LIHUE — A rapid assessment team flew to Lehua Island Tuesday after checks of motion-detecting field cameras showed the presence of two rats.
“While we are clearly disappointed to see evidence of two rats on the island, we are very lucky our partners were able to detect them,” Department of Land and Natural Resources Chair Suzanne Case said. “We knew from the beginning there was the possibility that a few rats could linger. Now it’s important to address this.”
Human observations using monitoring devices last month did not detect any sign of rodents. Post-project monitoring followed last August and September’s trio of applications of a rodenticide aimed at ridding the island of the introduced, invasive, harmful Pacific rats to protect native seabirds.
Dr. Andre Raine of Kauai Endangered Seabird Recovery Project noted last month that monitoring teams conducting investigations throughout the fall, using numerous detection devices, had not detected any visible evidence of rats.
“These cameras are highly effective critical early warning tools for locating any remaining rats,” he said. “They did their job and we can now target areas for a swift response to hopefully deal with whatever rats remain on the islet. 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.”
Mele Khalsa of Island Conservation, the non-profit contractor experts helping the Lehua rat eradication project, is leading the rapid assessment team on Lehua. The team is comprised of experts from Island Conservation, the DLNR Division of Forestry and Wildlife’s non-native avian predator control team, and the KESRP.
“Our primary goal was to assess the distribution and abundance of any rats that may be on Lehua. These data are critical to inform any management steps we need to take,” she said. “After seeing these two rats on camera, we collected, immediately reviewed, and noted locations of any additional images the cameras may have picked up.”
Camera cards were reviewed after Christmas and revealed images of two rats. KESRP staff immediately reported the photos of two rodents, of unknown species, to DLNR and IC.
After reviewing camera cards on Tuesday, no additional rat images were found. The team placed 134 monitoring devices on Lehua, including three different types of traps. Some of the devices will be left in place; others will be re-established when monitoring teams return to the island.
The team will meet with project managers to assess a suite of additional treatment options including localized hand-applied rodenticide application.
The teams uses five different types of detection devices including tracking tunnels, that use ink pads to detect footprints; wax chew blocks; live, snap and GoodNature traps; camera traps and bait piles.
Monitoring protocols in place for the eradication program call for Island Conservation monitoring teams to travel to the remote island every other month.
This week’s rapid response is in advance of a previously planned bi-monthly monitoring trip in mid-January.
Other than the two rodents caught on camera, none of the devices have detected rat presence since the rodenticide applications began.
The invasive Pacific rat is a voracious predator on the eggs, chicks and even adult birds that currently breed and nest on remote Lehua.