United States Pacific Island Wildlife Refuges Environment - 2024

Environment - current issues

Baker Island: no natural freshwater resources; feral cats, introduced in 1937 during a short-lived colonization effort, ravaged the avian population and were eradicated in 1965

Howland Island: no natural freshwater resources; the island habitat has suffered from invasive exotic species; black rats, introduced in 1854, were eradicated by feral cats within a year of their introduction in 1937; the cats preyed on the bird population and were eliminated by 1985

Jarvis Island: no natural freshwater resources; feral cats, introduced in the 1930s during a short-lived colonization venture, were not completely removed until 1990

Johnston Atoll: no natural freshwater resources; the seven decades under US military administration (1934-2004) left the atoll environmentally degraded and required large-scale remediation efforts; a swarm of Anoplolepis (crazy) ants invaded the island in 2010 damaging native wildlife; eradication has been largely, but not completely, successful

Midway Islands:  many exotic species introduced, 75% of the roughly 200 plant species on the island are non-native; plastic pollution harms wildlife, via entanglement, ingestion, and toxic contamination

Kingman Reef: none

Palmyra Atoll: black rats, believed to have been introduced to the atoll during the US military occupation of the 1940s, severely degraded the ecosystem outcompeting native species (seabirds, crabs); following a successful rat removal project in 2011, native flora and fauna have begun to recover

Climate

Baker, Howland, and Jarvis Islands: equatorial; scant rainfall, constant wind, burning sun;

Johnston Atoll and Kingman Reef: tropical, but generally dry; consistent northeast trade winds with little seasonal temperature variation;

Midway Islands: subtropical with cool, moist winters (December to February) and warm, dry summers (May to October); moderated by prevailing easterly winds; most of the 107 cm of annual rainfall occurs during the winter;

Palmyra Atoll: equatorial, hot; located within the low pressure area of the Intertropical Convergence Zone (ITCZ) where the northeast and southeast trade winds meet, it is extremely wet with between 400-500 cm of rainfall each year

Land use

other: 100% (2018 est.)