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Click below for access to more than 170,000 publications written by USGS scientists over the century-plus history of the bureau.

Filter Total Items: 743

Groundwater and surface-water interactions in the He‘eia watershed, O‘ahu, Hawai‘i—Insights from analysis of historical data and numerical groundwater-model simulations

He‘eia and ‘Ioleka‘a Streams in the He‘eia watershed on O‘ahu, Hawai‘i, receive substantial discharge from dike-impounded groundwater. Previous studies indicated that groundwater withdrawals from the watershed affect streamflow. Resource managers and users seek information that can be used to balance the needs of competing uses of groundwater and streamflow in the watershed.In this study, analyses
Scot K. Izuka, Heidi L. Kāne, Kolja Rotzoll

Fine-resolution land cover mapping over large and mountainous areas for Lāna‘i, Hawaii using posterior probabilities, and expert knowledge

The task of accurately mapping species-specific vegetation cover in remote and topographically complex regions like those found in Hawaiʻi presents unique challenges. This study leverages a machine learning approach to accurately classify vegetation into fine species-specific classes across the island of Lāna‘i, Hawaii, offering a novel methodology for tackling such challenges. Utilizing high-reso
Lucas Fortini, Qiuming Cheng, Yoko Uyehara, Kari Bogner, Jonathan Sprague, Rachel Sprague

Videographic monitoring at caves to estimate population size of the endangered yǻyaguak (Mariana swiftlet) on Guam

The yǻyaguak (Mariana swiftlet; Aerodramus bartschi) is an endangered cave-nesting species historically found on Guam and the southern Mariana Islands, Micronesia. The population on Guam has been severely affected by the introduction of the brown treesnake Boiga irregularis. Population status assessments have, however, been challenging due to the limitations of traditional counting methods, which
P. Marcos Gorresen, Paul M. Cryan, Megan Parker, Frank Alig, Melia Gail Nafus, Eben H. Paxton

Identifying conservation introduction sites for endangered birds through the integration of lidar-based habitat suitability models and population viability analyses

Similar to other single-island endemic Hawaiian honeycreepers, the critically endangered ‘ākohekohe (Palmeria dolei) is threatened by climate-driven disease spread. To avert the imminent risk of extinction, managers are considering novel measures, including the conservation introduction (CI) of ‘ākohekohe from Maui to higher elevation habitats on the Island of Hawai’i. This study integrated lidar-
Lucas Fortini, Erica Gallerani, Christopher C Warren, Eben H. Paxton

Trajectories and tipping points of piñon–juniper woodlands after fire and thinning

Piñon–juniper (PJ) woodlands are a dominant community type across the Intermountain West, comprising over a million acres and experiencing critical effects from increasing wildfire. Large PJ mortality and regeneration failure after catastrophic wildfire have elevated concerns about the long-term viability of PJ woodlands. Thinning is increasingly used to safeguard forests from fire and in an attem
Michala Lee Phillips, Cara Marie Lauria, Tova Spector, John B. Bradford, Catherine A. Gehring, Brooke B. Osborne, Armin J. Howell, Edmund E. Grote, Renee Rondeau, Gillian Trimber, Benjamin Robinson, Sasha C. Reed

Environmental and geographical factors influence the occurrence and abundance of the southern house mosquito, Culex quinquefasciatus, in Hawai‘i

Hawaiian honeycreepers, a group of endemic Hawaiian forest birds, are being threatened by avian malaria, a non-native disease that is driving honeycreepers populations to extinction. Avian malaria is caused by the parasite Plasmodium relictum, which is transmitted by the invasive mosquito Culex quinquefasciatus. Environmental and geographical factors play an important role in shaping mosquito-born
Oswaldo Villena, Katherine Maria McClure, Richard J. Camp, Dennis Lapointe, Carter T. Atkinson, Helen Sofaer, Lucas Fortini

Limitations of invasive snake control tools in the context of a new invasion on an island with abundant prey

In October 2020, a new population of invasive brown treesnakes (Boiga irregularis) was discovered on the 33-ha Cocos Island, 2.5 km off the south coast of Guam. Cocos Island is a unique conservation resource, providing refuge for many lizards and birds, including endangered species, which were extirpated from mainland Guam by invasive predators including brown treesnakes. We sought to evaluate the
Shane R. Siers, Melia Gail Nafus, Jaried E. Calaor, Rachel M. Volsteadt, Matthew S. Grassi, Megan Volsteadt, Aaron F. Collins, Patrick D Barnhart, Logan Tanner Huse, Amy A. Yackel Adams, Diane L. Vice

Examining current bias and future projection consistency of globally downscaled climate projections commonly used in climate impact studies

The associated uncertainties of future climate projections are one of the biggest obstacles to overcome in studies exploring the potential regional impacts of future climate shifts. In remote and climatically complex regions, the limited number of available downscaled projections may not provide an accurate representation of the underlying uncertainty in future climate or the possible range of pot
Lucas Fortini, Lauren R. Kaiser, Abby G. Frazier, Thomas W Giambelluca

Landscape configuration alters movement behavior and space-use of a Hawaiian forest bird community

Habitat loss and fragmentation are considered the greatest threats to ecosystems worldwide. Movement reveals how individuals meet their habitat requirements and respond to environmental heterogeneity, and thus can provide a powerful tool for investigating how animals respond to changes in landscape configuration. In our study, we examined the effects of landscape configuration on the space use and
Kristina L. Paxton, Jennifer R Smetzer, Patrick J. Hart, Marti J Anderson, Eben H. Paxton

A global ecological signal of extinction risk in marine ray-finned fishes (class Actinopterygii)

Many marine fish species are experiencing population declines, but their extinction risk profiles are largely understudied in comparison to their terrestrial vertebrate counterparts. Selective extinction of marine fish species may result in rapid alteration of the structure and function of ocean ecosystems. In this study, we compiled an ecological trait dataset for 8,185 species of marine ray-finn
Trevor M. Bak, Richard J. Camp, Noel A. Heim, Douglas J. McCauley, Jonathan L. Payne, Matthew L Knope

Carbon dioxide (CO2) gas and eDNA monitoring as tools for eradicating invasive fish from anchialine pools in Hawai‘i

Invasive fish can profoundly affect communities they invade. In Hawai‘i, invasive fishes have become established in many anchialine pools, threatening the persistence of resident invertebrates, including several endangered species. Tools to eradicate invasive fishes from these pools are lacking. This study tested the efficacy of carbon dioxide (CO2) gas diffused into anchialine pool water as a met
Robert W. Peck, Maya Munnstermann, Malia Hayes, Carter T. Atkinson, Sallie Beavers, Aaron R. Cupp, Paul C. Banko

Empirical estimation of habitat suitability for rare plant restoration in an era of ongoing climatic shifts

Accurate estimates of current and future habitat suitability are needed for species that may require assistance in tracking a shifting climate. Standard species distribution models (SDMs) based on occurrence data are the most common approach for evaluating climatic suitability, but these may suffer from inaccuracies stemming from disequilibrium dynamics and/or an inability to identify suitable cli
Paul Krushelnycky, Lucas Fortini, Jeffrey Mallinson, Jesse Felts