The atoll forms an elongated structure enclosing a narrow lagoon. There are two passes that split the rim into three sections.
The island supports substantial seabird populations.
Non-bird biodiversity: Coconut Crab is present in reasonable densities on the island.
Pressure/threats to key biodiversity
Invasive species poses a threat. Pacific Rats are present on the island. Both cats and dogs were recorded from the island in the 1960s but no evidence could be found on a search in 2006.
Conservation responses/actions for key biodiversity
Included in the assessment of the impact of invasive species on seabird populations in the Phoenix Island. Attempted eradication of pacific rats and (if they are found to still be present) cats would be considered at the third stage of the eradication process.
Is included as part of the Phoenix Islands Protected Area (PIPA).
Habitat and land use
A low lying coral atoll, much of the land is thickly vegetated with a Forest of Pisonia grandis and Cordia subcordata and interspersed with plantations of Cocus nucifera.
BirdLife International (2019) Important Bird Areas factsheet: Nikumaroro (Gardner Island). Downloaded from
http://www.birdlife.org on 20/05/2019.