Projects

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Response of Native Plant Communities to Alien Species Management on the Island of Hawaii

Project Leader: Dr. David Foote, USGS Research Ecologist
HCSU Staff: not available

Introduced alien plant and animal species pose the greatest current threat to the management and maintenance of native Hawaiian ecosystems and the unique species they contain. Most of the management programs in Hawaii include control or removal of both alien animal and plant species from important conservation areas. As some of these problems are eliminated, particularly feral ungulate populations, it is important to track the response of both the native and alien plant populations. Following the response of native species subsequent to initiating management will help with assessing effectiveness of the actions and determining whether the vegetation succession is proceeding toward the expected community composition and structure target. However, in some cases, release of an area from the impacts of feral ungulates may result in a secondary increase in other weed species that could become problematic, which could require the initiation of additional management actions.

This study is designed to assess changes in the species composition, distribution and abundance of native and alien plants within the Kulani, Kilauea , and North Kona Forest sections of the Olaa-Kilauea Management Area following removal of feral ungulates and selected invasive plants from these habitats. The results will be used to modify management strategies for this area if alien plants increase significantly in abundance or distribution.

Hawaii Forest Bird Database Research

Project Leader: Dr.Thane K. Pratt, USGS Wildlife Biologist
HCSU Staff:

The Hawaii Forest Bird Interagency Database Project (HFBIDP) is a cooperative project of the US Geological Survey, the National Park Service, the Pacific Basin Information Node, US Fish and Wildlife Service, State of Hawaii, The Nature Conservancy, Bishop Museum, the Pacific Cooperative Studies Unit, the Hawaii Cooperative Studies Unit, and others.  Completed in 2004, the database includes over 400 historic surveys and over one million observations of forest birds conducted from 1976 to the present.  The database is updated continuously as new surveys are conducted. The database provides a storehouse of data that can be used in conjunction with information in a geographic information system (GIS) to analyze the distribution, abundance, and trends in forest bird populations, and to develop predictive species-habitat models. The database is housed at Kilauea Field Station, Hawaii Volcanoes National Park, and data are available to all cooperators via the project website: http://biology.usgs.gov/pierc/HFBIDPSite/HFBIDPHome.htm

For more information see USGS Fact Sheet 2006-3013 available at: http://biology.usgs.gov/pierc/Native_Birds/Forest_birds.pdf

Scales of Habitat Selection in the Endangered Hawaiian Hoary Bat (Lasiurus cinereus semotus)

Project Leader: Dr. Frank Bonaccorso, USGS Research Scientist
HCSU Staff: not available

The Hawaiian Hoary Bat (Lasiurus cinereus semotus) is the only extant land mammal native to the Hawaiian archipelago. It is listed as endangered due to apparent population declines, and a lack of knowledge concerning its distribution, abundance, and habitat needs. Recent work indicates that the bat may be more widely distributed than previously believed, use both native and non-native habitats, and may display seasonal variation in activity and habitat use patterns. This endangered species is now known to be present in timber stands and other commercial land use areas, and may therefore be affected by land use activities that alter forest structure in these areas. Agencies and landowners in Hawai‛i seek to assist in the creation of a sustainable forestry industry while also protecting bat populations and facilitating species recovery. In order to meet these goals and develop appropriate policy for land use practices and bat recovery, detailed information on the bat’s distribution, abundance, and habitat use must be obtained. We will investigate and quantify the foraging and roosting habitats of the Hawaiian hoary bat at a range of spatial scales and during different seasons. We will also assess the availability of suitable habitat and the status of such habitat relative to land use, particularly commercial timber management. In addition, thermoregulation of roosting bats will be quantified and related to seasonal distribution and habitat use.

Molecular Tools for the Genetic Analyses of Endemic and Invasive Species and Disease Organisms in Hawaii and Pacific Islands

Project Leader: Dr. Carter Atkinson, USGS Parasitologist
HCSU Staff: not available

The endemic flora and fauna of Hawaii and other Pacific islands have undergone extreme reductions in distribution and abundance since contact with both Polynesians and western civilizations, with many species and subspecies driven to extinction or reduced to a fraction of their former ranges. Many populations are fragmented, with little or no opportunity for gene flow, and are now susceptible to stochastic events like hurricanes, fires, and the impacts of invasive species and disease agents. Detailed information about the genetic structure of populations of threatened and endangered species and their historic genetic diversity and geographic uniqueness is becoming increasingly important for making decisions about their captive propagation and management and restoration in the wild. There is a critical need for application of modern genetic methods for the study of the historical and current diversity of threatened and endangered species as well as application of molecular tools to investigate the genetic diversity of invasive species and disease organisms, themselves. The impacts of many invasives on native species are still poorly documented and details about the genetic structure of these organisms may provide important clues about their biological characteristics that will be important for developing strategies for their control. Genetic information may also provide important information about the pathways of natural and anthropogenic movement of these organisms throughout the Pacific basin.

Palila Restoration Research

Project Leader: Dr. Paul Banko, USGS Wildlife Biologist
HCSU Staff:

The palila (Loxioides bailleui) is an endangered Hawaiian honeycreeper that has had the longest history of monitoring of any of Hawaii 's forest birds. Annual population estimates have fluctuated greatly with a mean population of 3,390 +/- 333 birds and a range of ~1,800-5,600 birds from 1980-1995. The palila is restricted to the west slope of Mauna Kea , occupying ~5% of its historical range. Palila depend on mamane (Sophora chrysophylla) forest for the majority of their dietary intake as well as for nesting sites and shelter. The quantity and quality of this dry subalpine mamane woodland has declined over many decades due to grazing pressure of introduced herbivores but is beginning to recover in many areas where ungulate numbers have been reduced. However, despite improving habitat conditions, the palila has not increased in numbers.

