A rapid assessment team was deployed to Lehua Island Tuesday after motion-detecting field cameras showed the presence of two rats on the island.
The state Department of Land and Natural Resources said in a press release this morning that it sent its non-avian predator control team to the tiny island off of Niihau, along with experts from Island Conservation and the Kaua‘i Endangered Seabird Recovery Project (KESRP).
Last month, human observers using a variety of other monitoring devices detected no sign of rodents after a trio of aerial rodenticides were dropped last August and September on the island in an effort to eradicate invasive, Pacific rats harmful to native seabirds.
After Christmas Day, Seabird Recovery staff reviewed camera cards which had been deployed for a research project and found images of the two rats, which are of unknown species. The images were captured between late October and December. The staff immediately reported the rat sightings to DLNR and Island Conservation.
The team, led by Mele Khalsa of Island Conservation, went to the island on Tuesday for further investigation, and returned this morning, said DLNR spokesman Dan Dennison. They did not catch the two rats, but will return again for a regular monitoring trip on Jan. 16.
No further rat images were found from camera cards reviewed on Tuesday from a total of 134 monitoring devices placed on Lehua, nor were any additional rats trapped, according to DLNR. Some of the devices will be left in place; others will be re-established when monitoring teams return to the island.
Andrew Raine of Seabird Recovery said the cameras are highly effective, early warning tools for detecting any remaining rats.
“They did their job and we can now target areas for a swift response to hopefully deal with whatever rats remain on the isle,” he said. “As we’ve said before, we cannot say the rats are truly gone until the island has been given the all clear for an entire year.”
The aerial drop of the rodenticide diphacinone — in cylinder-shaped pellets — last year sparked community concerns over whether it would impact marine life and environment, and was at one point suspected as the unknown cause of death for five, beached pilot whales on Kauai. DLNR said lab results ruled out rat poison as the cause of the whales’ death.