Endangered Species in the Pacific Islands

Recovery Plan for the Ka‘u or Mauna Loa Silversword

	The Ka‘u or Mauna Loa Silversword (Argyroxiphium kauense) is a giant rosette plant found only in the active volcano of Mauna Loa on the island of Hawai‘i. This species was added to the Federal list of endangered species on April 7, 1993.
Mauna Loa Silversword - Photo credit Marie Bruegmann/USFWS

Habitat & Distribution:
The Ka‘u silversword may have once occurred in subalpine forests, bogs, and mountain parkland between 5,000 to 8,000 feet (1,500 to 2,500 meters) elevation. In2010, only about 700 wild individuals remain, but approximately 24,000 individuals have been reintroduced, and they have all been fenced to protect the plants from feral animals.

The largest population is located on national park land on Kahuku Ranch. Two smaller populations are located within Forest Reserves, managed by the Hawaii State Department of Land and Natural Resources.

The Kahuku Ranch population occurs in moist open forest with short stature ‘ōhi‘a trees and an understory of shrubs, grasses, and herbs. The substrate is a‘a (rough) lava with well developed soil. The populations in the Forest Reserves occur in a bog environment on weathered, old pahoehoe (smooth) lava with pockets of soil, in subalpine mountain parkland vegetation dominated by shrubby o`hia and scattered shrubs.

Recovery:
Browsing feral and domesticated animals has been identified as the primary reason for the decline of the Ka‘u silversword. Mouflon sheep, cattle, goats and pigs are currently a major threat to the silversword both at Kahuku and the Forest Reserves.

The recovery of the Ka‘u silversword should begin with securing large-scale habitat and stabilizing the current populations and control of feral animals through larger fenced areas and continued reintroduction efforts are of utmost importance.