USGS Science⌕ Search

SEARCH · USGS Science

Results for “Snake”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources
USGS2021

Informing future condition scenario planning for habitat specialists of the imperiled pine rockland ecosystem of South Florida

This project evaluated habitat conditions for two species found in the imperiled pine rockland ecosystem—the Rim Rock Crowned Snake ( Tantilla oolitica ) and the Key Ring-Necked Snake ( Diadophis punctatus acricus ). The Rim Rock Crowned Snake historically occurred in eastern Miami-Dade County (hereafter, mainland) as well as throughout the Florida Keys, whereas the Key Ring-Necked Snake occurs only in lower Florida Keys (Enge et al. 2004; Mays and Enge 2016). Both species are very elusive, small (< 20 cm in length) and primarily fossorial. Pine rockland habitat is rapidly disappearing in South Florida, with < 3 percent of its original extent remaining. Saltwater intrusion from hurricanes and sea-level rise (SLR), and human development pose the greatest threats to the longevity of this ecosystem which, in turn, places species that are endemic to this unique habitat at risk of extinction. The Rim Rock Crowned Snake and the Key Ringed-Necked Snake are being considered for listing by the U.S. Fish and Wildlife Service (USFWS). To aid the agency’s decision, it must be able to forecast species’ responses to potential future environmental conditions, as well as to different conservation and management actions. Yet, the information needed to complete these forecasts—such as population trends, life history traits, habitat use, and future land use and climate conditions—is often lacking for most rare species. This is especially problematic for assessments of species resiliency to changes in climate and land use. When these types of data are lacking, information on habitat quality can be used to help determine how a species will respond to change. First, this project gathered current and historical records for both species from various sources such as museum specimens, inventories, and other personal account. Then, we identified potential future changes in habitat that could result from different management actions, such as habitat acquisition or restoration, and environmental conditions, such as changes in the frequency and intensity of tropical storms and rates of SLR. Researchers then explored the potential impacts of these habitat condition changes on the Rim Rock Crowned Snake and Key Ring-Necked Snake. This information can be used by the USFWS to help make decisions about the need to protect these species under the Endangered Species Act and could inform the conservation, management, and recovery of other at-risk species found in the pine rockland ecosystem. This work supports the Secretary of Interior’s priority to create a conservation stewardship legacy by using science to identify best practices to manage land and water resource and adapt to changes in the environment.

Florida↗
USGS2020

Response to terrestrial nest predators among endemic and introduced Hawaiian birds

Birds free from nest predators for long periods may either lose the ability to recognize and respond to predators or retain antipredator responses if they are not too costly. How these alternate scenarios play out has rarely been investigated in an avian community whose members have different evolutionary histories. We presented models of two nest predators (rat and snake) and a negative control (tree branch) to birds on Hawaiʻi Island. Endemic Hawaiian birds evolved in the absence of terrestrial predators until rats were introduced approximately 1,000 years ago. Introduced birds evolved with diverse predator communities including mammals and snakes, but since their introduction onto the island approximately one century ago have been free from snake predation. We found that (a) endemic and introduced birds had higher agitation scores toward the rat model compared with the branch, and (b) none of the endemic birds reacted to the snake model, while one introduced bird, the Red-billed Leiothrix (Leiothrix lutea), reacted as strongly to the snake as to the rat. Overall, endemic and introduced birds differ in their response to predators, but some endemic birds have the capacity to recognize and respond to introduced rats, and one introduced bird species retained recognition of snake predators from which they had been free for nearly a century, while another apparently lost that ability. Our results indicate that the retention or loss of predator recognition by introduced and endemic island birds is variable, shaped by each species' unique history, ecology, and the potential interplay of genetic drift, and that endemic Hawaiian birds could be especially vulnerable to introduced snake predators.

