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At least 721 records · Page 40Linked to original sources
USGS1917

Life zone investigations in Wyoming

Wyoming is among the foremost of our States in its wealth of natural scenery, culminating in the grandeur of Yellowstone National Park, one of the wonders of the world. In addition to this distinction it posseses vast open plains and lofty mountains whence flow the headwaters of mighty river systems emptying far away to the west into the Pacific Ocean, to the southeast into the Gulf of Mexico, and to the southwest into the Gulf of California. The various slope exposures of its mountain ranges, the fertility of its intervening valleys or basins, and the aridity of its desert spaces present a study of geographic and vertical distribution of wild life that is in many particulars unique. The study of geographic and vertical distribution of life with the governing factors and attendant problems is valuable as a matter of scientific research and in the attainment of practical knowledge. The Biological Survey has been making detailed investigations of the transcontinental life belts, or zones, of North America for some years, and this work has been carried on with special reference to their practical value. It has become increasingly evident that life zones furnish a fairly accurate index to average climatic conditions and, therefore, are useful as marking the limits of agricultural possibilities, so far as these are dependent upon climate. The knowledge thus gained has been published and made available as the investigations have progressed and the life zones have been mapped. 1

North American Fauna↗
USGS2023

Adult mosquito and butterfly exposure to permethrin and relative risk following ULV sprays from a truck-mounted sprayer

Ground applications of adulticides via a specialized truck-mounted sprayer are one of the most common practices for control of flying adult mosquitoes. Aerosols released to drift through a targeted area persist in the air column to contact and kill flying mosquitoes, but may also drift into adjacent areas not targeted by the applications where it may affect nontarget insects such as imperiled butterflies. This study compared the risk of permethrin to adult mosquitoes and adult butterflies to assess the likelihood that the butterflies would be affected following such sprays. Permethrin toxicity values were determined for Aedes aegypti and Culex quinquefasciatus (LD50s of 81.1 and 166.3 ng/g dw, respectively) and then combined with published toxicity data in a species sensitivity distribution for comparison with published permethrin toxicity data for adult butterflies. The sensitivity distributions indicated adult butterflies and mosquitoes are similarly sensitive, meaning relative risk would be a function of exposure. Exposure of adult butterflies and adult mosquitoes to permethrin was measured following their exposure to ULV sprays in an open field. Average permethrin concentrations on adult mosquitoes (912–38,061 ng/g dw) were typically an order of magnitude greater than on adult butterflies (110–11,004 ng/g dw) following each spray, indicating lower risk for butterflies relative to mosquitoes. Despite lower estimated risk, 100% mortality of adult butterflies occurred following some of the sprays. Additional studies could help understand exposure and risk for butterflies in densely vegetated habitats typical near areas treated by ULV sprays.

Archives of Environmental Contamination and Toxico↗
USGS2011

Imperfect science: Uncertainty, diversity, and experts

Seismic safety issues related to nuclear reactors in the eastern United States pose special challenges to the Earth and engineering sciences, given the severe consequences that can attend even very infrequent earthquakes. To deal with low-probability, potentially damaging ground motions, two major probabilistic seismic hazard analyses were conducted in the 1980s for nuclear reactors in the eastern United States, that part of the country east of the Rocky Mountains. The first study was performed by the Lawrence Livermore National Laboratory (LLNL) [ Bernreuter et al ., 1989] and was supported by the U.S. Nuclear Regulatory Commission (USNRC). The second was commissioned by the Seismicity Owners Group of the Electric Power Research Institute (EPRI) , [1989]. These studies generally agreed in terms of median hazard estimates, but mean hazard estimates at individual sites varied considerably, in several cases by 2 orders of magnitude or more.

