Lehua Island Rat Population Study Planned

DLNR logo/Maui Now background image.

By Maui Now Staff

A new study of the introduced population of rats to Lehua Island is being launched next week as state and partner agencies attempt to determine what actions, if any, might be needed to protect the island’s native plants and animals.

Lehua is located just three-fourths of a mile north of Niʻihau, and has a population of invasive Pacific rats.  The island is also home to many seabird species and native plants, including threatened or endangered species.

State officials say the island is owned by the US Coast Guard, and is protected and managed as a seabird sanctuary by the Division of Forestry and Wildlife.

Officials with the state Department of Land and Natural Resources say the rats at Lehua are known to prey on ground nesting birds, eggs, and chicks.  They also eat the seeds, bark, leaves, and new shoots of plants.

The non-profit Island Conservation group and wildlife personnel will join interested stakeholders in conducting the two-week study from Sept. 14 to 28, 2015.

State officials say the study will involve non-toxic cereal-based rodent pellets applied to the island from a hopper attached to a helicopter. Authorities say the rat pellets contain a non-toxic dye that will allow the biologists to determine which animals eat the pellets.

Following the application, surveyors will determine the quantity of pellets consumed in given locations over time. Authorities say this will allow for estimates of the rat population to be made within the survey area.