USGS Science⌕ Search

SEARCH · USGS Science

Results for “Bird Conservation”

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 379 records · Page 21Linked to original sources
USGS2008

Riparian vegetation dynamics and evapotranspiration in the riparian corridor in the delta of the Colorado River, Mexico

Like other great desert rivers, the Colorado River in the United States and Mexico is highly regulated to provide water for human use. No water is officially allotted to support the natural ecosystems in the delta of the river in Mexico. However, precipitation is inherently variable in this watershed, and from 1981–2004, 15% of the mean annual flow of the Lower Colorado River has entered the riparian corridor below the last diversion point for water in Mexico. These flows include flood releases from US dams and much smaller administrative spills released back to the river from irrigators in the US and Mexico. These flows have germinated new cohorts of native cottonwood and willow trees and have established an active aquatic ecosystem in the riparian corridor in Mexico. We used ground and remote-sensing methods to determine the composition and fractional cover of the vegetation in the riparian corridor, its annual water consumption, and the sources of water that support the ecosystem. The study covered the period 2000–2004, a flood year followed by 4 dry years. The riparian corridor occupies 30,000 ha between flood control levees in Mexico. Annual evapotranspiration (ET), estimated by Moderate Resolution Imaging Spectrometer (MODIS) satellite imagery calibrated against moisture flux tower data, was about 1.1 m yr −1 and was fairly constant throughout the study period despite a paucity of surface flows 2001–2004. Total ET averaged 3.4×10 8 m 3 yr −1 , about 15% of Colorado River water entering Mexico from the US Surface flows could have played only a small part in supporting these high ET losses. We conclude that the riparian ET is supported mainly by the shallow regional aquifer, derived from agricultural return flows, that approaches the surface in the riparian zone. Nevertheless, surface flows are important in germinating cohorts of native trees, in washing salts from the soil and aquifer, and in providing aquatic habitat, thereby enriching the habitat value of the riparian corridor for birds and other wildlife. Conservation and water management strategies to enhance the delta habitats are discussed in light of the findings.

Journal of Environmental Management↗
USGS2023

Embedded critical material flow: The case of niobium, the United States, and China

Niobium, often classified as critical, is typically embedded within steels essential for infrastructure and transportation. Most niobium-consuming countries are import-dependent on primary stage niobium, meaning traditional material flow analysis, which often excludes critical commodities embedded within products of large-scale industries, would miss important flows in the fabrication and manufacturing stages and underestimate niobium consumption. This study presents the first dynamic (2000–2020) niobium flow analysis for two niobium-consuming, net import-dependent countries: the United States (U.S.) and China. Results demonstrate that the U.S. is import-dependent throughout all stages of the niobium flow cycle including embedded and primary flows, whereas China is only import-dependent on primary niobium. Moreover, while most U.S. imports of niobium embedded within (semi-)finished goods are consumed domestically, most niobium-containing goods manufactured in China are exported, suggesting a supply disruption would affect their economies differently. This research demonstrates the necessity of embedded flows for criticality assessments and evaluating supply restrictions.

Resources, Conservation & Recycling↗
USGS2005

Long-range movements and breeding dispersal of Prairie Falcons from southwest Idaho

From 1999–2003, we tracked movements of adult female Prairie Falcons ( Falco mexicanus ) using satellite telemetry to characterize long-range movement patterns and breeding dispersal. We radio marked 40 falcons from April–May on their nesting grounds in the Snake River Birds of Prey National Conservation Area in southwest Idaho. All falcons with functioning transmitters left the Snake River Canyon from late June through mid-July. Most headed northeast across the Continental Divide to summering areas in Montana, Alberta, Saskatchewan, and the Dakotas. Prairie Falcons stayed at their northern summer areas for 1–4 months before heading to the southern Great Plains or to southwest Idaho. The Great Plains was a key migration pathway. Important wintering areas included the Texas Panhandle and southwest Idaho. Most falcons completed their seasonal migrations within 2 weeks. Use of widely separated nesting, summering, and wintering areas appears to be a strategy to exploit seasonally abundant prey resources. Most falcons had three or fewer use areas during the nonbreeding season, and falcons showed a high degree of fidelity to their use areas during each season. At least 21 falcons returned to nest within 2.5 km of where they nested in the previous year, but one falcon moved to a new nesting area 124 km south of her previous breeding area. Prairie Falcon movements suggest large-scale connectivity of grassland and shrubsteppe landscapes throughout western North America. Conservation of Prairie Falcons must be an international effort that considers habitats used during both nesting and non-nesting seasons.

