Scientists battle to save bird from introduced snakes

The Guam kingfisher, a species almost wiped out by tree snakes, is being returned to the wild and, eventually, to its Pacific island home, reports Robin McKie, of The Observer.

As arks go, the shipping container that has been placed inside Sedgwick County Zoo, in Wichita, Kansas, looks an unlikely vehicle for saving species.

Nevertheless, work there is expected to play a key role in undoing one of the world’s worst conservation disasters: the accidental introduction of brown tree snakes to the Pacific island of Guam.

The snakes’ arrival, at the end of World War 2, eventually wiped out huge numbers of indigenous birds, mammals, and lizards including the Guam kingfisher, the Guam rail, and the Guam flycatcher.

Now British conservationists, working with Guam and US colleagues, are preparing to return one of the most colourful of these lost species, the kingfisher — also known as the Sihek — to the wild and are using the container at the zoo as a quarantine unit for rearing fledglings.

"We now have four birds that have been hatched from eggs collected from other zoos in the US and we expect to have a total of nine by next summer," Claire McSweeney, a Whipsnade Zoo conservationist who is helping staff from the Smithsonian Conservation Biology Institute and from Sedgwick County Zoo on the project, said.

"We will then return them to the wild, and hope to follow up with a similar annual number for the next few years, and so establish a self-sustaining wild population."

The arrival of the brown tree snake had an initially slow impact on Guam wildlife and it was not until the 1970s and ’80s that increasingly alarmed conservationists realised they were now causing widespread deaths of native species. The snakes are expert climbers that spend most of their day on high branches and eat birds, their eggs, and small mammals — with devastating consequences.

The island’s kingfisher population was almost wiped out when the last 29 were captured and sent to collections in the US where they have been bred, increasing their captive population to about 140 in zoos across the nation and also in Guam.

Eggs from these collections are now being sent to Sedgwick to hatch and grow young birds that will be returned to the wild next year.

It is the job of McSweeney and colleagues to nurse the eggs and ensure they hatch successfully.

"Given that a kingfisher egg is not much bigger than a marble that can be a tricky business, but we are succeeding and should have nine or so hatchlings ready to go back to the wild by next year," she said.

"We will be monitoring them round the clock to make sure they are healthy, disease-free and are ready to be returned to the wild."

The birds will not go back to Guam, however. The island is still home to more than 2 million brown tree snakes. Instead, conservationists plan to introduce the birds to a new wilderness home: on Palmyra Atoll, almost 6000km from Guam.

"Palmyra is predator-free and its rainforest can provide nesting materials and food for the birds," said John Ewen, a conservation biologist at the Zoological Society of London and a member of the birds’ recovery team.

The Guam kingfisher, unlike its British counterpart, does not eat fish but will turn to creatures including insects and lizards as part of its diet.

"The hope is that the birds will thrive in Palmyra and establish a breeding population there," Ewen said.

"After that, we will have a wild population to send birds back to Guam — once its snake problem has been resolved." — Guardian News and Media