Eos, Transactions, American Geophysical Union↗
USGS2000

Neogene geomorphic and climatic evolution of the central San Juan Mountains, Colorado: K/Ar age and stable isotope data on supergene alunite and jarosite from the Creede mining district

K/Ar age determinations or supergene alunite and jarosite, formed during Neogene weathering of the epithermal silver and base-metal ores of the Creede mining district, have been combined with geologic evidence to estimate the timing of regional uplift of the southern Rocky Mountains and related canyon cutting. In addition, oxygen and hydrogen isotopic studies suggest climate changes in the central San Juan Mountains during the past 5 m.y. Alunite [ideally (K,Na)Al 3 (SO 4 ) 2 (OH) 6 ] and jarosite [ideally KFe 3 (SO 4 ) 2 (OH) 6 ] can be dated by K/Ar or 40 Ar/ 39 Ar techniques and both contain OH and SO 4 sites that enable four stable isotope analyses (δD, δ 18 O OH , and δ 34 S) to be made. This supergene alunite and jarosite formed by weathering of sulfide-rich ore bodies may record the evolution of the chemical and hydrologic processes affecting ancient oxidized acid ground water, as well as details of climate history and geomorphic evolution. Fine-grained (1-10 μm) supergene alunite and jarosite occur in minor fractures in the upper, oxidized parts of the 25 Ma sulfide-bearing veins of the Creede mining district, and jarosite also occurs in adjacent oxidized Ag-bearing clastic sediments. K/Ar ages for alunite range from 4.8 to 3.1 Ma, and for jarosite range from 2.6 to 0.9 Ma. The δD values for alunite and jarosite show opposite correlations with elevation, and values for jarosite correlate with age. Calculated δD H2O values of alunite fluids approach but are larger than those of present-day meteoric water. Calculated δD H2O values for jarosite fluids are more variable; the values of the youngest jarosites are lowest and are similar to those of present-day meteoric water in the district. The narrow δD-δ 18 O SO4 values of alunites reflects oxidation of sulfide below the water table. The greater range in these values for jarosites reflects oxidation of sulfide under vadose conditions. The ages of alunite mark the position of the paleo-water table at the end of a period of moderate erosion from ca. 25 to 5 Ma that exposed the tops of the ore bodies to oxidation. The younger jarosite formed in the vadose zone during or following subsequent canyon cutting related to regional uplift of the southern Rocky Mountains, The δD values suggest that climates in the area were similar to those of the present day prior to regional uplift but went through a warm period before returning to present conditions during or after regional uplift. The results of this study indicate that the combined stable and radiogenic isotope analysis of supergene alunite and jarosite has broad application in understanding climate and geomorphic evolution of selected areas.

Colorado↗
USGS1958

Birds and Aircraft on Midway Islands, 1956-57 Investigations

The purpose of this study is to determine the extent to which certain species of birds contribute to the hazard to aircraft at Midway; to learn more about the population dynamics and habits of these species to determine what type of control measures might be possible without endangering the species; and to test methods of control which are suggested. Most of the study has been devoted to the two species of albatrosses and the sooty terns nesting at Midway because of the current belief that these species offered the greatest danger to aircraft safety.

Special Scientific Report - Wildlife↗
USGS2015

Evaluation and application of regional turbidity-sediment regression models in Virginia

Conventional thinking has long held that turbidity-sediment surrogate-regression equations are site specific and that regression equations developed at a single monitoring station should not be applied to another station; however, few studies have evaluated this issue in a rigorous manner. If robust regional turbidity-sediment models can be developed successfully, their applications could greatly expand the usage of these methods. Suspended sediment load estimation could occur as soon as flow and turbidity monitoring commence at a site, suspended sediment sampling frequencies for various projects potentially could be reduced, and special-project applications (sediment monitoring following dam removal, for example) could be significantly enhanced. The objective of this effort was to investigate the turbidity-suspended sediment concentration (SSC) relations at all available USGS monitoring sites within Virginia to determine whether meaningful turbidity-sediment regression models can be developed by combining the data from multiple monitoring stations into a single model, known as a “regional” model. Following the development of the regional model, additional objectives included a comparison of predicted SSCs between the regional model and commonly used site-specific models, as well as an evaluation of why specific monitoring stations did not fit the regional model.

Virginia↗
USGS2006

Growth and collapse of Hawaiian volcanoes

This special issue is an outgrowth of a session of the same name held at the 2003 Fall Meeting of the American Geophysical Union (AGU) in San Francisco. The session served dual purposes: to highlight recent advances in our understanding of the development and internal structure of Hawaiian volcanoes, and to recognize the important contributions of James Moore to this field of study.

