Regional Ecosystems Research

The Hawaiian Hoary Bat ( Lasiurus 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. Agencies and landowners in Hawai‘i seek to assist in the creation of sustainable uses for managed lands while also protecting bat populations...

Loss of wetlands, invasive plants, and non-native predators pushed Hawaii’s waterbirds to the brink of extinction by the early 1900s, although population numbers have improved somewhat in recent decades with conservation efforts. Nonetheless, all Hawaiian waterbirds have global population sizes estimated around or below below 2,000 individuals, making them still highly vulnerable to extinction...

Low-elevation Pacific islands are vulnerable to inundation from sea-level rise and sudden flooding events. The largely low-lying islands of Northwestern Hawaiian Islands (NWHI), that extend 1,930 km beyond the main Hawaiian Islands, are a World Heritage Site and part of the Papahānaumokuākea Marine National Monument. The NWHI support the largest tropical seabird rookery in the world, provide...

Islands and atolls throughout the Pacific have been impacted by invasive ant species. Threatening native ants and other arthropods with their aggressive behavior and ability to colonize large geographic areas, invasive ants pose one of the most serious threats to island ecosystems. This project focuses on three areas of the Pacific: American Samoa, Rose Atoll, and Johnston Atoll.

Six species of biting mosquitoes have been introduced to the Hawaiian Islands since Western contact, two of which are vectors of dengue, chikungunya, and Zika viruses. Environmental conditions favorable for the transmission of dengue and Zika occur year-long across Hawai‘i’s coastline. To better understand the ecology of vector mosquitoes and support public health efforts, mosquito monitoring at...

The rapid expansion of wind energy nationwide is an important step toward reducing dependence on non-renewable sources of power. However, the magnitude of the wildlife impacts at wind energy facilities is a newly recognized threat, and the cumulative long-term impacts to various bat species are of increasing concern. It is estimated that more than 450,000 bat fatalities now occur each year at wind...

Both wildlife and human health in Hawai‘i and other island ecosystems in the Pacific Basin face continued threats from introductions of diseases and vectors. Accidental introduction of mosquito-borne avian malaria and pox virus to Hawai‘i is an outstanding example of how biological invasions can have a profound effect on endemic wildlife. The geographic distribution, density, and community...

The Keamuku Maneuver Area (KMA) is a 9,227 ha. unit of Army Pohakuloa Training Area (PTA) on Hawai‘i Island. The Army’s mission at KMA is threatened by erosional processes that could make parts of the training area too hazardous or too degraded for sustained use. These processes depend on vegetation dynamics and the nature of the soils underlying KMA. Knowledge of the training area was...

The Laysan teal has the most restricted range of any duck species and is especially vulnerable to extinction because of its small population size and vulnerability to climate change. The species was believed to be endemic to one island until new sub-fossil evidence and ancient DNA-testing revealed Laysan teal were widespread across the Hawaiian archipelago. Despite its previously wide distribution...

USGS and Oregon State University (OSU) have joined forces to support USFWS with research needed help manage and recover the endangered Hawaiian duck, locally known as koloa maoli. Hybridization of koloa with feral Mallards on O‘ahu and Maui is believed to have resulted in complete introgression in those populations (Engilis et al. 2002), and Kaua‘i is the only island that likely supports a viable...

The federally endangered nēnē, or Hawaiian Goose, once present on most of the Hawaiian Islands, was found only on Hawai‘i Island by 1900. This remnant population was reduced to as few as 30 individuals by 1952 due to the combination of unregulated hunting, introduced mammalian predators, and large-scale habitat degradation. Nēnē have been restored to a few places like Hawai‘i Volcanoes National...

The palila is an endangered species of Hawaiian honeycreeper which exists only in subalpine forests dominated by māmane and naio on Mauna Kea Volcano. The diet of this finch-billed bird is unusually restricted; immature seeds, flowers, and insects found on māmane trees are critical to its existence. Māmane also is the preferred nesting substrate of the palila. Federal court orders have resulted in...