Lehua Island stays free of dreaded rats

Rats are nowhere to be found on tiny Lehua Island four months after the conclusion of an eradication project.

But the restoration project partners monitoring the ecosystem recovery on the 284-acre island off of Niihau say they won’t declare the eradication effort a complete success until September.

So far, though, they’re encouraged by what they are seeing.

For decades the invasive rats had attacked native seabirds on the island, eating their eggs and chicks. Then the Department of Land and Natural Resources stepped in to apply three rounds of rodenticide beginning in August in an effort to create a predator-free sanctuary for endangered and threatened seabirds. Diphacinone in cylindrical pellets were spread throughout Lehua from a hanging bucket on a helicopter.

“While we conducted our monitoring work we’d been looking for any sign of rat predation and rats,”Andre Raine, of the Kauai Endangered Seabird Recovery Project (KESRP), said Monday. “So far, we’ve seen no signs of rats anywhere on the island, which is a stark difference from trips before the rat eradication work began.”

Raine’s team spent two days last week surveying an albatross colony on the steep cliffs of the north side of the island. Raine said his team did a thorough survey of the entire area, counting nesting Laysan and black-footed albatrosses and pinpointing each nest’s location with GPS.

“This year we have lots of albatross out here, which is great — about 145,” he said.

This was the second monitoring trip by the KESRP team since the last of three aerial applications of rodenticide in September. Raine and other scientists from Island Conservation and DLNR who have conducted separate excursions all report no signs of rats.

“If the rats are gone, we should see a lot more seabirds out here — populations increasing rapidly as more and more chicks fledge instead of being eaten by rats,” Raine said. “Lehua can hold a hell of a lot more birds than are currently here. So we’d expect to see huge increases in population sizes and hopefully new species appearing.”