Hawaii↗
USGS2018

Duck nest depredation, predator behavior, and female response using video

Depredation plays an important role in determining duck nest success and predator and female duck behavior during nest depredation can influence nest fate. We examined depredation of mallard ( Anas platyrhynchos ) and gadwall ( A. strepera ) nests in Suisun Marsh, California, USA, in 2015–2016 with continuous infrared video monitoring to identify nest predators and characterize predator and female duck behavior during depredation events. We recorded predators at 44% of 147 nests monitored. Raccoons ( Procyon lotor ) were the most frequent predator observed at nests (40% of nests visited and 53% of depredated eggs) followed by striped skunks ( Mephitis mephitis ; 27% and 27%), coyotes ( Canis latrans ; 4% and 9%), common ravens ( Corvus corax ; 4% and 9%), gopher snakes ( Pituophis catenifer catenifer ; 19% and 0%), and western yellow‐bellied racers ( Coluber constrictor mormon ; 1% and 0%). The number of eggs depredated per depredation bout varied among predators (raccoons: 7.3 eggs; skunks: 2.5; coyotes: 7.4; ravens: 7.7; and snakes: 0.0). Mammal depredation occurred between 1600 and 0400, whereas snakes and ravens were observed at nests during the day (snakes: 1000–2100; ravens: 1700). Females flushed from nests immediately before predator arrival ( = 29.0 ± 16.6 [SD] sec), and this timing did not vary among predators. However, the length of nest depredation bouts varied among predators. Nest visits by gopher snakes were longer (18.6 ± 19.4 min) than depredation bouts by other predators (12.3 ± 10.7 min), but snakes did not successfully consume any eggs. Females took more time to return to nests when nests were depredated by raccoons (239 ± 137 min), whereas females returned more quickly when nests were visited by skunks (81 ± 163 min) or gopher snakes (15 ± 128 min). Partial clutch depredation occurred at 15% of depredated nests, but only 23% of partially depredated nests successfully hatched ≥1 egg. Our results indicate that predator type and behavior can influence female behavior and nest fate, and that management actions that reduce the effectiveness of raccoons and skunks encountering waterfowl nests may benefit these nesting populations.

Journal of Wildlife Management↗
USGS2021

When introduced prey violates trophic hierarchy: Conservation of an endangered predator

Introduced species often disrupt established food webs, but some native predators can come to rely on introduced prey. Understanding the net effects of the non-natives on imperiled predators is crucial for planning conservation measures. The invasive American bullfrog ( Lithobates catesbeianus ) can be prey, predator, and competitor for the critically endangered San Francisco garter snake ( Thamnophis sirtalis tetrataenia ). We examined the seasonal prey use of a San Francisco garter snake population that co-occurs with American bullfrogs to examine intraguild predation between these species. Juvenile and adult snakes mainly consumed native anurans instead of American bullfrogs, and this diet pattern peaked in spring, a critical foraging period for the snakes. In spring, large adult American bullfrogs also foraged heavily on native anurans and displayed a high degree of diet overlap with San Francisco garter snakes. Invasive American bullfrogs are detrimental to San Francisco garter snakes mainly through seasonal competition rather than reciprocal predation. Removal of invasive species provided further evidence that eliminating American bullfrogs can benefit San Francisco garter snakes by reducing predation pressure on their shared amphibian prey. Better understanding the interactions of invasive species with native species of conservation concern informs management practices and improves conservation outcomes.

Biological Conservation↗
USGS2017

Ecology of the Eastern Kingsnake (Lampropeltis getula) at Rainey Slough, Florida: A vanished Eden

Eastern Kingsnakes ( Lampropeltis getula ) are an important component and predator in herpetofaunal communities, but many Eastern Kingsnake populations have declined precipitously in the last few decades, particularly in the southeastern United States. Here, we describe an intensive capture–mark–recapture study of L. getula conducted during 1974–1978 in a canal bank–Water Hyacinth ( Eichhornia crassipes ) community at Rainey Slough in southern Florida, where annual capture probabilities of adults ranged from 0.662–0.787. Population size and structure, seasonal activity, movements, microhabitat use, behavior, thermal ecology, and predator–prey relationships are described. At this site kingsnakes were susceptible to capture mostly in winter and spring, were diurnal, used rodent ( Sigmodon hispidus ) burrows on canal banks as nocturnal retreats, and emerged from burrows on 13–26% of the sampling days. Overlap of burrow use by both sexes was extensive with no evidence of territoriality. Kingsnakes readily entered the Water Hyacinths to bask, pursue mates, and forage. At Rainey Slough only snakes were detected in the diet of kingsnakes. Concurrent sampling of potential snake prey in the hyacinths and on canal banks revealed 10 species that varied in use of the two sampled habitats and in body size. A range-wide analysis confirmed that in descending order snakes, reptile eggs, and lizards dominate the diet of L. getula in Florida (94.8%) and remain important prey types elsewhere (80.2%). At Rainey Slough the density of six species of semiaquatic snakes in Water Hyacinths averaged 3534 individuals/ha with a mean annual biomass of 135.8 kg/ha, and kingsnake biomass was only 2.2–3.9% of prey snake biomass. We estimated that the kingsnake population consumed 36.82–63.58 kg/yr, or about 10.0–17.2% of the standing crop of snakes in the Water Hyacinth community. Adult male L. getula lost on average 39.3% of their body mass associated with the spring reproductive season, whereas females lost only 3.4% in the same period. Body condition indices for both sexes improved substantially thereafter. In follow-up surveys at Rainey Slough during 2006–2010 no kingsnakes were found. Semiaquatic snake densities in the Water Hyacinths were 77.2% lower (807.4/ha) than in the 1970s and consisted of only three species. Compared to the enigmatic declines and extirpation of L. getula populations elsewhere, at Rainey Slough the primary cause likely was unsustainable mortality from road reconstruction and paving in the winter–spring of 1979 and subsequent roadkill. Other potentially causative agents of extirpation of L. getula in this system are discussed.

