Frugivorous birds play a crucial role in forest regeneration and seed dispersal in rainforest ecosystems. This is especially true in island ecosystems, where native mammalian seed dispersers are usually lacking. On the island of Kauai, many plants depend upon frugivorous birds for their dispersal, including olapa (Cheirodendron trigynum), lapalapa (C. platyphyllum), ohia ha (Syzygium sandwichensis), kanawao (Broussasia arguta), ohelo (Vaccinium spp.), painiu (Astelia spp.), pukiawe (Styphelia tameiameiae), kawau (Ilex anomala), and pilo (Coprosma spp.) (BRD unpubl. data).
Unfortunately, due to avian disease, introduced mammalian predators, habitat degradation and loss, and hurricanes, only one native frugivorous bird persists on Kauai in detectable numbers. This species, the Puaiohi, Myadestes palmeri, (picture at left) has been greatly reduced in numbers and range over the last century. Today no more 300 Puaiohi exist, most of them confined to a 10 km² area in the heart of the Alakai Wilderness Preserve (picture at right). Dispersal distances of wild Puaiohi are typically small (BRD unpubl. data), and so natural dispersal and expansion of the Puaiohi population into recovering habitat will be slow. As long as the population remains small and is restricted to such a limited area, it will remain at serious risk from stochastic demographic and environmental factors.
In 1995, a cooperative project was begun to develop methods for the recovery of the Puaiohi, with the participation of the U.S. Fish and Wildlife Service, Biological Resources Division/USGS, Hawaii Division of Forestry and Wildlife, and The Peregrine Fund (TPF). These efforts included an intensive study of the species' ecology in the wild; testing translocation and captive-rearing & release techniques for the closely related Omao, Myadestes obscurus; the establishment of a captive flock of Puaiohi at TPF's Keahou Bird Conservation Center on the island of Hawaii; and the development of captive-breeding and release techniques for the Puaiohi. The first release of Puaiohi into historic habitat took place in 1999, and the birds have been confirmed breeding in the wild.
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U.S. Department of the Interior |
U.S. Geological Survey