Idaho↗
USGS2025

Landscape changes and declines in Aquila chrysaetos (Golden Eagle) territory occupancy in southwestern Idaho

Rapid loss of native shrubs and expansion of invasive annual plants like cheatgrass ( Bromus tectorum ) have altered North American shrub-steppe systems across extensive areas. Predators, like Aquila chrysaetos (Golden Eagle) that forage on shrub-reliant prey, may abandon historically occupied territories or increase their territory size to cope with degraded habitat. We used a multiseason Bayesian occupancy model that accounted for imperfect detection to investigate the associations between landscape cover, fire history, conspecific neighbor density, and occupancy of 36 A. chrysaetos territories in southwestern Idaho and the Morley Nelson Snake River Birds of Prey National Conservation Area, USA from 1986 to 2022. The probability of A. chrysaetos occupancy at historically occupied territories decreased 25% from 1986 to 2022 (0.83–0.58). Once territories became vacant for 5 yr, they tended to remain vacant, suggesting that they were no longer suitable for eagles, or that no new eagles were recruiting into the population. Territory occupancy was positively associated with shrub cover ( β : 0.90, 95% CrI: 0.12 to 1.71) and negatively (albeit weakly) associated with annual herbaceous cover ( β : –0.63, 95% CrI: –1.32 to 0.05). Territories closer to other occupied territories had a lower probability of occupancy than territories with distant neighbors ( β : –3.89, 95% CrI: –4.61 to –3.14), likely because eagles compensated for degraded habitat by expanding their territories. Years since the territory last burned had a slightly positive effect on occupancy with high uncertainty and a credible interval that overlapped 0 ( β : 0.28, 95% CrI: –0.26 to 0.87). The probability of detecting eagles in an occupied territory was high (0.90) and improved in surveys conducted earlier in the day and later in the breeding season. Shrub conversion to invasive grasslands has negative bottom-up consequences on A. chrysaetos territory occupancy, which may decrease the local carrying capacity for eagles in this area.

Idaho↗
USGS2020

Wildfire and the ecological niche: Diminishing habitat suitability for an indicator species within semi‐arid ecosystems

Globally accelerating frequency and extent of wildfire threatens the persistence of specialist wildlife species through direct loss of habitat and indirect facilitation of exotic invasive species. Habitat specialists may be especially prone to rapidly changing environmental conditions because their ability to adapt lags behind the rate of habitat alteration. As a result, these populations may become increasingly susceptible to ecological traps by returning to suboptimal breeding habitats that were dramatically altered by disturbance. We demonstrate a multistage modeling approach that integrates habitat selection and survival during the key nesting life‐stage of a bird species of high conservation concern, the greater sage‐grouse ( Centrocercus urophasianus ; hereafter, sage‐grouse). We applied these spatially explicit models to a spatiotemporally robust dataset of sage‐grouse nest locations and fates across wildfire‐altered sagebrush ecosystems of the Great Basin ecoregion, western United States. Female sage‐grouse exhibited intricate habitat selection patterns that varied across regional gradients of ecological productivity among sagebrush communities, but often selected nest sites that disproportionately resulted in nest failure. For example, 23% of nests occurred in wildfire‐affected habitats characterized by reduced sagebrush cover and greater composition of invasive annual grasses. We found survival of nests was negatively associated with wildfire‐affected areas, but positively associated with higher elevations with increased ruggedness and overall shrub cover. Strong site fidelity likely drove sage‐grouse to continue nesting in habitats degraded by wildfire. Hence, increasing frequency and extent of wildfire may contribute disproportionately to reduced reproductive success by creating ecological traps that act as population sinks. Identifying such habitat mismatches between selection and survival facilitates deeper understanding of the mechanisms driving reduced geographic niche space and population decline at broad spatiotemporal scales, while guiding management actions to areas that would be most beneficial to the species.

