Location and Values: Henderson Island is a raised coral atoll in the middle of the South Pacific, the largest of four islands that make up the Pitcairn group. It is uninhabited and remains in remarkably pristine condition due to its very remote location, 5,000 km from the nearest major land mass. Although it supports relatively few species of plants and animals, it is an important site for the scientific study of island biogeography, evolution and natural selection. In particular it has four endemic species of land birds that have evolved on the island, ten endemic taxa of vascular plants, and important breeding colonies of sea birds.
Conservation Status and Prospects. According to IUCN’s Conservation Outlook Assessment (2017) the conservation status of Henderson Island is ‘of significant concern’. The IUCN report notes that the biodiversity values of the island remain very highly threatened by rat predation, affecting seabird populations and other aspects of the island’s ecology. For example, rats are believed to be responsible for a catastrophic decrease in the recorded population of petrels, from an estimated >1 million pairs on the island before the introduction of rats to just 40,000 pairs today. This has a knock-on impact on other ecological processes, as the guano produced by millions of seabirds would have provided a crucial nutrient source for the island’s ecosystems before the arrival of rats. The site is also at risk of new invasive alien species introductions, which could occur as a result of uncontrolled or poorly managed visitation. A further threat is the increasing accumulation of plastic debris that is washed ashore along the island’s beaches, affecting the natural beauty of the island.
UNESCO Official Website
IUCN Conservation Outlook
UNEP-WCMC Site Description