Predation by the Ship Rat Rattus rattus on Lord Howe Island was listed as a KEY THREATENING PROCESS on Schedule 3 of the Threatened Species Conservation Act 1995 [12 May 2000].
Rattus rattus (Linneaus, 1758), Ship Rat (also known as Black Rat, Roof Rat or Alexandrine Rat) was introduced accidentally to Lord Howe Island in 1918 from a ship grounding. The population of Rattus rattus increased dramatically soon after establishment, and is now distributed widely in terrestrial habitats on the Island.
On Lord Howe Island, Rattus rattus has been implicated in the decline and extinction of five species of birds, the Vinous-tinted Thrush, Robust silver-eye, Lord Howe Island Warbler, Lord Howe Starling and Lord Howe Fantail. Rattus rattus has been implicated in the extinction of two large-sized land snails that lived in the southern mountains of Lord Howe Island, a subspecies of Placostylus bivaricosus and an endemic genus and species Epiglypta howinsulae. The extant and endangered land snail Placostylus bivaricosus bivaricosus is at risk from rat predation, as is the large land snail Gudeoconcha sophiae. Rattus rattus has been further implicated in the extinction of the Lord Howe Island Phasmid Drycocelus australis from the main island, although this endangered species occurs on Balls Pyramid where rats are absent. Both Drycocelus australis and Placostylus bivaricosus are listed as endangered species on Part 1 of Schedule 1 of the Threatened Species Conservation Act.
Rattus rattus is known to damage the vegetative parts of several species of plants on Lord Howe Island and to deplete seed yields of the palms Howea forsteriana and Lepidorrhachis mooreana and other species.
this page
