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A specimen of Guam Kingfisher at the Philadelphia Zoo. Credit: Josep del Hoyo/IBC.

A bird that has been declared extinct in the wild for more than 30 years could see a return to its natural habitat on the Pacific island of Guam, thanks to the work of a University of Tennessee, Knoxville, researcher.

The US Department of Defense has granted Christy Leppanen, a research assistant professor in UT’s Department of Ecology and Evolutionary Biology, a $100,000 award to research the possibility of reintroducing the Guam kingfisher into the wild.

The small bird, which has a maximum recorded weight of just over two ounces, was observed in the wild for the last time in 1988. The kingfisher population plummeted after brown tree snakes were introduced to Guam around the time of World War II. There are currently about 140 Guam kingfishers alive in the world, which all live in captivity on Guam and the mainland United States, under the care of conservationists and scientists with the hope that someday they can be returned to their natural habitats.

“Captivity is not a long-term solution because captive breeding selects for birds that do well in captivity and not necessarily in the wild,” Leppanen explains. “Waiting too long might reduce the likelihood that birds will thrive again in the wild.”

There are currently no known means to eradicate the brown tree snakes from the 212-square-mile island, so scientists are testing methods—such as poisoning by acetaminophen—to reduce their numbers instead. But snakes are not the only threat the kingfisher will have to overcome to successfully go back home: they might also have to deal with habitat degradation, for example.

Leppanen’s research will evaluate future plans of reintroduction by analyzing the successes and failures of past attempts, paying particular attention to the possible impacts of snake population reductions.

“By reducing the number of snakes, rodent populations might thrive instead, and they are also known predators of birds and other native species on the island. There is so much we need to consider,” she said.

Students can participate in Leppanen’s research by enrolling in a special conservation management course that will be offered during the spring 2020 semester.


Andrea Schneibel (, 865-974-3993)