Fountain Grass and Mongoose

Fountain grass (Pennisetum setaceum) was introduced as a horticultural plant sometime before 1914. It is a popular ornamental grass because of its attractive seeds and low maintenance.

Fountain grass, along with other invasive grasses, have taken over the dry forest habitat previously dominated by wiliwili, māmane, koa, lama, ‘aiea, and other endemic species. The grasses crowd out native species, and promote wildfires. Fountain grass can even grow on steep slopes and create “fire ladders” to spread fire upward to areas of native forest.

The sly small Indian mongoose (Herpestes javanicus) is often found hiding in the tall grass. The sugar industry introduced the mongoose to the Hawaiian Islands in 1883 to control rats. The mongoose is good at preying on rats. However, it doesn’t limit its diet to rats. The mongoose eats native birds, domestic birds, insects, fruits, sea turtle eggs, and almost any small animal it can catch. Many native birds build their nests on the ground and are vulnerable to attack by the mongoose.

The mongoose also reproduces rapidly. A mongoose can produce an average of 36 young in a lifetime. In 1916, 30 years after their introduction, the population of mongoose on Maui became such a problem that a bounty of 10¢ per dead mongoose was offered. (In today’s value, that’s about 5 mongoose for a regular plate lunch.) The mongoose is widespread on Hawai‘i, Maui, Molokai, and O‘ahu. Efforts are ongoing to keep the mongoose from establishing on Kaua‘i, and Lāna‘i.