Protected Areas and World Heritage Programme

NAME McKean Island Wildlife Sanctuary

LOCATION 3^o35'S, 174^o02'W; the most westerly of the Phoenix Islands, about 280 km west-southwest of Kanton Island and 125 km north-northwest of Nikumaroro.

AREA 57 ha.

ALTITUDE Sea level to 5 m on the northern beach crest.

OVERVIEW A low coral island with a central landlocked supersaline lagoon, of considerable interest for its diverse and relatively undisturbed plant communities and large breeding colonies of seabirds.

PHYSICAL FEATURES McKean Island is a flat, sand and coral island approximately circular in shape, with a diameter of some 800 m. The beach is largely composed of reef rock and coral rubble, and rises sharply to a circumferential crest within which the land is concave. The interior basin has been further depressed by extensive phosphate workings during the 19th century. There is no standing surface fresh water on the island, nor any evidence of a freshwater lens. A small, shallow, landlocked and highly saline lagoon occupies the centre of the island, and fills the area of the former phosphate workings. The depth of the lagoon fluctuates with the tide, reaching a maximum depth of 60 cm at high water. The island is surrounded by a fringing reef, 100-200 m wide. The inferred mean annual rainfall is 800 mm. The prevailing winds are easterly trades.

ECOLOGICAL FEATURES The vegetation comprises stunted Sida fallax scrub with low herbs and grasses. Seven species have been recorded in five main vegetation types. The western part of the island is covered by an extensive mat of Tribulus cistoides, while inland saline flats support Sesuvium portulacastrum. Most of the remainder of the island supports a mixture of Portulaca lutea and Boerhavia albiflora. The highest ground is covered by Digitaria pacifica grass with scattered mats of Boerhavia and Tribulus on a coarse rubble substrate. Lepturus pilgerianus is located mostly on the west coast of the island, mixed with Tribulus cistoides (Garnett, 1983).

LAND TENURE State owned.

CONSERVATION MEASURES TAKEN McKean Island was declared a bird sanctuary in June 1938 under the Gilbert and Ellice Island Colony Wild Birds Protection Ordinance of 1938. The island was designated a Wildlife Sanctuary in 1975 under the 1975 Wildlife Conservation Ordinance (IUCN, 1991).

CONSERVATION MEASURES PROPOSED Dahl (1980) proposed the establishment of a national or international reserve in the Phoenix Islands, including McKean, Birnie, Phoenix, Enderbury, Orona (Hull) and possibly also Manra (Sydney), with Kanton Island as the communications link and surveillance centre. Garnett (1983) has made a number of general recommendations for management of the Phoenix Islands, including erection of multi-lingual notice boards advising visitors, such as long-distance yachtsmen and fishermen from Japanese, Taiwanese and Korean fleets, of the importance of the islands for science and nature conservation. Garnett (1983) also recommended that the Wildlife Sanctuary at McKean Island be upgraded to Closed Area.

LAND USE Uninhabited. The island was bonded under the 1856 American Guano Act in March 1859, and was mined for phosphate between 1839 and 1870, by which time all reserves were exhausted. A scheme to introduce coconuts was prevented by the outbreak of World War II. The island has seldom been visited, although there is a reasonably good anchorage off the west coast.

DISTURBANCES AND THREATS None known.

HYDROLOGICAL AND BIOPHYSICAL VALUES None known.

SOCIAL AND CULTURAL VALUES None known. The presence of Polynesian Rats suggests that McKean was visited by Polynesians in pre-historic times, but there is no evidence that the island was ever settled.

NOTEWORTHY FAUNA McKean is a very important breeding site for seabirds. Twenty-nine species have been recorded on the island, and 17 are known to breed. At least six of the breeding populations are considered to be of international significance. These are 5,000 Audubon's Shearwaters (Puffinus l'herminieri), 1,000 White-throated Storm Petrels (Nesofregatta (fuliginosa) albigularis), 40,000 Lesser Frigatebirds (Fregata ariel), 23,400 Grey-backed Terns (Sterna lunata), 20,000 Brown Noddies (Anous stolidus) and 15,000 Blue-grey Noddies (Procelsterna cerulea). The colonies of White-throated Storm Petrel and Lesser Frigatebird are the largest known colonies of these species in the world. The Polynesian Rat (Rattus exulans) is the only mammal, and the Mourning Gecko (Lepidodactylus lugubris) is the only reptile. Invertebrates include the hermit crab Coenobita perlata, the land crab Geograpsus grayii and at least 15 insects (Garnett, 1983).

NOTEWORTHY FLORA The relatively diverse and undisturbed terrestrial vegetation is considered to be of international conservation importance (Garnett, 1983).

SCIENTIFIC RESEARCH AND FACILITIES The island was visited by the Smithsonian Institution's Pacific Ocean Biological Survey Program in the 1960s, and has been visited by several ornithologists in recent years.

MANAGEMENT AUTHORITY AND JURISDICTION Wildlife Conservation Unit, Ministry of Line and Phoenix Development.

REFERENCES Dahl (1980, 1986); Garnett (1983); IUCN (1991); TCSP (1990).

REASONS FOR INCLUSION 1a, 2c. The island is valued for the variety and naturalness of its terrestrial habitats and large breeding populations of seabirds, several of which are of outstanding international importance.

SOURCE See references.