Global Change Biology↗
USGS2001

Effective population size and genetic structure of a Piute ground squirrel (Spermophilus mollis) population

Piute ground squirrels ( Spermophilus mollis ) are distributed continuously in habitat dominated by native shrubs and perennial grasses in the Snake River Birds of Prey National Conservation Area in Idaho, U.S.A. This habitat is being fragmented and replaced by exotic annual plants, changing it to a wildfire-dominated system that provides poor habitat for ground squirrels. To assess potential effects of this fragmentation on ground squirrel populations, we combined an estimate of effective population size ( N e ) based upon a demographic study with a population genetic analysis. The study area included three subpopulations separated from each other by 8–13 km. The ratio of effective population size to census number ( N e / N ) was 0.57. Combining N e / N with dispersal distances from a radio-tracking study, we calculated that neighborhood size was 62.2 ha, which included between 204 and 480 individuals. Our population genetic analysis (based on randomly amplified polymorphic DNA (RAPD) and microsatellite markers) showed relatively low levels of genetic differentiation (Q populations 0.07–0.10) between subpopulations and no inbreeding within subpopulations ( f = 0.0003). These estimates of population subdivision translate into an effective migration rate ( N e m ) of 2.3–3.3 per year, which represents a high level of gene flow. Invasion by exotics will reduce the overall productivity of the habitat, and will lead to isolation among subpopulations if favorable habitat patches become isolated.

Canadian Journal of Zoology↗
USGS2012

Relationships between yolk androgens and nest density, laying date, and laying order in Western Burrowing Owls (Athene cunicularia hypugaea)

Increases in yolk androgens within and among avian clutches have been correlated with decreased incubation time, increased aggression within a nest, increased begging behaviour, decreased immune response, and decreased life span. Although the mechanisms that lead to variability in yolk androgens within and between clutches are not completely known, yolk androgens can be a function of both social and environmental conditions. We were interested in if and how nesting density, laying date, and laying order influenced yolk androgens in Western Burrowing Owls (Athene cunicularia hypugaea (Bonaparte, 1825)) in which nest density varies considerably. In 2006 and 2007, we used radioimmunoassay to quantify the concentrations of testosterone, 5a-dihydrotestosterone, and androstenedione in the egg yolks from one early and one latelaid egg in 47 nests of Burrowing Owls located in the Morley Nelson Snake River Birds of Prey National Conservation Area in southern Idaho. Nesting density had no detectable effect on yolk androgens. Yolk androgens varied temporally and peaked in the middle of the laying season while being low before and after this time period. Within nests, late-laid eggs had higher testosterone and dihydrotestosterone than early-laid eggs; adrostendione exhibited a similar pattern in one but not both years of our study. It is possible that the seasonal pattern in yolk androgens that we observed is related to aspects of mate quality for females or declining chances of fledging success for later nesting females, whereas rises in egg androgens between early and late eggs within clutches could reflect a mechanism to assist nestlings from late-laid eggs that hatch one to several days after their siblings to better compete for resources within the nest or promote survival in the presence of larger siblings.

