The endemic Hawiian Hawk (Buteo stolitarius), or `Io, has been listed as a federally endangered species since 1967.  The Endangered Species Act mandates periodic federal listing status reviews.  Previous studies have indicated that the `Io population has reached numbers that might warrant a status change.  The primary objective of this study is to estimate the Hawaiian Hawk distribution and abundance and map its habitat.  Study results will provide the preliminary information necessary for assessment of species recovery.  Accomplishing these two actions will also present essential baseline information for comparison to post-delisting population surveys and habitat monitoring.  This study will be based at the USGS Pacific Island Ecosystem Research Center (PIERC).  Fieldwork will be conducted throughout the island.   

Phase II Continuation

Diverse dryland forests and shrublands are among the most endangered of Hawaiian plant communities. Non-native ungulates, wildfire, and weeds have acted to completely eliminate native species from most leeward lowlands throughout the state. If no action is taken it is clear that these unique forest types will be lost forever.  Working with an array of partners, this phase of the project will involve two primary study sites on East Maui, Puu-o-Kali and Auwahi.  The Pu'u-o-kali lava flows support some of the most diverse and intact lowland dryland forest ecosystems remaining in the Hawaiian Islands and comprise, by far, the best remnant of lowland dryland forest vegetation on Maui.  The 900-1200 m elevation forest at Auwahi, with a very high diversity of native tree species, is generally considered the floristically richest dryland forest area in the state of Hawaii.  This restoration project incorporates a multi-faceted approach to eliminate suggested problems with previous restoration attempts.  Observations suggest that with protection from ungulate browsing and digging, strategic control of grasses, and restoration of favorable microhabitat, through planting and seeding relatively hardy native tree species to create a canopy, dryland forest restoration can be achieved at these sites and potentially several others on leeward East Maui. 

Phase III 

A newly established alien pest has profoundly modified the potential conservation of the Pu’u-o-kali wiliwili forest.  This gall wasp, first detected in Hawaii in April 2005, spread throughout the Hawaiian Islands, crippling wiliwili (Erythrina species) by deforming leaves, petioles, and twigs.  As part of developing the management plan, one of the overall project objestives, this phase focuses on the biology and potential management of the introduced wasp the Erythrina gall wasp (Quadrastichus erythrinae). 

Hawaiian plants and animals are uniquely vulnerable to the impacts of invasive ant species because they evolved without these powerful and widespread ecosystem transformers.  Although alien ant populations have been notoriously difficult to control worldwide, the urgency and magnitude of problems caused by ant invasions warrant additional attempts to refine existing management techniques and to test new tools.  Surveys along roads, buildings, and heavily visited tourists areas in Hawaii Volcanoes National Park (HAVO) indicate that Argentine ants (Linepithema humile) and big-headed ants (Pheidole megacephala) are patchily distributed but widespread within the original (Kīlauea-Keauhou) section of the park.  Park managers need information about the distribution and abundance of ants, environmental conditions that promote ant invasions, strategies and techniques for combating infestations in key ecological areas, and methods for preventing the spread of ants to effectively protect park resources.  The primary goals of this research are to determine actual and potential distributions of all species of ants within HAVO, understand the impacts of Argentine and big-headed ants on local native arthropod populations, test the efficacy of baits designed for their control, and develop and test protocols to prevent the spread of ants in the Kahuku section of HAVO and other areas.  At Haleakalā National Park (HALE), the main goal is to expand upon current efforts to control Argentine ants in the subalpine environment by testing alternate methods that show promise in HAVO.  Results from this work will provide, for the first time, distribution data on all ant species found within the park, which will allow managers to prioritize areas for ant control.

Major areas of the Hawaiian Islands’ forest were or still are dominated by koa (Acacia koa), and maintaining koa community health is crucial to restoring many native species and ecosystem functions over large areas. Koa is one of two dominant endemic tree species that have ecological and cultural importance.  Globally, koa also finds its place as one of the most valuable timber species.  It is of major significance to Hawaiian forest conservation that Koa communities have become degraded and reduced over time. However, managers have little detailed information that will help them restore the major constituent elements of koa forests and ecosystem processes needed to maintain forest health. Restoration involves replacing or supplementing missing and rare biological elements and removing the most damaging alien species. This work addresses the effects and effectiveness of managing alien mammals on the landscape during restoration.  Research will be conducted on the Island of Hawaii in areas dominated or co-dominated by koa forests including Hakalau Forest National Wildlife Refuge, the Kahuku Unit of Hawai`i Volcanoes National Park, the Ka`ū Forest Reserve, and the Kona Forest Unit of the Big Island NWR Complex.  These sites provide access to natural resources and allow researchers environmental factor control opportunities. The research conducted for these sites will serve as a model to manage and conserve natural resources statewide.

Herbivorous mammals have been introduced to oceanic island throughout the world often with devastating consequences for the native flora and subsequently fauna of these islands.  Because Hawaiian plants evolved in isolation from terrestrial mammals, most of these unique species do not have important defenses against these herbivores, such as thorns or secondary chemicals. Through browsing and bark stripping, a large and growing alien mouflon sheep (Ovis gmelini musimon) population threatens endemic plants such as the spectacular Ka`ū silversword (Argyroxiphium kauense) and endangered forest bird habitats at Kahuku. The recovery of rare Hawaiian plants in Kahuku cannot succeed without effective control measures for the burgeoning mouflon population.  This research will develop more efficient population monitoring and control methods for mouflon sheep, including population surveys, barriers, attractants, traps, and a coordinated adaptive control strategy. A key element of this research will be determining major mouflon social behavior patterns as they affect population aggregation and visibility.  The final report will detail various control strategies and their implications and generate maps that identify escape routes, traditional migratory routes, and habitat types.     

Sixty two species of seabirds and ducks breed in U.S. Pacific Islands. Seabirds and ducks face numerous anthropogenic threats such as oil spills, interactions with commercial fisheries, predation by introduced species, habitat loss, human disturbance, and global climate change. However, determining the status of populations, documenting population trends, and determining the effects of specific threats is difficult because seabirds spend most of their lives at sea or  breed on isolated islands; many species are nocturnal and/or nest in cryptic or inaccessible sites; and many species do not breed every year. Most island water birds are long-lived with low fecundity and therefore populations are highly vulnerable to small changes in adult survival. The USFWS and other wildlife managers need accurate and timely updates of island bird population status and trends to responsibly manage this resource. Seabirds I have been monitored at different scales, by an assortment of methodologies on different islands. Often the disparity between the data sets is such that combination and comparison is difficult and rarely is statistical analysis possible. It is critical that the USFWS establish a comprehensive and standardized monitoring program to determine long-term population trends and provide early warning of declines. This monitoring program must have a sound and defensible scientific foundation and be capable of detecting significant declines with sufficient reliability to allow implementation of management actions to avoid listing under the Endangered Species Act or enable downlisting of endangered species.    

Anchialine Pools are rare and localized mixohaline features along coastal lava flows that exhibit tidal fluctuations without a surface connection with the ocean. In Hawaii, these poold were frequently excavated or otherwise modified by Hawaiians to serve as sources of drinking water, baths and fish ponds. National Parks in Hawaii possess the full spectrum of pool types, from walled fish ponds to undisturbed pools collapsed lava tubes, cracks and caves. These pools possess a diverse assemblage of mixohaline species, including charismatic crustaceans and molluscs, as well as a more recently documented community of aquatic flies and odonates.