Florida↗
USGS2011

Scented guide ropes as a method to enhance brown treesnake (Boiga irregularis) trap capture success on Guam

Current methods for controlling the invasive Brown Treesnake ( Boiga irregularis ) on Guam include a modified minnow trap with a live mouse lure. We investigated the effects on capture success of augmenting these traps with scented guide ropes leading to trap entrances. Initial screening of scent preferences was based on time spent in scented and unscented arms of a Y-maze. Preferences of large and small snakes were scored for six different prey scents (live and carrion gecko, skink, and mouse). Large snakes spent more time in the maze arm scented with live gecko and carrion gecko, whereas small snakes spent more time in the arm scented with carrion mouse and carrion gecko. After the laboratory study, a pilot trapping session was conducted in the field using three treatments (live mouse-scented ropes, carrion gecko-scented ropes, and carrion mouse-scented ropes) and two controls (traps with unscented guide ropes and those with no ropes attached). Contrary to laboratory results, live mouse-scented ropes were most effective. We conducted a second trapping session using live mouse-scented ropes as well as the two controls used in the pilot study. For snakes of below-average to average condition, the number of captures for traps with live mouse-scented ropes was higher than for traps with no ropes. However, for snakes of above-average condition, there were no differences in capture rates between trap treatments. Overall, treatment effects were weaker than latent individual heterogeneity and the influence of snake body size, with large snakes trapped more readily.

Guam↗
USGS2011

Geophysical logs and water-quality data collected for boreholes Kimama-1A and -1B, and a Kimama water supply well near Kimama, southern Idaho