Hawai'i↗
USGS2020

Shared functional traits explain synchronous changes in long‐term count trends of migratory raptors

Aim Assessing long‐term shifts in faunal assemblages is important to understand the consequences of ongoing global environmental change. One approach to assess drivers of assemblage changes is to identify the traits associated with synchronous shifts in count trends among species. Our research identified traits influencing trends in 73 years of count data on migrating raptors recorded in the north‐eastern USA. Location Pennsylvania, USA. Time period 1946–2018. Major taxa studied Birds of prey/raptors. Methods Migrating raptors were counted during autumn, following a standardized protocol. We used a hierarchical breakpoint model to identify when count trends shifted and to assess the role of traits in driving these trends before and after the breakpoint. Specifically, we quantified the probability of the direction (PD) of an effect of body mass, habitat or dietary specialization, migratory behaviour and susceptibility to dichlorodiphenyltrichloroethane (DDT) on count trends. Results We documented an assemblage‐wide mean shift in count trends of migrating raptors in 1974. In general, species that exhibited negative count trends before the breakpoint exhibited positive count trends afterwards. We found that traits associated with resource use (diet and habitat specialization) had high probabilities of affecting count trends, pre‐ and post‐breakpoint (> 90%). Moreover, the direction of their effects differed during both periods. Unexpectedly, other traits we evaluated, including DDT susceptibility, had relatively weaker associations with count trends. Main conclusions Trait‐based frameworks have promise for testing generalized assumptions about drivers of population trajectories. Historically, DDT was considered a key driver of changes in raptor population trends. However, our analysis suggests that other factors were also relevant. Moreover, the positive association between count trends and generalist behaviour depended on the temporal context. This result has implications for other settings where demographic trends can be linked to traits and help to identify drivers of biodiversity change.

Pennsylvania↗
USGS1984

Selected papers in the hydrologic sciences 1984; July 1984

The rapid, accurate measurement of the oxygen content of soil gas in the unsaturated zone or dissolved oxygen in soil water in the saturated zone can be useful in wetland vegetation studies. A method has been devised and tested in the Great Dismal Swamp, a wetland with fine silt-clay and organic soils, that appears to provide good results. A 60-milliliter sample of soil gas or water is withdrawn from permanently installed chambers at various depths in the soil profile. The oxygen concentration of air samples is measured with a specially constructed analyzer cell fitted to the polarographic oxygen electrode of a portable oxygen meter. The dissolved oxygen concentration of water samples is measured directly with the oxygen electrode while stirring the sample in a 32-milliliter glass bottle with a portable magnetic stirrer. Field tests with duplicate chamber installations showed that consistent results are obtained for soil gas and water.

Water Supply Paper↗
USGS2015

Book review: Biology and conservation of North American tortoises

The charismatic North American tortoises hold a special place in our culture and natural history. Despite the perseverance of these tortoises over millions of years, biologists now question their ability to persist into the future. In light of documented declines, habitat loss, and numerous threats to tortoise populations, the editors gathered a diverse group of researchers to review what we have learned about this group after decades of study, to summarize gaps in the literature, and to reflect on how we may use the current state of knowledge to conserve these fascinating species. Initially intended as a focused review of the two most well-studied species in the genus Gopherus , G. agassizii (Mohave Desert Tortoise) and G. polyphemus (Gopher Tortoise), the book developed into a comprehensive treatment of the entire genus. The editors offer the work as a resource to professional biologists and agencies working with North American tortoises as well as a teaching aid, hobbyist’s reference, and casual read for nature-lovers—although we presume that the former group is more likely to benefit than the latter. Although the book’s size appears modest, the content delivers an in-depth look at the five recognized tortoise species. Review info: Biology and Conservation of North American Tortoises. Edited by David C. Rostal, Earl D. McCoy, and Henry R. Mushinsky, 2014. ISBN 978-1421413778, 190 pp.