Canadian Journal of Zoology↗
USGS2018

New insights into the phylogenetics and population structure of the prairie falcon (Falco mexicanus)

Background Management requires a robust understanding of between- and within-species genetic variability, however such data are still lacking in many species. For example, although multiple population genetics studies of the peregrine falcon ( Falco peregrinus ) have been conducted, no similar studies have been done of the closely-related prairie falcon ( F. mexicanus ) and it is unclear how much genetic variation and population structure exists across the species’ range. Furthermore, the phylogenetic relationship of F. mexicanus relative to other falcon species is contested. We utilized a genomics approach (i.e., genome sequencing and assembly followed by single nucleotide polymorphism genotyping) to rapidly address these gaps in knowledge. Results We sequenced the genome of a single female prairie falcon and generated a 1.17 Gb (gigabases) draft genome assembly. We generated maximum likelihood phylogenetic trees using complete mitochondrial genomes as well as nuclear protein-coding genes. This process provided evidence that F. mexicanus is an outgroup to the clade that includes the peregrine falcon and members of the subgenus Hierofalco. We annotated > 16,000 genes and almost 600,000 high-quality single nucleotide polymorphisms (SNPs) in the nuclear genome, providing the raw material for a SNP assay design featuring > 140 gene-associated markers and a molecular-sexing marker. We subsequently genotyped ~ 100 individuals from California (including the San Francisco East Bay Area, Pinnacles National Park and the Mojave Desert) and Idaho (Snake River Birds of Prey National Conservation Area). We tested for population structure and found evidence that individuals sampled in California and Idaho represent a single panmictic population. Conclusions Our study illustrates how genomic resources can rapidly shed light on genetic variability in understudied species and resolve phylogenetic relationships. Furthermore, we found evidence of a single, randomly mating population of prairie falcons across our sampling locations. Prairie falcons are highly mobile and relatively rare long-distance dispersal events may promote gene flow throughout the range. As such, California’s prairie falcons might be managed as a single population, indicating that management actions undertaken to benefit the species at the local level have the potential to influence the species as a whole.

BMC Genomics↗
USGS2011

Genetic applications in avian conservation

A fundamental need in conserving species and their habitats is defining distinct entities that range from individuals to species to ecosystems and beyond (Table 1; Ryder 1986, Moritz 1994, Mayden and Wood 1995, Haig and Avise 1996, Hazevoet 1996, Palumbi and Cipriano 1998, Hebert et al. 2004, Mace 2004, Wheeler et al. 2004, Armstrong and Ball 2005, Baker 2008, Ellis et al. 2010, Winker and Haig 2010). Rapid progression in this interdisciplinary field continues at an exponential rate; thus, periodic updates on theory, techniques, and applications are important for informing practitioners and consumers of genetic information. Here, we outline conservation topics for which genetic information can be helpful, provide examples of where genetic techniques have been used best in avian conservation, and point to current technical bottlenecks that prevent better use of genomics to resolve conservation issues related to birds. We hope this review will provide geneticists and avian ecologists with a mutually beneficial dialogue on how this integrated field can solve current and future problems.

The Auk↗
USGS2025

Combining ecological and genomic diversity surveys to inform conservation and restoration of an endangered wetland plant, soft salty bird’s-beak (Chloropyron molle ssp. molle)

Emergent tidal wetlands are declining globally as a result of sea level rise and land use change. This habitat loss can keenly affect rare plant species within wetlands, and may require restoration to meet species recovery goals related to retaining populations throughout species' ranges. Soft salty bird’s-beak ( Chloropyron molle ssp. molle ) is a federally- and state-endangered hemi-parasitic plant that occurs at the upper marsh transition zone in the San Francisco Bay–Delta, California, USA. We combined field surveys to document habitat associations and trends in abundance with genomic surveys to understand patterns of genetic structure in this rare endemic. We found that C . molle ssp. molle persisted at nine previously occupied marsh sites, although four sites (Hill Slough, MOTCO East, Fagan Marsh, and Joice Island) were smaller in population size than when surveyed in the 1990s. Additionally, twelve sites contained plots with suitable but unoccupied habitat that could be further assessed for restoration. Genomic analysis of over 40,000 single-nucleotide polymorphisms (SNPs) and 253 individuals grouped C . molle ssp. molle into six to seven regional genetic clusters with isolation by distance, and confirmed that C . molle ssp. molle is genetically distinct from adjacent populations of its closest relative ( C . molle ssp. hispidum ). The western-most C . molle ssp. molle sites of Point Pinole and Fagan Marsh were the most genetically and geographically isolated and had the lowest genome-wide diversity. Heterozygosity in sets of genes associated with tidal elevation, salinity, and annual and summer precipitation varied independently across populations. Overall, these genomic patterns indicate that selecting donor sites with similar environmental conditions and utilizing composite seeding approaches from multiple sites could allow for local adaptation to a range of possible environmental conditions. This comprehensive survey of habitat and genomic patterns can allow for the development of restoration actions and build climate-adaptation planning to help prevent the loss of a rare plant.