In September 2010, a research consortium led by scientists from Utah State University began drilling the first of three continuously cored boreholes on the Snake River Plain in southern Idaho. The goals of this effort, the Snake River Scientific Drilling Project, are to study the interaction between the Earth's crust and mantle, to identify potential geothermal energy sources, and to track the evolution of the Yellowstone hotspot on the Snake River Plain. The first borehole, located near Kimama, Idaho, is about 50 miles southwest of the U.S. Department of Energy's Idaho National Laboratory. Because geohydrologic data are scarce for that area of the central Snake River Plain, the Kimama borehole, completed in January 2011, provided a unique opportunity to collect geophysical and water-chemistry data from the eastern Snake River Plain aquifer system, downgradient of the laboratory. Therefore, in conjunction with the Snake River Scientific Drilling Project, scientists from the U.S. Geological Survey's Idaho National Laboratory Project Office conducted geophysical logging and collected water samples at the Kimama site. Wireline geophysical logs were collected for the diverging borehole, Kimama-1A and -1B, from land surface to 976 and 2,498 feet below land surface (BLS), respectively. Water samples were collected from Kimama-1A at depths near 460 and 830 feet BLS, and from the Kimama Water Supply (KWS) well located about 75 feet away. Geophysical log data included a composite of natural gamma, neutron, gamma-gamma dual density, and gyroscopic analysis for boreholes Kimama-1A and -1B. Geophysical logs depicted eight sediment layers (excluding surficial sediment) ranging from 4 to 60 feet in thickness. About 155 individual basalt flows were identified, ranging from less than 3 feet to more than 175 feet in thickness (averaging 15 feet) for borehole Kimama-1B (0 to 2,498 feet BLS). Sediment and basalt contacts were selected based on geophysical traces and were confirmed with visual inspection of core photographs. Temperature logs from the water table surface (about 260 feet BLS) to the bottom of borehole Kimama-1B (2,498 feet BLS) were nearly isothermal, ranging from about 62 to 64 degrees Fahrenheit. Gyroscopic data revealed that borehole Kimama-1B begins to separate from borehole Kimama-1A near a depth of 676 feet BLS. Drillhole azimuth and horizontal deviation at total logged depth for boreholes Kimama-1A and -1B were 172.6 and 188.3 degrees and 25.9 and 82.0 feet, respectively. Water samples were collected and analyzed for common ions; selected trace elements; nutrients; isotopes of hydrogen, oxygen, and carbon; and selected radionuclides. One set of water samples was collected from the KWS well and the two other sample sets were collected from borehole Kimama-1A near 460 and 830 feet BLS. With one exception, data for all three zones sampled near Kimama generally indicated that the water chemistry was similar. The exception was found in the deepest zone in borehole Kimama-1A (830 feet BLS) where concentrations probably were affected by the drilling mud. A comparison of the inorganic, organic, and stable chemistry data between the KWS well and the 460-foot zone in borehole Kimama-1A indicated similar chemistry of the aquifer water, except for some variability with nitrate plus nitrite, orthophosphate, iron, zinc, and carbon-14. Radionuclide concentrations were either less than reporting levels or at background levels for the eastern Snake River Plain aquifer.

Idaho↗
USGS2018

Findings from a preliminary investigation of the effects of aquatic habitat (water) availability on giant gartersnake (Thamnophis gigas) demography in the Sacramento Valley, California, 2014–17

The giant gartersnake ( Thamnophis gigas ) is a semi-aquatic species of snake precinctive to the Central Valley of California. Because the Central Valley has experienced a substantial loss of wetland habitat, giant gartersnake populations are largely found in aquatic habitats associated with rice agriculture. In dry years, less water may be available for rice agriculture, resulting in less aquatic habitat, which could have cascading effects on giant gartersnake populations. We present 2 years of data intended to examine how the demography of giant gartersnakes is affected by the availability of aquatic habitat on the landscape (2016–17), along with 2 years of (sparse) preliminary data (2014–15) collected as part of an earlier radio-telemetry study on giant gartersnake movement behavior. We sampled agricultural canals near rice fields for giant gartersnakes at 8 sites distributed throughout the Sacramento Valley. Five sites were sampled from 2014–17, and 3 sites were sampled from 2015–17. In total, we made 2,995 captures of 1,011 snakes from 2014–17. We used these capture data to fit a multi-site Jolly-Seber model to estimate the abundance of giant gartersnakes as well as the daily and annual probability of capture at each site. We used remotely sensed Landsat data to characterize the extent of flooded rice fields surrounding each site in each year. In addition, we collected 175 females from 2014–17 and delivered them to the Sacramento Zoo for health assessments and reproductive exams. The abundance of giant gartersnakes varied among sites, and abundance estimates were more precise in 2016 and 2017 when sampling effort was greatest. The probability of a giant gartersnake being captured at least once in a year was higher in 2016 and 2017 than 2014 and 2015, and recaptures of snakes marked the previous year were highest in 2016 and 2017 as well. Mean annual apparent survival was estimated to be 0.40 but varied among sites from a low of 0.14 to a high of 0.63. Five sites had diverse size distributions that included abundant sub-adult and large adult female snakes. One site had a truncated size distribution with few large adult female snakes, and 2 sites had mostly large adult-sized snakes and few small individuals. Both the probability a female was gravid and a female’s litter size were positively related to the female’s snout-vent length. Somatic growth rates varied more among years than among sites, and females grew faster (in millimeters per day) than male snakes. The proportion of the landscape around each site under active rice cultivation fluctuated over time (generally between 60–90 percent of the landscape was active rice growing, although this proportion was lower for some sites in some years), and variation in rice growing was asynchronous among sites. This study demonstrates that intensive demographic sampling enables estimation of several key demographic variables at each study site. Continued sampling would allow for investigating potential relationships between the amount of rice growing at a site and demographic parameters such as growth, survival, and reproduction.

