Stephen’s lorikeet  (Vini stepheni)

Stephen’s lorikeet is considered vulnerable to extinction because it has such a restricted range, where it is at risk from the accidental introduction of alien species. Fortunately, this bird appears to have adapted well to the presence of the only introduced predator on Henderson Island to date, the Pacific rat (Rattus exulans) (4). However, the introduction of a more aggressive predator, such as black rats (Rattus rattus), could be devastating and introduced diseases such as avian malaria and pox pose another potential threat (2) (4). Additionally, the introduction of exotic plant species could have a serious impact on native vegetation and diminish essential feeding and nesting habitat for this species (4). As long as no human settlement on the island is attempted, Stephen’s lorikeet should remain fairly secure, but the island’s vulnerability was exposed in 1982-1983 when a millionaire sought to make it his home (2) (5).

Safeguarding Stephen’s lorikeet appears to rely on ensuring the integrity of Henderson Island (5) and, in 1988, the uninhabited island was designated a World Heritage Site (4). It has been advocated that further research into the impact the Pacific rat has on the bird should be conducted and, potentially, rat eradication should be considered (4) (5). The possibility of rat eradication has been investigated and deemed feasible but is thought to be difficult because of the island’s isolation (4).