California↗
USGS1997

Effects of drought and prolonged winter on Townsend's ground squirrel demography in shrubsteppe habitats

During a mark–recapture study of Townsend's ground squirrels ( Spermophilus townsendii ) on 20 sites in the Snake River Birds of Prey National Conservation Area, Idaho, in 1991 through 1994, 4407 animals were marked in 17639 capture events. This study of differences in population dynamics of Townsend's ground squirrels among habitats spanned a drought near the extreme of the 130-yr record, followed by prolonged winter conditions. Townsend's ground squirrels have a short active season (≈4 mo) in which to reproduce and store fat for overwintering. Their food consists largely of succulent grasses and forbs in this dry shrubsteppe and grassland habitat. The drought in the latter half of the 1992 active season produced early drying of Sandberg's bluegrass ( Poa secunda ) and was associated with low adult and juvenile body masses prior to immergence into estivation/hibernation. The following prolonged winter was associated with late emergence of females in 1993. Early-season body masses of adults were low in 1993 relative to 1992, whereas percentage of body fat in males was relatively high. These weather patterns in spring 1992 and winter 1993 also resulted in reduced adult persistence through the ≈7-mo inactive period, especially for adult females, and near-zero persistence of >1200 juveniles. Consequently, densities of Townsend's ground squirrels across the 20 livetrap sites declined. The demographic effects of drought and prolonged winter lasted at least through the subsequent breeding season. Adult females that survived these weather extremes produced fewer emergent young per female than did adult females prior to the event. Prior to the drought/prolonged winter, yearling female body masses were higher than, or indistinguishable from, those of adults. Females produced in 1993 had lower body masses as yearlings than did adult females. Demographic response to the drought and prolonged winter varied with habitat; ground squirrels in sagebrush habitat showed less decline in persistence and density and produced more young per female during the next active season following the drought (1993) than did ground squirrels in grassland habitat, where densities had been significantly higher prior to the drought and prolonged winter. Studies involving habitat comparisons of animal demography should always be placed in the context of long-term weather patterns, because habitat quality rankings based on density, reproduction, and survival may differ with environmental conditions. Physiological effects of environmental “crunches” on consumers may persist beyond the period of influence on food resources, reducing reproductive success and growth rates of future offspring.

Idaho↗
USGS1999

Long-term prairie falcon population changes in relation to prey abundance, weather, land uses, and habitat conditions

We studied a nesting population of Prairie Falcons ( Falco mexicanus ) in the Snake River Birds of Prey National Conservation Area (NCA) from 1974-1997 to identify factors that influence abundance and reproduction. Our sampling period included two major droughts and associated crashes in Townsend's ground squirrel ( Spermophilus townsendii ) populations. The number of Prairie Falcon pairs found on long-term survey segments declined significantly from 1976-1997. Early declines were most severe at the eastern end of the NCA, where fires and agriculture have changed native shrubsteppe habitat. More recent declines occurred in the portion of canyon near the Orchard Training Area (OTA), where the Idaho Army National Guard conducts artillery firing and tank maneuvers. Overall Prairie Falcon reproductive rates were tied closely to annual indexes of ground squirrel abundance, but precipitation before and during the breeding season was related inversely to some measures of reproduction. Most reproductive parameters showed no significant trends over time, but during the 1990s, nesting success and productivity were lower in the stretch of canyon near the OTA than in adjacent areas. Extensive shrub loss, by itself, did not explain the pattern of declines in abundance and reproduction that we observed. Recent military training activities likely have interacted with fire and livestock grazing to create less than favorable foraging opportunities for Prairie Falcons in a large part of the NCA. To maintain Prairie Falcon populations in the NCA, managers should suppress wildfires, restore native plant communities, and regulate potentially incompatible land uses.