Herpetological Review↗
USGS2008

Ground-water quality data in the Southern Sacramento Valley, California, 2005 — Results from the California GAMA Program

Ground-water quality in the approximately 2,100 square-mile Southern Sacramento Valley study unit (SSACV) was investigated from March to June 2005 as part of the Statewide Basin Assessment Project of Ground-Water Ambient Monitoring and Assessment (GAMA) Program. This study was designed to provide a spatially unbiased assessment of raw ground-water quality within SSACV, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 83 wells in Placer, Sacramento, Solano, Sutter, and Yolo Counties. Sixty-seven of the wells were selected using a randomized grid-based method to provide statistical representation of the study area. Sixteen of the wells were sampled to evaluate changes in water chemistry along ground-water flow paths. Four additional samples were collected at one of the wells to evaluate water-quality changes with depth. The GAMA Statewide Basin Assessment project was developed in response to the Ground-Water Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The ground-water samples were analyzed for a large number of man-made organic constituents (volatile organic compounds [VOCs], pesticides and pesticide degradates, pharmaceutical compounds, and wastewater-indicator constituents), constituents of special interest (perchlorate, N -nitrosodimethylamine [NDMA], and 1,2,3-trichloropropane [1,2,3-TCP]), naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, and carbon-14, and stable isotopes of hydrogen, oxygen, and carbon), and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, matrix spikes) were collected at ten percent of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Assessment of the quality-control data resulted in censoring of less than 0.03 percent of the analyses of ground-water samples. This study did not evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, and (or) blended with other waters to maintain acceptable water quality. Regulatory thresholds apply to treated water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Health Services (CADHS) (Maximum Contaminant Levels [MCLs], notification levels [NLs], or lifetime health advisories [HA-Ls]) and thresholds established for aesthetic concerns (Secondary Maximum Contaminant Levels [SMCLs]). All wells were sampled for organic constituents and selected general water quality parameters; subsets of wells were sampled for inorganic constituents, nutrients, and radioactive constituents. Volatile organic compounds were detected in 49 out of 83 wells sampled and pesticides were detected in 34 out of 82 wells; all detections were below health-based thresholds, with the exception of 1 detection of 1,2,3-trichloropropane above a NL. Of the 43 wells sampled for trace elements, 27 had no detections of a trace element above a health-based threshold and 16 had at least one detection above. Of the 18 trace elements with health-based thresholds, 3 (arsenic, barium, and boron) were detected at concentrations higher an MCL. Of the 43 wells sampled for nitrate, only 1 well had a detection above the MCL. Twenty wells were sampled for radioactive constituents; only 1 (radon-222) was measured at activities higher than the proposed MCL. Radon-222 was detected below the threshold in 7 wells and above the threshold in 13 wells. SMCLs have been established for nine constituents or parameters analyzed in SSACV. Six were measured at levels higher than an SMCL: chloride, iron, manganese, pH, specific conductance, and total dissolved solids. Chloride, iron, manganese, pH, and total dissolved solids were measured in 43 wells: 27 wells had no measurements above a threshold and 16 wells had a measurement above a threshold. Specific conductance was measured in 83 wells. In 68 wells, specific conductance was measured lower than the threshold and in 15 wells it was measured above the threshold.

California↗
USGS2017

Groundwater-quality data from the National Water-Quality Assessment Project, January through December 2014 and select quality-control data from May 2012 through December 2014

Groundwater-quality data were collected from 559 wells as part of the National Water-Quality Assessment Project of the U.S. Geological Survey National Water-Quality Program from January through December 2014. The data were collected from four types of well networks: principal aquifer study networks, which are used to assess the quality of groundwater used for public water supply; land-use study networks, which are used to assess land-use effects on shallow groundwater quality; major aquifer study networks, which are used to assess the quality of groundwater used for domestic supply; and enhanced trends networks, which are used to evaluate the time scales during which groundwater quality changes. Groundwater samples were analyzed for a large number of water-quality indicators and constituents, including major ions, nutrients, trace elements, volatile organic compounds, pesticides, radionuclides, and some constituents of special interest (arsenic speciation, chromium [VI] and perchlorate). These groundwater-quality data, along with data from quality-control samples, are tabulated in this report and in an associated data release.

Data Series↗
USGS1979

A continuous water sampling and multi-parameter measurement system for estuaries

Salinity, temperature, light transmissivity, oxygen saturation, turbidity, pH, pCO2, and chlorophyll a fluorescence of a pumped water sample are continuously measured with a system designed primarily for estuarine studies. Near-surface water from a depth of 2 m is sampled continuously while the vessel is underway or water at depths to 100 m can be collected with an in situ pump, in which case the sampling depth and temperature are measured by an in situ probe. The system is comprised of commercially available instruments, equipment, and components, and of specialized items designed and fabricated by the authors. Data can be read from digital displays and analog strip-chart recorders. Tables and figures describing specialized items are included.

