Rabbits, Lisianski Island, Hawaii

(Clapp and Wirtz 1975)

Lisianski is a low, coral sand island, about 200 ha in area, located about 1600 km northwest of Oahu. In the early nineteenth century, it was described as having a few patches of coarse grass and shrubs (the species not named), abundant elephant seals and green turtles, and teeming seabird rookeries. Between 1904 and 1909, the island was occupied several times by Japanese

landing parties, who killed several hundred thousand seabirds for sale of feathers to the French millinery trade. In 1909, Theodore Roosevelt declared the island a bird sanctuary. When the Japanese left, they did not take their domestic rabbits. By 1914, the rabbits had eaten all the vegetation on the island except for some tobacco plants near the abandoned houses and two vines of an Ipomoea sp., perhaps I. pes-caprae , the pantropical beach morning glory; most of the rabbits had starved to death. By 1916, all the rabbits were dead and there were no traces of plant life except some algae.

A scientific expedition in 1923 found four plant species on Lisianski: Eragrostis variabilis and Nama sandwicensis , which are Hawaiian Island endemics that are probably bird dispersed, and Portulaca lutea and Sesuvium portulacatrum , which are pantropical, sea-dispersed beach plants. They also found an unidentified Ipomoea seed and planted Barringtonia asiatica , an Indo-Pacific beach tree, which did not survive. The vegetation in 1923 was restricted to tiny areas. By 1943, much of the island had sparse vegetation, and thickets of Scaevola taccada had developed along some beaches. This Scaevola is a wide-ranging Indo-Pacific seashore shrub, dispersed by both ocean currents and birds. By 1969, the vegetation was thick and included 13 species. Two of these had been deliberately planted: Casuarina equisetifolia and Chenopodium oahuense .