California↗
USGS1967

Ground water in the vicinity of American Falls Reservoir, Idaho

Analysis of ground- and surface-water relationships suggests that increasing the capacity of the American Falls Reservoir by raising the height of the dam 15 feet would increase leakage from the reservoir by less than 0.2 percent of the average inflow to the reservoir, or less than 10,000 acre feet per year. This amount is less than one-tenth of the evaporation rate from the reservoir. The American Falls Reservoir lies near the south margin of the Snake River Plain in southeastern Idaho. The Snake River Plain is about 200 miles long and averages nearly 60 miles in width. It is underlain by a thick sequence of basaltic lava flows, interbedded pyroclasties, and sedimentary deposits. The uppermost few thousand feet of this sequence is the Snake Plain aquifer, one of the great aquifers of the United States. Recharge to the aquifer is chiefly by water percolating from the Snake River, its tributaries, and irrigated tracts, and by underflow from surrounding areas. Ground water moves generally southwestward and discharges to the Snake River through springs in the American Falls Reservoir reach and in the Hagerman Valley reach (between Twin Falls and Bliss). Total discharge from the aquifer is about 9,000 cfs (cubic feet per second). The occurrence and movement of ground water in the viscinity of American Falls Reservoir are controlled by the local geology. Silt and tuff in the Neeley Formation and the Walcott Tuff and silt and fine sand in the FT ft Formation and American Falls Lake Beds have a low permeability. These rocks transmit little ground water compared with the basalt and intercalated pyroclasties and gravels of the Snake Plain aquifer. The less permeable deposits underlie the reservoir area and act as a barrier to the movement of ground water. Under present conditions the water table on the periphery of the reservoir slopes toward the reservoir, except within 3 or 4 miles of the dam, where the water table slopes away from the reservoir. Most of the springs discharge at altitudes above 4,370 feet, some 15 feet above the maximum reservoir stage. Thus, reservoir stage has little effect on ground-water inflow to the reservoir. A fairly close relationship exists between the annual amount of surface water diverted for irrigation of lands up the Snake River from the reservoir and the annual ground-water discharge through springs for the period 1911-60. After about 1952, greatly increased ground-water withdrawals from wells, which increased consumptive use, virtually balanced increased diversions from the surface- water system for irrigation, so that ground-water inflow to the reservoir remained about constant.

Idaho↗
USGS2015

Factors affecting defensive strike behavior in Brown Treesnakes ( Boiga irregularis ) provoked by humans

Striking is a typical antipredator defense exhibited by many species of snakes. While trapping Brown Treesnakes (Boiga irregularis) on Guam, we observed that snakes most frequently struck at an approaching person at a site where snakes had been trapped, marked, and handled in the past. Using a combination of between-sites and within-site comparisons, we assessed if the propensity to strike was correlated with capture histories (both recent and long-term), snake size, body condition (a proxy to nutritional stress), sex, or tail condition (broken or intact), while controlling for confounding variables. We confirmed that propensity to strike was higher at the site where we had been conducting capture-mark-recapture for several years. However, we were unable to demonstrate a correlation between striking tendencies and individual recent or long-term capture histories. The only morphological covariate that had an effect on strike propensity was sex, with females striking more often than males. After removing the site effect from our model, we found that snakes missing parts of their tails were more likely to strike than snakes with intact tails. We have yet to identify the factor(s) that cause the pronounced difference across sites in snake propensity to strike, and data from additional sites might help elucidate any geographical patterns.

Herpetological Conservation and Biology↗
USGS2017

Crotalus oreganus lutosus (Great Basin Rattlesnake). Defensive behavior/head hiding and tongue display

