. Of the fruit-eating pigeons, this bird is the largest and could swallow larger fruits than any other.
David Stedman, lead author of the study, curator of ornithology at the Florida Museum of Natural History
The absence of T. burleyi in the Tonga Islands could threaten the long-term survival of native trees, which depend on the pigeon as a seed carrier.
T. burleyi has provided an important service to nature by transporting seeds to other islands. The pigeon species in Tonga today are too small to eat large fruits, which threatens some of the fruit trees.
When the scientist first discovered the T. burleyi fossils in a cave on the island of Tonga in Eua, he was immediately struck by their size: the bird was about half a meter in length, excluding the tail, and weighed at least five times more than the average city pigeon.
The Colombids family, which includes pigeons, had few predators or competitors before humans reached the Pacific Islands, scientists say. The region lacked primates and predators such as cats, dogs, and weasels, and hawks and owls were absent from many of the islands. For 30-40 million years, birds flourished in this nutrient medium until humans came there.