Enormous Fruit-Eating Pigeons Hunted to Extinction

These canopy-dwelling beauties thrived in the Pacific islands ... until humans came along.

Beautiful illustration of a large, colorful pigeon
Illustration of Tongoenas burleyi.

 Danielle Byerley

When David Steadman, curator of ornithology at the Florida Museum of Natural History, first came across the fossils of a pigeon in a cave on the Tongan island of 'Eua, he was struck by the size. At 20 inches long, excluding the tail, the mystery pigeon would have weighed at least five times as much as the average city pigeon.

"I said, 'Oh my God, I've never seen a pigeon that big,'" Steadman said. "It was clearly something different."

The fossils would reveal that the newly discovered genus and species, Tongoenas burleyi, was as big as a large duck and lived in the canopy, according to a paper describing the find. It co-evolved with mango, guava, and chinaberry trees, whose tennis-ball-sized fruits served as sustenance. The birds would have acted as an essential forest cultivator by spreading seeds far and wide, notes the Florida Museum.

"Some of these trees have big, fleshy fruit, clearly adapted for a big pigeon to gulp whole and pass the seeds," Steadman said. "Of the fruit-eating pigeons, this bird is the largest and could have gulped bigger canopy fruit than any others. It takes co-evolution to the extreme."

Sadly, T. burleyi went the way of another giant island pigeon – the dodo – both of which were hunted to extinction.

As it turns out, pigeons and doves once had the lay of the land in the Pacific islands. With neither primates nor carnivores, birds flourished in this environment and diversified for 30 million years or so.

In the case of T. burleyi, they lived in the islands for at least 60,000 years. Then the humans came, and in a century or two, had killed every last one of the prodigious pigeons.

With T. burleyi gone from Tonga, the long-term survival of trees that partnered with the pigeon may be threatened, said study co-author Oona Takano, a doctoral student at the University of New Mexico.

"T. burleyi provided an important service by moving seeds to other islands," said Takano, who was previously a research assistant at the Florida Museum. "The pigeon species on Tonga today are too small to eat large fruits, which imperils certain fruit trees."

The idea of a large, duck-sized flying pigeon may send shudders to anyone spooked by city pigeons. But Columbidae, the family that includes pigeons and doves, includes around 350 species in myriad shapes and sizes – and includes some of the world's most beautiful birds. (For the record, this writer is on Team City Pigeon.)

The Pacific islands are a global hotspot for pigeon and dove diversity, with more than 90 species calling the region home. Members run the gamut from "fruit doves as light as a handful of raisins to the turkey-sized, ground-dwelling crowned pigeon of New Guinea," explains the Florida Museum. But the number and distribution of birds in the area is a shadow of what it once was, Steadman said. Tonga's remaining species of pigeons and doves represent less than half of the islands' historic diversity.

"This is another example of how looking at the modern fauna doesn't yield a complete picture of a region's diversity," he said. A diversity which once included beautiful, giant, fruit-eating pigeons that worked in concert with the trees.