A variety of snake species employ head hiding as defensive behavior (Greene 1973. J. Herpetol. 7:143–161), but such behavior seems to be rarely observed in rattlesnakes. A recent report (Medica 2009. Herpetol. Rev. 40:95–97) presented observations on Crotalus scutulatus scutulatus and cited cases of similar behavior involving C. atrox , C. ruber , and C. viridis viridis . Here we report an encounter on 28 May 2016 with a C. oreganus lutosus (total length ca. 900 mm) observed 16 km S of Fallon, Churchill County, Nevada, USA. At 0925 h this snake was spotted by AKJ near the edge of the pavement on U.S. Hwy. 95. When approached, the snake presented typical active defensive behavior, with the rattle elevated (although not rattling), striking occasionally, and frequently flicking its conspicuous lavender and black tongue. As AKJ continued to take pictures the snake coiled more tightly (Fig. 1A), maintaining its rattle concealed and finally hiding its head beneath its coils (Fig. 1B). After photographing this pose AKJ made his first physical contact with the snake by scooping it up with a small shovel and placing it off the road. At this point the snake recovered its feisty attitude and would not retreat despite attempts to move it further away from the road. The snake did not rattle during the entire encounter (which lasted less than 5 min). Head hiding as a “last resort” in response to a persistent unavoidable threat may be more widespread within the family Crotalidae than previously documented.

Nevada↗
USGS2009

Prey preferences and prey acceptance in juvenile Brown Treesnakes (Boiga irregularis)

On the Pacific island of Guam, control of the invasive Brown Treesnake (Boiga irregularis) relies largely on methods that use mice as bait. Juvenile B. irregularis feed primarily on lizards and their eggs, but little is known about their prey preference. We conducted an experiment to investigate preferences for, and acceptance of, dead geckos, skinks, and neonatal mice, in juvenile B. irregularis ranging from 290 mm to ca. 700 mm snout-vent length (SVL). Snakes of all sizes showed a preference for geckos over skinks and neonatal mice. Geckos were the first prey chosen in 87% of 224 initial trials (56 snakes subjected to four trials each; 33% would be expected from a random choice). The smallest snakes had the most pronounced preference. Although many of the snakes accepted neonatal mice and/or skinks, some snakes of all sizes were reluctant to feed on anything but geckos, especially when well fed. We also addressed the hypothesis that repeated encounters with a particular prey type increase a snake's preference for that prey. Our study does not support this hypothesis. Our results suggest that control methods relying solely on rodent bait may be inefficient for targeting snakes < 700 mm SVL and that individual heterogeneity in prey preference may cause a significant part of this juvenile cohort to be completely refractory to capture with rodent bait, even if the bait is dead and small enough to be readily swallowed.

Herpetological Conservation and Biology↗
USGS2011

Genetic variation in westslope cutthroat trout Oncorhynchusclarkii lewisi : implications for conservation

Twenty-five populations of westslope cutthroat trout from throughout their native range were genotyped at 20 microsatellite loci to describe the genetic structure of westslope cutthroat trout. The most genetic diversity (heterozygosity, allelic richness, and private alleles) existed in populations from the Snake River drainage, while populations from the Missouri River drainage had the least. Neighbor-joining trees grouped populations according to major river drainages. A great amount of genetic differentiation was present among and within all drainages. Based on Nei&rsquo;s DS, populations in the Snake River were the most differentiated, while populations in the Missouri River were the least. This pattern of differentiation is consistent with a history of sequential founding events through which westslope cutthroat trout may have experienced a genetic bottleneck as they colonized each river basin from the Snake to the Clark Fork to the Missouri river. These data should serve as a starting point for a discussion on management units and possible distinct population segments. Given the current threats to the persistence of westslope cutthroat trout, and the substantial genetic differentiation between populations, these topics warrant attention.

Idaho, Montana↗
USGS2022

Invasive brown treesnakes (Boiga irregularis) move short distances and have small activity areas in a high prey environment

Animal movements reflect temporal and spatial availability of resources as well as when, where, and how individuals access such resources. To test these relationships for a predatory reptile, we quantified the effects of prey abundance on the spatial ecology of invasive brown treesnakes ( Boiga irregularis ) on Guam. Five months after toxicant-mediated suppression of a brown treesnake population, we simultaneously used visual encounter surveys to generate relative rodent abundance and radiotelemetry of snakes to document movements of surviving snakes. After snake suppression, encounter rates for small mammals increased 22-fold and brown treesnakes had smaller mean daily movement distances (24 ± 13 m/day, x &#x00AF; "> x ± SD) and activity areas (5.47 ± 5 ha) than all previous observations. Additionally, snakes frequenting forest edges, where our small mammal encounters were the highest, had smaller mean daily movement distances and three-dimensional activity volumes compared to those within the forest interior. Collectively, these results suggest that reduced movements by snakes were in part a response to increased prey availability. The impact of prey availability on snake movement may be a management consideration when attempting to control cryptic invasive species using tools that rely on movement of the target species to be effective,