Open-File Report↗
USGS1999

Comparison of two approaches for determining ground-water discharge and pumpage in the lower Arkansas River Basin, Colorado, 1997-98

In March 1994, the Colorado Division of Water Resources (CDWR) adopted “Rules Governing the Measurement of Tributary Ground Water Diversions Located in the Arkansas River Basin” (Office of the State Engineer, 1994); these initial rules were amended in February 1996 (Office of the State Engineer, 1996). The amended rules require users of wells that divert tributary ground water to annually report the water pumped monthly by each well. The rules allow a well owner to report the pumpage measured by a totalizing flowmeter (TFM) or pumpage determined from electrical power data and a power conversion coefficient (PCC) (Hurr and Litke, 1989). Opinions by representatives of the State of Kansas, presented before the Special Master hearing a court case [State of Kansas v. State of Colorado, No. 105 Original (1996)] concerning post-Compact well pumping, stated that the PCC approach does not provide the same level of accuracy and reliability as a TFM when used to determine pumpage. In 1997, the U.S. Geological Survey (USGS), in cooperation with the CDWR, began a 2-year study to compare ground-water pumpage estimates made using the TFM and the PCC approaches. The study area was along the Arkansas River between Pueblo, Colorado, and the Colorado-Kansas State line (fig. 1). The two approaches for estimating ground-water discharge and pumpage were compared for more than 100 wells completed in the alluvial aquifer of the Arkansas River Basin. The TFM approach uses an inline flowmeter to directly measure instantaneous discharge and the total volume of water pumped at a well. The PCC approach uses electrical power consumption records and a power conversion coefficient to estimate the pumpage at ground-water wells. This executive summary describes the results of the comparison of the two approaches. Specifically, (1) the differences in instantaneous discharge measured with three portable flowmeters and measured with an inline TFM are evaluated, and the statistical differences in paired instantaneous discharge between the two approaches are determined; (2) short- and long-term variations in the PCC’s are presented; (3) differences in pumpage between the two approaches are evaluated, and the statistical differences in pumpage between the two approaches are determined; (4) potential sources of discrepancy between pumpage estimates are discussed; and (5) differences in total network pumpage using the two approaches are presented. During the irrigation seasons of 1997 and 1998, instantaneous discharge and electrical power demand were measured at randomly selected wells to determine PCC’s. At more than 100 wells, the PCC’s determined during the 1998 season were applied to total electrical power consumption data that was recorded between the initial and final readings at each network well site in 1998 to estimate total ground-water pumpage. At each site, an inline TFM was installed in a full-flowing, acceptable test section of pipe on the discharge side of the pump where the measurement of discharge was made. Measurements of instantaneous ground-water discharge also were made using three different types of portable flowmeters. The average velocity multiplied by the cross-sectional area of the discharge pipe was used to compute the discharge in gallons per minute. Whenever possible, discharge measurements were made at each network site using all three types of portable flowmeters.

Colorado↗
USGS1985

An investigation of hydraulic conductivity estimation in a ground-water flow study of Northern Long Valley, New Jersey

The purpose of this study was to develop a methodology to be used to investigate the aquifer characteristics and water supply potential of an aquifer system. In particular, the geohydrology of northern Long Valley, New Jersey, was investigated. Geohydrologic data were collected and analyzed to characterize the site. Analysis was accomplished by interpreting the available data and by using a numerical simulation of the watertable aquifer. Special attention was given to the estimation of hydraulic conductivity values and hydraulic conductivity structure which together define the hydraulic conductivity of the modeled aquifer. Hydraulic conductivity and all other aspects of the system were first estimated using the trial-and-error method of calibration. The estimation of hydraulic conductivity was improved using a least squares method to estimate hydraulic conductivity values and by improvements in the parameter structure. These efforts improved the calibration of the model far more than a preceding period of similar effort using the trial-and-error method of calibration. In addition, the proposed method provides statistical information on the reliability of estimated hydraulic conductivity values, calculated heads, and calculated flows. The methodology developed and applied in this work proved to be of substantial value in the evaluation of the aquifer considered.

