Skip to main content
Skip to navigation

April 7, 2011 Volume 32, No. 26

Avian dream: Bringing an endangered species back from the brink


AVIAN ATTRITION Dylan Kesler, a researcher and assistant professor in fisheries and wildlife at MU's School of Natural Resources, is trying to stop the demise of the Tuamotu Kingfisher. The Tuamotu once thrived on several islands in French Polynesia. But, according to a 2008 census, the species has been reduced to a single population of about 125 birds on Niau Atoll, a small sprig of coral in the South Pacific. Kesler's team is working with farmers to create a hospitable habitat, teaching atoll residents to appreciate the birds' part of the ecosystem and relocating some birds to a second island home. "There is no other bird like this on the planet,” Kesler said. Photo courtesy of Dylan Kesler


“Translocation” could help save the Tuamotu Kingfisher

The Tuamotu Kingfisher is a Pacific island bird with a cream-colored head, blue and green feathers, and a white underbelly. During courtship, the male will bring a lizard to a prospective mate, banging the reptile against a tree in a show of affection.

A 2008 census revealed a single population of about 125 Tuamotu Kingfishers, on a small sprig of coral in the South Pacific. That’s down from approximately 500 birds in 1974, making the Tuamotu one of the world’s most endangered species. At one time, only 39 birds could be located.

A University of Missouri researcher is trying to stop the birds’ demise. In addition to studying the causes of the Tuamotu’s decline, Dylan Kesler, assistant professor in fisheries and wildlife at MU’s School of Natural Resources in the College of Agriculture, Food and Natural Resources, is working with farmers to create a hospitable habitat, teaching local resident to appreciate the birds’ role in the ecosystem and relocating some birds to a second island home.

“If we lose these birds, we lose 50,000 years of uniqueness and evolution” Kesler said. “Because it has lived in isolation for a very long time, it’s unlike any other bird. There is no other bird like this on the planet.”

Centuries ago, the Tuamotu Kingfisher thrived on several South Pacific islands in what is now French Polynesia. Today, it’s only found on Niau Atoll, a ten-square-mile dot surrounded by deep blue ocean.

The reason for the birds’ decline is uncertain. Kesler thinks rats that migrated from sailing ships became predators in a competition for food. Feral cats also prowl the island, feasting on young birds. Destructive typhoons that destroyed nesting trees haven’t helped, either.

Because of its small population and its single island habitat, the Tuamotu has been listed as “critically endangered” by the International Union for Conservation of Nature. A typhoon, changes in climate or land-management practice could deliver the coup de grâce for this last population.

For five years, Kesler and his team researched kingfisher movements, as well as the species’ breeding biology, nesting behavior and population demography. The entire island was thoroughly surveyed four times for the birds. The team captured 60 kingfishers and radio-tagged them. The scientists followed movements for weeks before the specially designed transmitters dropped off. The team also broadcast kingfisher calls and pinpointed the responses.

Kesler discovered the birds were doing poorly in the atoll’s forest – palm trees growing out of the jagged coral – because the dense foliage provides cover for the lizards and insects that kingfishers eat. This cover also prevents the birds from using their unique “wait-and-drop” hunting technique: the kingfisher watches its prey from a perch a few feet off the ground before pouncing on it from above.

Researchers found that, compared to the birds in the forest, the Tuamotu was thriving in the atoll’s coconut groves, where the lowest limbs of the sparse trees are about five feet off the ground. To kill rats, coconut farmers burned the grove’s underbrush, clearing additional hunting space.

“Interestingly, the twist on these birds seems to be that agricultural habitat is key to their survival,” Kesler said. “The birds use agriculture more than any other habitat type, and they seem to be unique among endangered species that benefit from anthropogenic landscapes.”

Kesler’s effort to save the Tuamotu Kingfisher has three elements – educating Niau’s coconut farmers to provide a hospitable habitat; getting the local population excited about their unique bird species; and relocating some of the birds to another suitable island.

The education program started in Niau’s primary school, where students were as excited about the project as the research team. “These birds are part of their history,” Kesler said, “and no one is more excited about their survival as the island residents.”

Farmers were encouraged to leave a few dead trees for kingfishers to build nests and to wrap metal bands around the trees to thwart climbing cats and rats.

Kesler and his team evaluated three promising islands to host a second “rescue” population: the Gambier Islands; the high island of Makatea; and the atoll islands of Anaa.

The Gambier Islands contained too many invasive species and Makatea was just beginning to recover from a century of phosphate extraction. The team visited Anaa’s larger islands in March 2010 and found habitats similar to those on Niau, with many of the same native plant species, stretches of virgin forest and plenty of coconut groves.

Once the researchers confirmed that Anaa’s coconut groves had abundant hunting perches and exposed ground — as well as a thriving lizard population — they tested their ability to move the Tuamotu from one island to another. Using nets, they captured birds on one side of Niau and released them in an area without kingfishers. The team then radio-tracked movements of the birds to ensure they survived the test relocation.

“The translocation experiment was a resounding success,” Kesler said. “Both trans-located and control birds weathered the experiment well and several found new mates within days. These observations are the key for designing the larger inter-island relocation that we hope to undertake in the next few years.”

Because there are few documented cases of the successful relocation of bird species, Kesler’s experiments are of great interest to researchers in several disciplines. His discoveries made the cover of The Auk, a journal of the American Ornithologists Union, and a feature story on Kelser’s work was just published in the Journal of Wildlife Management.

Moving birds from Niau to Anaa may represent the best hope to save the Tuamotu Kingfisher.

“As we become more committed to saving species, translocation will become a more important tool,” Kesler said. “The science to move animals is just being developed.”

“Unfortunately, even with all our work to date, the Tuamotu Kingfisher population on Niau is still crashing,” he continued. “We’re seeing some turnover, but each year when we return, there are more empty territories and the population decreases. At this rate, these birds will be gone within our lifetimes.”

    — Randy Mertens