Guam↗
USGS1983

Geothermal resources of southern Idaho

The geothermal resource of southern Idaho as assessed by the U.S. Geological Survey in 1978 is large. Most of the known hydrothermal systems in southern Idaho have calculated reservoir temperatures of less than 150?C. Water from many of these systems is valuable for direct heat applications, but is lower than the temperature of interest for commercial generation of electricity at the present time. Most of the known and inferred geothermal resources of southern Idaho underlie the Snake River Plain. However, major uncertainties exist concerning the geology and temperatures beneath the plain. By far the largest hydrothermal system in Idaho is in the Bruneau-Grand View area of the western Snake River Plain with a calculated reservoir temperature of 107?C and an energy of 4.5? 10 20 joules. No evidence of higher temperature water associated with this system has been found. Although the geology of the eastern Snake River Plain suggests that a large thermal anomaly may underlie this area of the plain, direct evidence of high temperatures has not been found. Large volumes of water at temperatures between 90? and 150?C probably exist along the margins of the Snake River Plain and in local areas north and south of the plain. Areas that appear particularly promising for the occurrence of large high-temperature hydrothermal systems are: the area north of the Snake River Plain and west of the Idaho batholith, the Island Park area, segments of the margins of the eastern Snake River Plain, and the Blackfoot lava field.

Circular↗
USGS1954

Records of wells, ground-water levels, and ground-water withdrawals in the lower Goose Creek Basin, Cassia County, Idaho

Investigations by the United States Geological Survey of Ground Water in the Southern border area of the Snake Rive Plain, south of the Snake River, a re concerned at the present time with delineation of the principal ground-water districts, the extent and location of existing ground-water developments, the possibilities for additional development, and the effects of ground-water development on the regimen of streams and reservoirs whose waters are appropriate for beneficial use. The lower part of the Goose Creek Basin is one of the important ground-water districts of the southern plains area and there are substantial but spotty developments of ground water for irrigation in the basin. Several thousand irrigable acres that are now dry could be put under irrigation if a dependable supply of ground water could be developed. The relations of the ground-water reservoirs to the regime of the Snake River and Goose Cree, and to the large body of ground water in the Snake River Plain north of the Snake, are poorly known. A large amount of geologic and hydrologic study remains to be done before those relations can be accurately determined. Investigations will be continued in the future but file work and preparation of a comprehensive report inevitably will be delayed. Therefore the available records are presented herein in order to make them accessible to farmers, well drillers, government agencies, and the general public. Interpretation of the records is not attempted in this report and is deferred pending the accumulation of additional and quantitative information. The data summarized herein include records of the locations and physical characteristics of wells, the depth to water in wells, fluctuations of water levels in observation wells, and estimated rates and volumes of seasonal ans yearly ground-water pumpage for irrigation, municipal, and other uses. This information is complete for work done as of December 31, 1952. The investigations upon which this report is based were undertaken in cooperation with the U.S. Bureau of Reclamation, Region I, at the request of the Planning Division, Central Snake River District. The report was complied in the first instance for the use of the Bureau of Reclamation but is now released to the public. The observation-well program in the area has been maintained in cooperation with the Idaho State Department of Reclamation as part of the regular cooperative program of the Geological Survey.

Idaho↗
USGS1986

Hydraulic properties of rock units and chemical quality of water for INEL-1 — A 10,365-foot deep test hole drilled at the Idaho National Engineering Laboratory, Idaho