Thesis↗
USGS1990

Photosynthetic pathways in freshwater aquatic plants

Recent studies show that generalizations about photosynthetic pathways, derived from terrestrial plant studies, do not apply to aquatic plants. Crassulacean acid metabolism (CAM) photosynthesis is of selective value not only in arid environments, where it enhances water-use efficiency, but also in aquatic plants of oligotrophic waters, where it enhances competitive ability in carbon acquisition. C 4 photosynthesis is present in many aquatic species, but in these species it is not coupled with the specialized anatomy of terrestrial C 4 plants. The ratio of the stable carbon isotopes, 13 C/ 12 C, in the biomass of terrestrial plants is a marker of their photosynthetic pathway. In aquatic environments, additional resistances to carbon-isotope fractionation make this technique of limited use in detecting photosynthetic pathways.

Trends in Ecology and Evolution↗
USGS2009

Constraining earthquake source inversions with GPS data: 2. A two-step approach to combine seismic and geodetic data sets

We present a new method to combine static and wavefield data to image earthquake ruptures. Our combined inversion is a two-step procedure, following the work of Hernandez et al. (1999), and takes into account the differences between the resolutions of the two data sets. The first step consists of an inversion of the static field, which yields a map of slip amplitude. This inversion exploits a special irregular grid that takes into account the resolution of the static data. The second step is an inversion of the radiated wavefield; it results in the determination of the time evolution of slip on the fault. In the second step, the slip amplitude is constrained to resemble the static slip amplitude map inferred from the GPS inversion. Using this combined inversion, we study the source process of the 2004 M6 Parkfield, California, earthquake. We conclude that slip occurred in two main regions of the fault, each of which displayed distinct rupture behaviors. Slip initiated at the hypocenter with a very strong bilateral burst of energy. Here, slip was localized in a narrow area approximately 10 km long, the rupture velocity was very fast (???3.5 km/s), and slip only lasted a short period of time (<1 s). Then the rupture proceeded to a wider region 12-20 km northwest of the hypocenter. Here, the earthquake developed in a more moderated way: the rupture velocity slowed to ???3.0 km/s and slip lasted longer (1-2 s). The maximum slip amplitude was 0.45 m. Copyright 2009 by the American Geophysical Union.

Journal of Geophysical Research B: Solid Earth↗
USGS2005

Rediscovery and uncertain future of high-elevation Haleakala carabid beetles (Coleoptera)

Recent biotic surveys in subalpine shrubland on Haleakalā Volcano, Maui, Hawai'i, have resulted in rediscovery of several species of carabid beetles previously known only from their nineteenth-century type specimens. Blackburnia lenta (Sharp), described from specimens collected just below Haleakalā summit in 1894, was found at lower elevational sites ranging from 2,400 to 2,750 m. Mecyclothorax rusticus Sharp, last seen in 1896, and M. nubicola (Blackburn), collected only in 1878, were also rediscovered in that vicinity. Recent collections of B. lenta contradict the U.S. Fish and Wildlife Service's previous classification of this species as one likely to be extinct. Nevertheless, B. lenta's known distribution comprises only 145 ha within an elevational zone that is bounded above and below by unicolonial populations of the invasive alien Argentine ant, Linepithema humile (Mayr). The known recent collections of M. rusticus and M. nubicola also occurred outside the distributional range of the Argentine ant. Mature eggs held in the lateral oviducts of B. lenta females averaged 1.4x the volume of the largest eggs previously reported among 13 species of Blackburnia. We hypothesize that the giant eggs of B. lenta result from selective forces favoring large, well-nourished developing and hatched first-instar larvae, consistent with a patchy distribution of suitable microhabitat and prey in the subalpine Haleakalā landscape. The specialized life history of B. lenta, and coincidence of distributional limits of the three rediscovered carabid species with range limits of the Argentine ant populations suggest that all would be jeopardized by future distributional expansion of Argentine ant. These intersecting phenomena compel us to conclude that B. lenta, M. nubicola, and M. nubicola are appropriate candidates for I.U.C.N. threatened species designation, pending further studies of their geographic ranges and historical trends in abundance.

Hawaii↗