Mitigating the effects of realigning Saddle Road through a portion of the federally designated critical habitat for the Palila, requires research and management to protect, enhance, and reestablish Palila populations and to protect and restore habitat and food resources required by Palila. Undertaking these objectives requires detailed knowledge of Palila ecology and the subalpine dry forest habitat it occupies on Mauna Kea, Hawaii. These objectives also demand innovation, flexibility, and cooperation among mitigation partners, especially given the history of extinctions and the magnitude of other conservation problems in Hawaii. Starting in 1987, USGS-PIERC biologists have studied Palila biology and ecology, habitat and dietary preferences, and threats to their continued existence. Results from this research will be essential to guide restoration efforts.

Rare Plants of Hawaii Volcanoes National Park

Project Leader: Linda W. Pratt, USGS Botanist
HCSU Staff:

Hawaii Volcanoes National Park (HAVO) supports approximately 1,000 vascular plant species, and rare plant species comprise about 10% of the recorded flora. Among the nearly 400 native plant species known from the Park are 22 listed endangered and threatened plants, 5 candidates for endangered status, and 22 species of concern. An additional 40 species are rare or depleted within the Park. The habitat in which these rare and endangered plants occur ranges from disturbed coastal lowlands to nearly intact rain forests and subalpine ecosystems; a few species are restricted to small kipuka or unusual habitats in geothermal areas. Thirty years ago, the Park Service embarked on a program to eradicate feral goats from the Park, and feral pigs have been the recent focus of fencing and animal control efforts. Approximately 30% of the Park’s rain forest is now protected from feral pigs. For the last two decades Park Resource Managers have focused their attention on approximately 20 Special Ecological Areas (SEAs), which are considered to be the most intact and representative natural communities in the Park. These areas are typically fenced or within larger fenced units, and they are the focus of current feral animal and invasive alien plant control efforts. The distribution and abundance of rare plant species has been documented in several SEAs.

Despite decades of protection from feral animals and reduction of invasive alien plants, many rare plant populations have not increased or stabilized within the Park. By contrast, most common native plants of the SEAs have responded positively to management, and the habitats of many rare plants have seemingly recovered from feral animal damage. Factors other than feral ungulates and alien plants are limiting the recovery of most endangered plant species of HAVO. Possible limiting factors of these rare plant species include: loss of pollinators, flower and seed predation, loss of seed dispersers, seedling predation by alien rats and invertebrates, and lack of seedling establishment due to competition with alien grasses.

Park managers have begun re-introducing or augmenting rare plant populations in selected Special Ecological Areas. If these restored populations are to be self-sustaining, factors responsible for their original decline must be understood to allow development of adequate management strategies. Without such research, the Park’s management efforts may be less successful or efficient and some rare plant species will likely be lost from HAVO. Determination of the causes of reproductive failure of both extant and restored rare species will allow managers to stabilize remaining rare plant populations and prevent further losses.

Hawaiian Vegetation Mapping Project

Project Leader: Dr. Jim Jacobi, USGS Botanist
HCSU Staff: Paul Berkowitz, GIS/Database Management Specialist

The Hawaiian Vegetation Mapping Project was developed to produce detailed maps depicting the distribution of native and alien plant communities for various study areas throughout the Hawaiian Island chain. These vegetation maps will serve as the basis for sampling, analyzing, and interpreting other ecological data collected in four different study areas on the islands of Hawaii, Molokai, and Kauai. In the Hawaii sites the maps will be used as a foundation for a study of the distribution, abundance, and dynamics of rare plant and bird populations within the context of managing the native ecosystems where these species are found. On Molokai and Kauai the maps will support studies of watershed function and dynamics, as well as help document changes in plant community composition and structure relative to removal of feral ungulates. The work will involve using aerial photo interpretation and/or digital image analysis to produce vegetation maps and interpret characteristics of the vegetation depicted on the images. The image interpretation work will be supported by sampling the vegetation in ground-based study plots, and by additional aerial reconnaissance.

Maui Dry Forest Restoration

Project Leader: Dr. Arthur Medeiros, USGS Botanist
HCSU Staff: not available

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). 

Invasive Ants: Distribution, Ecological Impacts, and Control Methods

Project Leader: Robert Peck M.S., HSCU Food Ecology Research Specialist
HCSU Staff:

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.

Koa Community Ecology: Managing Alien Mammals

Project Leader:Dr. Paul Banko, USGS Wildlife Biologist
HCSU Staff:

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.

Mouflon Management Strategy Development

Project Leader: Dr. Steve Hess, USGS Wildlife Biologist
HCSU Staff: Tommy Thompson , Wildlife Research Specialist

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.     

Seabird Monitoring Plan and Techniques Manual

Project Leader: Dr. Michelle Reynolds, USGS Wildlife Biologist
HCSU Staff: not available

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.    

Consequences of Increasing Salinity for Anchialine Pool Communities in Hawaii

Project Leader: Dr. David Foote, USGS Wildlife Biologist
HCSU Staff: not available

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.   

Anchialine Pools are among the most threatened ecosystems in Hawaii. Destruction and alteration of anchialine pools as a result of coastal resort developments have been the most visible impact followed by the introduction of alien fish and other non-indigenous species. Water contaminants and excess nutrients are also ongoing concerns. While these impacts have been more localized, a potentially more pervasive threat involves changes in pool salinity associated with documented long-term reductions in stream flow and increased withdrawls of groundwater that feed into anchialine pool systems. The impacts of rising salinity on anchialine pool communities are unknown.