Bringing a Bird Back From the Brink

A SNR researcher works to save one of the world's most endangered avians

Kingfisher TeamKesler's team was nothing if not eclectic, including residents of Niau, cooperators from the Tahiti Ornithological Society, graduate students from Dr. Eric Vidal’s invasive species ecology laboratory at Université Paul Cézanne Bâtiment Villemin, a bird expert from Disney's Animal Kingdom, conservation enthusiasts from the Pacific Islands Conservation Research Association, and graduate students in avian conservation from MU.

The Tuamotu Kingfisher is a Pacific island bird with a cream-colored head, blue and green feathers, and a white underbelly. It sings with its mate. Males, during courtship, bring lizards to their girlfriends, banging the reptiles against trees in shows of affection.

Bringing a Bird Back From the Brink

This kingfisher is one of the world’s most endangered species. A 2008 census revealed only one population with approximately 125 individuals alive – down from approximately 500 birds in 1974. At one time, only 39 birds could be located.

University of Missouri researcher is trying to stop the birds’ extinction by studying the causes of its decline, working with farmers to create a hospitable habitat, teaching kids to appreciate the birds’ part of the ecosystem, and by relocating some birds to a second island home.

“If we lose these birds, we lose 50,000 years of uniqueness and evolution” said Dylan Kesler, assistant professor in fisheries and wildlife at MU’s School of Natural Resources in the College of Agriculture, Food and Natural Resources. “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.”

A Species Reduced to One Island

Centuries ago, the Tuamotu Kingfisher thrived on several South Pacific islands in what is now French Polynesia. Today, it lives only on one small sprig of coral, Niau Atoll, a ten-square-mile dot surrounded by deep blue ocean.

The reason for the birds’ decline is uncertain. Keslerthinks rats jumped off sailing ships and became a predator species that also competed for food. Feral cats also prowl the island and eat young birds. Destructive typhoons that destroyed nesting trees didn’t help, either.

This species has been listed as Critically Endangered by the International Union for Conservation of Nature because of its small population and its single island habitat. One typhoon, change in climate or land management practice could deliver the coup de grâce for this last population.

Learning About Kingfishers

For five years, Kesler and team researched kingfisher movements, its critical resources, breeding biology, nesting behavior and population demography.

The entire island was thoroughly surveyed four times for the birds. Kesler and team captured 60 kingfishers and radio-tagged them. The scientists followed movements for weeks before the specially-designed transmitters dropped off. The team also broadcasted kingfisher calls through speakers and pinpointed the responses.

Kesler discovered the birds were doing poorly in Niau’s atoll forest – palm trees growing out of the jagged coral – because the dense foliage provides cover for the lizards and insects that the kingfishers eat. This cover also prevents the birds from using their unique hunting technique of pouncing on prey. Here, the kingfisher perches on a limb over a clear area. When a meal walks by, the kingfisher falls on it – something researchers termed a wait-and-drop hunting attack.

The birds that were thriving weren’t living in atoll forests, but in farmers’ coconut groves. Here, the lowest limbs of the sparse trees are about five feet off the ground, the perfect plunge for a lizard-hungry kingfisher.

To kill rats, farmers burned the grove’s underbrush, which provided kingfishers a clear hunting space as well as fewer rats.

“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.

Kids and Kingfishers

Kesler’s effort to save the Tuamotu Kingfisher was broken into three broad plans – 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. Should the Niau population go extinct, birds on the second island could continue.

The education program started in Niau’s primary school. “The students were as excited about the project as we were,” Kesler commented. “These birds are part of their history 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 in. To stop climbing cats and rats, land owners were taught to wrap metal bands around the trees.

Translocating a Rescue Population

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

The Gambier Islands contained too many invasive species and Makatea is just beginning to recover from a century of phosphate extraction.

In March 2010, the team visited Anaa’s larger islands. “The habitats on these atolls are similar to those on Niau, with many of the same native plant species, stretches of forest that remain un-impacted by human activities, and expanses of coconut plantations,” Kesler said.

Coconut groves there were confirmed to have abundant hunting perches and exposed ground for good lizard plunging. The team counted reptiles to make sure that there would be enough for relocated Tuamotu Kingfishers to eat.

The team also tested their ability to move birds from one island to another. Using nets, they captured birds on one side of Niau and released them in an area without kingfishers. Interestingly, these birds continued to use coconut agriculture. “Perhaps the prehistoric primary habitat of the kingfishers is now entirely absent and the birds are making the best of a bad situation,” Kesler said.

The team radio-tracked tracked movements of the birds to ensure they survived their test relocation. “The translocation experiment was a resounding success,” Kesler commented. “Both translocated 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.”

Not much science has been documented on the techniques and success of relocating bird species, making Kesler’s experiments of great interest in several disciplines. His discoveries made the cover of The Auk, a journal of the American Ornithologists Union, and a feature story was just published in theJournal of Wildlife Management.

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

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

“Unfortunately, even with all our work to date, the Tuamotu Kingfisher population on Niau is still crashing,” Kesler said. “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.”

Leave a Reply

Your email address will not be published. Required fields are marked *