The Wetlands of the Pitcairn Islands
Used by Permission of Wetlands
PITCAIRN ISLANDS--Introduction (Document prepared, 1992.)
Population: 66 in January 1992 (Population in October
2005: 42 Pitcairners, 8 others.)
The Pitcairn Islands are a group of four
small islands situated between latitudes 23 and 26 degrees South and longitudes
124 and 131 degrees West in the South Pacific Ocean, about 2,000 km southeast
of Tahiti and 1,900 km west of Easter Island. The group comprises Pitcairn Island
(25 degrees 04 minutes South, 130 degrees 06 minutes West) and three uninhabited
islands: Oeno (120 km northwest of Pitcairn), Henderson (200 km east-northeast
of Pitcairn) and Ducie (472 km east of Pitcairn). Pitcairn itself is a high volcanic
island of 450 ha with lava cliffs and rugged hills rising to a peak at 335 m.
Henderson, the largest island in the group with an area of 3,700 ha, is a raised
limestone atoll which rises to 33 m. Oeno (65 ha) and Ducie (70 ha) are both low
coral atolls with maximum elevations of about 4 metres.
The climate is
subtropical, with an average rainfall of about 2,000 mm spread evenly throughout
the year. Henderson is somewhat drier than Pitcairn, with 1,620 mm of rainfall
in 1991/92 compared with 2,170 mm on Pitcairn in the same period. Mean monthly
temperatures range from 24 degrees C in January to 19 degrees C in July. The Southeast
The Pitcairn Islands are a British Crown Colony, with
the British High Commissioner in New Zealand holding the position of Governor.
Most of the 66 inhabitants are direct descendants of the mutineers from H.M.S.
Bounty and their Polynesian consorts, who reached the islands in 1790. In 1856,
the 194 inhabitants were moved to Norfolk Island, off the east coast of Australia,
but by 1864, 43 of the islanders had returned, and Pitcairn has been permanently
settled since then. The local economy is based on subsistence agriculture, the
fertile volcanic soils of Pitcairn producing a wide variety of tropical and subtropical
crops. Some fruit, vegetables and handicrafts are sold to passing ships running
between New Zealand and Panama. A re-afforestation scheme was introduced in 1963
with emphasis on the planting of miro trees (Thespesia populnea) which provide
the wood used in making handicrafts.
The islands are of particular conservation
importance for their endemic plants and invertebrates, endemic land-birds (four
on Henderson Island), globally significant breeding populations of seabirds (especially
gadfly petrels Pterodroma spp.), and non-breeding populations of the threatened
Bristle-thighed Curlew (Numenius tahitiensis). The main interest in the coral
reefs is their isolated and undisturbed location at the geographical limit of
reef growth. The breeding population of Green Turtles (Chelonia mydas) at East
Beach on Henderson Island may also be of international importance.
of Wetland Situation
The Pitcairn Islands have very few freshwater
habitats. Pitcairn itself has some permanent streams as well as a number of intermittent
streams, but there do not appear to be any permanent freshwater ponds or marshy
habitats. No fresh water is known to occur on the other three islands except for
cave drips on Henderson and freshwater lenses on Oeno. The only other wetland
habitats in the islands are coral reefs, reef flats and beaches. Coral reefs are
well developed on Oeno and Ducie and surround most of Henderson, but are poorly
developed around Pitcairn (Hepburn et al., 1992). There are three large discrete
coral sand beaches on Henderson.
Only seven species of waterbirds are known
from the islands. The Pacific Reef-Heron (Egretta sacra) has been recorded on
Henderson and Oeno. The flightless Henderson Island Crake (Porzana (Nesophylax)
atra) is confined to Henderson where it remains common, and the Spotless Crake
(Porzana tabuensis) has been reported from Oeno. Wandering Tattlers (Heteroscelus
incanus) and Bristle-thighed Curlews (Numenius tahitiensis) are fairly common
non-breeding visitors to the beaches and reef flats during the austral summer,
and the Pacific Golden Plover (Pluvialis fulva) and Sanderling (Calidris alba)
have been recorded (Williams, 1960; Pratt et al., 1987; M. de L. Brooke, pers.
comm.). The relatively large numbers of Bristle-thighed Curlews (a threatened
species) on Henderson and Oeno are of international significance. Green Turtles
(Chelonia mydas) nest on the largest beach on Henderson.
No protected areas
have been established in the islands, but the extreme isolation of Henderson,
Oeno and Ducie affords these uninhabited islands a considerable degree of protection.
Henderson Island was inscribed as a World Heritage Site under the Unesco World
Heritage Convention in 1988. Hepburn et al. (1992) have recently discussed the
application of the Convention of Wetlands of International Importance especially
as Waterfowl Habitat (the Ramsar Convention) to the Pitcairn Islands, and have
concluded that the two low-lying coral atolls of Oeno and Ducie and the beaches
and inshore reefs of Henderson would be suitable for designation as Wetlands of
International Importance under the terms of the Convention.
Despite a substantial number of visits by scientists and naturalists
to one or more of the Pitcairn Islands in the last century, the island remain
relatively poorly known. A major independent multi-disciplinary expedition, based
on Henderson Island from January 1991 to March 1992, has gathered a considerable
amount of information on the current and historical ecology of Henderson and on
the other islands in the group. Thirty-four individuals from seven countries participated
in this expedition . Much of the information has yet to be analyzed and presented,
but early results from the expedition (Brooke et al., 1991; Weisler et al., 1991)
provide a substantially improved basis for assessing the conservation value of
the islands’ biota (Hepburn et al., 1992). One of the objectives of the
Pitcairn Islands Scientific Expedition was to assess the potential for designation
of Oeno and Ducie atolls as Wetlands of International Importance under the terms
of the Ramsar Convention.
Wetlands Area Legislation
legislation in the Pitcairn Islands has recently been reviewed by Hepburn et al.,
(1992). There is no specific conservation policy for the islands, and there appears
to be no specific legislation covering the protection of sites for conservation
purposes. The Ordinances (Local Government Regulations, 1971) cover wildlife protection
and fisheries management. The legislation generally prohibits the killing of wild
birds or taking of their eggs, or, subject to the authority of the Wild Bird Protection
Committee, controls the extent to which certain prescribed species may be exploited.
An amendment in 1982 adds species which are protected (three whales, three seabirds
and two turtles), and sets conditions under which they may be captured, killed
or harassed. This amendment also extends protection to migratory species as a
means of implementation the Convention on the Conservation of Migratory Species
of Wild Animals (the Bonn Convention) within the Pitcairn Islands.
Pitcairn Islands are included in the UK ratification of the Ramsar Convention.
Wetland Area Administration
The Pitcairn Islands Council has ultimate
responsibility for the implementation of any management decisions which might
affect natural ecosystems including wetlands.
Pitcairn Islands Council - Wild Bird Protection Committee.
Site descriptions compiled from information provided by
J.R. Setterfield (Office of the Governor of Pitcairn Island), M. de L. Brooke
and I. Hepburn.
Click for details:
[Oeno Atoll] [Henderson
Island] [Ducie Atoll] [Wetlands
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Atoll] [Henderson Island] [Ducie
Atoll] [Wetlands Introduction]