Steven C Hess, Ph.D. (Former Employee)
Science and Products
Adaptation in Montane Plants
Montane plant communities in widely separated intact natural environments of the world have responded to changes in precipitation and temperature regimes by shifting both margins and core distributional ranges upward in elevation. Reduced evapotranspiration rates in cooler climate zones at higher elevation may compensate for less precipitation and higher temperatures within species’ former...
Feral Pig Abundance at Hakalau Forest National Wildlife Refuge
Feral pigs (Sus scrofa) have been identified as a significant problem in 120 U.S. National Wildlife Refuges. Pigs cause substantial degradation to natural ecosystems through rooting, digging, and browsing, but they are particularly destructive in Hawai‘I, which has no native terrestrial large mammals.
Invasive Mammals of the Pacific
The terrestrial biota of the Central Pacific is primarily defined by its degree of isolation. At the center lies the Hawaiian Archipelago, which is more than 3,200 km from any continental land mass. After tens of millions of years of evolutionary isolation from all mammals except bats, islands of the Central Pacific were quite suddenly besieged by a number of alien rodents, carnivores and...
Tracking Nēnē Movements Across Park Boundaries
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...
Kanakaleonui Bird Corridor Montane Plants 2016
The datasets used in the the research project entitled, "Facilitating Adaptation in Montane Plants to Changing Precipitation along an Elevation Gradient," are presented. Report available.
Habitat suitability and ecological associations of two non-native ungulate species on the Hawaiian island of Lanai
The ability to effectively manage game species for specific conservation objectives is often limited by the scientific understanding of their distribution and abundance. This is especially true in Hawai‘i where introduced game mammals are poorly studied and have low value relative to native species in other states. We modeled the habitat...
Hess, Steve C.; Fortini, Lucas; Leopold, Christina; Muise, Jacob; Sprague, Jonathan Hawaii as a microcosm: Advancing the science and practice of managing introduced and invasive species
Invasive species are a leading driver of global change, with consequences for biodiversity and society. Because of extraordinary rates of endemism, introduction, and extinction, Hawaii offers a rich platform for exploring the cross-disciplinary challenges of managing invasive species in a dynamic world. We highlight key successes and shortcomings...
Pejchar, Liba; Lepczyk, Christopher A.; Fantle-Lepczyk, Jean E; Hess, Steve C.; Johnson, M. Tracy; Leopold, Christina; Marchetti, Michael P.; McClure, Katherine M; Sheils, Aaron B Relationships between soil macroinvertebrates and nonnative feral pigs (Sus scrofa) in Hawaiian tropical montane wet forests
Nonnative feral pigs (Sus scrofa) are recognized throughout the New World as a highly significant introduced species in terms of ecosystem alteration. Similarly, nonnative soil macroinvertebrates (e.g. earthworms, ground beetles) invade and alter the structure and function of native habitats globally. However, the relationship between feral pigs...
Wehr, Nathaniel H. ; Litton, Creighton M; Lincoln, Noa K; Hess, Steve C. Facilitating adaptation to climate change while restoring a montane plant community
Montane plant communities throughout the world have responded to changes in temperature regimes by shifting ranges upward in elevation, and made downslope movements to track shifts in climatic water balance. Organisms that cannot disperse or adapt biologically to projected climate scenarios in situ may decrease in distributional range and...
Leopold, Christina; Hess, Steve C. The risk of rodent introductions from shipwrecks to seabirds on Aleutian and Bering Sea islands
Accidental introductions of rodents present one of the greatest threats to indigenous island biota, especially seabirds. On uninhabited remote islands, such introductions are likely to come from shipwrecks. Here we use a comprehensive database of shipwrecks in Western Alaska to model the frequency of shipwrecks per Aleutian and Bering Sea island,...
Renner, Martin; Nelson, Eric; Watson, Jordan; Haynie, Alan; Poe, Aaron; Robards, Martin D.; Hess, Steve C. Biology and impacts of Pacific Islands invasive species. 14. Sus scrofa the feral pig (Artiodactyla: Suidae)
Feral pigs (Sus scrofa L.) are perhaps the most abundant, widespread, and economically significant large introduced vertebrate across the Pacific island region. Unlike many other nonnative invasive species, feral pigs have both cultural and recreational importance in the region, complicating their management. Today, Pacific island feral pigs...
Wehr, Nathaniel H. ; Hess, Steven C.; Litton, Creighton M. Feral goats and sheep
No abstract available.
Pitt, William C.; Beasley, James; Witmer, Gary W.; Hess, Steve C.; Van Vuren, Dirk H.; Witmer, Gary W. Monitoring eradication of European mouflon sheep from the Kahuku Unit of Hawai‘i Volcanoes National Park
European mouflon (Ovis gmelini musimon), the world's smallest wild sheep, have proliferated and degraded fragile native ecosystems in the Hawaiian Islands through browsing, bark stripping, and trampling, including native forests within Hawai‘i Volcanoes National Park (HAVO). HAVO resource managers initiated ungulate control efforts in the 469 km2...
Judge, Seth; Hess, Steven C.; Faford, Jonathan K.; Pacheco, Dexter; Leopold, Christina Facilitating adaptation in montane plants to changing precipitation along an elevation gradient
Montane plant communities throughout the world have responded to changes in precipitation and temperature regimes by shifting ranges upward in elevation. Continued warmer, drier climate conditions have been documented and are projected to increase in high-elevation areas in Hawai‘i, consistent with climate change effects reported in other...
Hess, Steve C.; Leopold, Christina Conversion of native terrestrial ecosystems in Hawai‘i to novel grazing systems: a review
The remote oceanic islands of Hawai‘i exemplify the transformative effects that non-native herbivorous mammals can bring to isolated terrestrial ecosystems. We reviewed published literature containing systematically collected, analyzed, and peer-reviewed original data specifically addressing direct effects of non-native hoofed mammals (ungulates)...
Leopold, Christina R.; Hess, Steven C. A Tour de Force by Hawaii's invasive mammals: establishment, takeover, ecosystem restoration through eradication
Invasive mammals, large and small, have irreversibly altered Hawaii's ecosystems in numerous cases through unnatural herbivory, predation, and the transmission of zoonotic diseases, thereby causing the disproportionate extinction of flora and fauna that occur nowhere else on Earth. The control and eradication of invasive mammals is the single most...
Hess, Steve C. Federal collaboration in science for invasive mammal management in U.S. National Parks and Wildlife Refuges of the Pacific Islands
Some of the most isolated islands in the Pacific Ocean are home to US National Parks and Wildlife Refuges. These islands are known for flora and fauna that occur nowhere else, but also for invasive species and other factors which have resulted in the disproportionate extinction of native species. The control of invasive mammals is the single most...
Conner, L.M.; Smith, M.D.; Hess, Steven C.; Hu, Darcy; Loh, Rhonda; Banko, Paul C.