Hawaiian hoary bat is the only land mammal endemic to Hawaii and is listed as Endangered at both the state and federal levels. Hawaiian hoary bat is regularly included as a covered species in Habitat Conservation Plans developed for actions that may result in incidental “take” of the species; however, determination of recovery benefits has been challenging due to the paucity of information concerning threats, limiting factors, and ecology of the species. In collaboration with Hawaii’s Endangered Species Research Committee, we initiated a multi-year study in 2017 to investigate the overall distribution and seasonal occupancy of Hawaiian hoary bats on the Hawaiian island of O‘ahu. One of the primary objectives of the study was to investigate bat occupancy and distribution across O‘ahu. Data from acoustic bat detectors probabilistically distributed throughout the island and monitored year-round were used to assess bat distribution and seasonal occupancy over a five-year period. Bats were detected at 95% of detectors at least once during the study. However, activity rates were generally greater in the western and northwestern regions of the island. We present our findings on seasonal differences in bat distribution across O‘ahu and trends in occupancy estimated by season over the five-year study period.

Migratory shorebirds are declining worldwide, with serious implications for social-ecological systems. Indigenous stewardship facilitates an ability to sustain an abundance of biocultural resources, and could play a role in recovery of migratory shorebirds. Our co-developed research wove Indigenous science methodologies with those of conventional science to understand patterns for five species of shorebirds who connect Alaska with Hawaiʻi through annual migration: Kōlea (Pluvialis fulva); ʻŪlili (Tringa incana); ʻAkekeke (Arenaria interpres); Kioea (Numenius tahitiensis); and Hunakai (Calidris alba). A layered exploration of Indigenous observation methodologies from a loko iʻa (Hawaiian aquaculture system) and regional eBird data suggest: (1) decreases in juvenile recruitment of shorebirds across the Hawaiian Islands; (2) dissimilarities in oversummering patterns between the loko iʻa and the eBird dataset; (3) environmental characteristics which support large/diverse assemblages of migratory shorebirds. Co-interpretation of data showed correlations between climatic shifts and the phenologies of seasonal anchor events. Our findings strengthen and inform stewardship, conservation, and management practices for shorebirds at both ends of the migratory pathway.

As climate change progresses, we see increasing severe weather events, often hitting coastal communities and Pacific Islands the hardest. Alongside these events are small pests that pose a large threat to Pacific Island wildlife, food, and habitat. Little Fire Ants (LFA) and Coconut Rhinoceros Beetles (CRB) are rapidly spreading invasive pests. LFA sting native wildlife and make the plants inedible as a food source for wildlife. CRB attack variations of palms in addition to taro, destroying habitat specifically for native birds such as aeʻo (Hawaiian Stilt). This research examines case studies of specific storms across the Pacific: Typhoons Dolphin and Mawar in Guam, as well as case studies from detected high wind and high rainfall events in the Hawaiian Islands. Two types of spread were identified, initial spread and restoration spread. The initial spread refers to spread from the high winds and storm, whereas restoration spread follows the rebuilding efforts for impacted areas bringing in soil, compost, and other natural material that can be contaminated with CRB and LFA. Both types of spread are being mapped to represent the increase in spread of pests post-natural disaster, in order to visualize and help predict the long-lasting environmental and community impacts.

Avian malaria is a primary cause of native Hawaiian honeycreeper declines and extinctions. Without management of the disease or its vector, the southern house mosquito, several endangered honeycreepers will become extinct within one to ten years, and remaining species will continue to decline. Additionally, climate change has enabled the spread of mosquitoes and malaria into previously unaffected habitats, especially on Maui and Kauaʻi. The application of Incompatible Insect Technique (IIT) in key native forests and translocation of birds to refugia with lower disease prevalence on Hawaiʻi Island provide hope for critically endangered birds on other islands. We conducted surveys of bird and mosquito populations in high elevation native forests on Hawaiʻi Island in 2022 to assess their viability for conservation translocations and priority for mosquito control efforts. Initial results indicate avian malaria prevalence ranges from 0 to 0.75±0.15 (SE) in key indicator bird species. Mosquito surveys did not detect mosquitoes in some forests, while other locations housed moderate populations of mosquitoes that could transmit avian malaria locally. These data suggest that while some Hawaiʻi Island forests are viable targets for translocations of species from other islands, others are already in need of IIT and other forms of mosquito control to protect existing species. We will also provide updates on the current state of conservation actions aimed at protecting honeycreepers from extinction.

With hundreds of species on the brink of extinction, conservation practitioners must decide which conservation actions to implement given limited funds. Decision processes that aim to maximize conservation benefit for a given cost should address complementarity of actions across taxonomic groups. To address this need we modified a Priority Threat Management approach to guide resource allocation decisions for the conservation of biodiversity in Maui Nui (the islands of Maui, Moloka‘i, Lāna‘i, and Kahoʻolawe). Through expert elicitation, data were gathered on: (1) key threats to sensitive species; (2) management strategies to address key threats; and (3) expected cost, feasibility, and benefit of management strategies. Elicited data were analyzed to identify strategies that would provide optimal gains in recovery across multiple taxonomic groups given costs and feasibility. Predator control and fencing were identified as cost-efficient actions with the greatest gains in recovery across taxonomic groups, but those actions alone were not effective at recovering many plants and invertebrates. Participants emphasized the importance of investing in research and development of novel techniques to address persistent problems such as avian malaria and invasive pests. Findings from this study will improve the efficient use of existing funds and competitiveness for resources needed to achieve recovery.