A 10,365-ft deep test hole drilled at the INEL (Idaho National Engineering Laboratory) in southeastern Idaho provided hydraulic information for rock units underlying the Snake River Plain aquifer. Four aquifer tests showed that the hydraulic conductivity decreased with depth--from an average of 0.03 ft/day for the interval from 1,511 to 2,206 ft below land surface to an average of 0.002 ft/day for the interval from 4 ,210 to 10,365 ft. In contrast the hydraulic conductivity of the Snake River Plain aquifer ranges from 1 to 100 ft/day. The hydraulic head increased with depth; the head at depth was about 115 ft greater than that for the Snake River Plain aquifer. Water temperature in the test hole increased from 26 C at 600 ft below land surface to 146 C at 9,985 ft. The gradient was nearly linear and averaged about 1.3 C/100 ft of depth. Water from the Snake River Plain aquifer contained 381 mg/L of dissolved solids and had a calcium bicarbonate chemical composition. The dissolved solids concentration in underlying rock units ranged from 350 to 1,020 mg/L and the water had a sodium bicarbonate composition. Hydrologic data for the test hole suggest that the effective base of the Snake River Plain aquifer near the test hole is between 840 and 1,220 ft below land surface. The upward vertical movement of water into the Snake River Plain aquifer from underlying rock units could be on the order of 15,000 acre-ft/year at INEL. (Author 's abstract)

Idaho↗
USGS1994

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Owyhee and Vale Projects, Oregon and Idaho, 1990-91

A reconnaissance investigation was conducted during 1990--91 in the Owyhee and Vale projects in eastern Oregon and southwestern Idaho, as well as at a number of sites in the Snake River and tributaries to the Snake River in the area of study. The objective of the study was to determine if agricultural drainwater entering the study area was causing, or had the potential to cause, significant harmful effects to human health, fish and wildlife, or may adversely affect the suitability of water for beneficial uses. Approximately 153,000 acres of land are irrigated annually within the areas of the Owyhee and Vale projects. Large quantities of water are required because of the semiarid climate and relatively high evaporation rates. Several reservoirs in the area are filled annually during the wet, nonirrigation season to sustain irrigation during the dry summer months. During the irrigation season, this impounded water, along with direct diversions from the Malheur, Owyhee, and Snake Rivers, is transported to the irrigated areas through a series of diversion tunnels, siphons, canals, aqueducts, ditches, and drains. Major crops grown in the area include sugar beets, alfalfa hay and other hay crops, onions, and winter wheat. Minor crops include corn, potatoes, mint, various seed crops, and fruit. In 1987, it was estimated that the following amounts of pesticides were used in the project areas: 2,4-D (21,000 lbs [pounds]), chlorpyrifos (1,000 lbs), dacthal (40,000 lbs), dicamba (320 lbs), endosulfan (2,500 lbs), ethion (11,000 lbs), malathion (24,000 lbs), parathion (5,000 lbs), and phorate (11,000 lbs). Median concentrations and values for total dissolved solids, alkalinity, sodium adsorption ratio, and hardness in the Vale project area were greater than 1.5 times those values observed in the Owyhee project area or at other Snake River locations. During irrigation (August 1990), total dissolved solids, alkalinity, sodium adsorption ratio, and hardness values increased in a downstream manner. Constituent values at drainwater sites generally were comparable to concentrations below the irrigated ureas in the Owyhee and Vale project areas. The trace elements arsenic, boron, copper, molybdenum, vanadium, and zinc were detected in most water samples; cadmium, chromium, lead, and selenium were detected in some samples at concentrations generally near the analytical reporting limit; mercury was not detected in any samples. In some water samples, concentrations of arsenic, boron, cadmium, copper, and lead exceeded State or Federal water-quality standards or criteria. Most trace elements in bottom sediment were detected at concentrations within the expected 95-percent baseline range for soils from the Western United States. Concentrations that exceeded the 95-percent baseline range for study area soils were: (1) arsenic and lead in one sample from a site in the Vale project area; (2) mercury, lead, and tin in one sample from a site in the Snake River system; (3) manganese in two samples from two sites in the Snake River system; and (4) manganese from one sample from a site in the Vale project area. Fifteen pesticides and metabolites were detected in whole-water samples collected from sites in the study area. DDT, plus its metabolites (DDE and DDD), dieldrin, endrin, 2,4-D, dicamba, and dacthal were detected in samples collected from seven or more sites. Other pesticides detected included chlorpyrifos, endosulfan, ethion, malathion, parathion, phorate, and lindane. Most of the detected pesticide concentrations generally were largest in drainwater and at the most downstream sampling locations in the Owyhee and Vale project areas. Concentrations exceeded water-quality criteria established for the protection of freshwater aquatic life in 86 percent of the whole-water samples analyzed for DDT plus its metabolites, 71 percent of the dieldrin samples, 14 percent of the endrin samples, and 10 percent of the parathion samples. Eight pesticides and

Water-Resources Investigations Report↗