The Condor↗
USGS1998

Influence of habitat on behavior of Towndsend's ground squirrels (Spermophilus townsendii)

Trade-offs between foraging and predator avoidance may affect an animal's survival and reproduction. These trade-offs may be influenced by differences in vegetative cover, especially if foraging profitability and predation risk differ among habitats. We examined above-ground activity of Townsend's ground squirrels ( Spermophilus townsendii ) in four habitats in the Snake River Birds of Prey National Conservation Area in southwestern Idaho to determine if behavior of ground squirrels varied among habitats, and we assessed factors that might affect perceived predation risk (i.e. predator detectability, predation pressure, population density). The proportion of time spent in vigilance by ground squirrels in winterfat ( Krascheninnikovia lanata ) and mosaic habitats of winterfat-sagebrush ( Artemisia tridentata ) was more than twice that of ground squirrels in burned and unburned sagebrush habitats. We found no evidence for the “many-eyes” hypothesis as an explanation for differences in vigilance among habitats. Instead, environmental heterogeneity, especially vegetation structure, likely influenced activity budgets of ground squirrels. Differences in vigilance may have been caused by differences in predator detectability and refuge availability, because ground squirrels in the winterfat and mosaic habitats also spent more time in upright vigilant postures than ground squirrels in burned-sagebrush or sagebrush habitats. Such postures may enhance predator detection in low-growing winterfat.

Journal of Mammalogy↗
USGS1997

Distribution of black-tailed jackrabbit habitat determined by GIS in southwestern Idaho

We developed a multivariate description of black-tailed jackrabbit (Lepus californicus) habitat associations from Geographical Information Systems (GIS) signatures surrounding known jackrabbit locations in the Snake River Birds of Prey National Conservation Area (NCA), in southwestern Idaho. Habitat associations were determined for characteristics within a 1-km radius (approx home range size) of jackrabbits sighted on night spotlight surveys conducted from 1987 through 1995. Predictive habitat variables were number of shrub, agriculture, and hydrography cells, mean and standard deviation of shrub patch size, habitat richness, and a measure of spatial heterogeneity. In winter, jackrabbits used smaller and less variable sizes of shrub patches and areas of higher spatial heterogeneity when compared to summer observations (P < 0.05). During the low population phase, jackrabbits also used agricultural regions more during winter than summer. The association with agricultural regions was emphasized spatially in a GIS map contrasting winter and summer periods. Multivariate habitat means (P < 0.001), but not individual GIS variables (P > 0.05), differed significantly between high and low population phase. We used the Mahalanobis distance statistic to rank all 50-m cells in a 440,000-ha region relative to the multivariate mean habitat vector. On verification surveys to test predicted models, we sighted jackrabbits in areas ranked close to the mean habitat vector. Areas burned by large-scale fires between 1980 and 1992 or in an area repeatedly burned by military training activities had greater Mahalanobis distances from the mean habitat vector than unburned areas and were less likely to contain habitats used by jackrabbits.

Journal of Wildlife Management↗
USGS1997

Use of burrow entrances to indicate densities of Townsend's ground squirrels

Counts of burrow entrances have been positively correlated with densities of semi-fossorial rodents and used as an index of densities. We evaluated their effectiveness in indexing densities of Townsend's ground squirrels ( Spermophilus townsendii ) in the Snake River Birds of Prey National Conservation Area (SRBOPNCA), Idaho, by comparing burrow entrance densities to densities of ground squirrels estimated from livetrapping in 2 consecutive years over which squirrel populations declined by >75%. We did not detect a consistent relation between burrow entrance counts and ground squirrel density estimates within or among habitat types. Scatter plots indicated that burrow entrances had little predictive power at intermediate densities. Burrow entrance counts did not reflect the magnitude of a between-year density decline. Repeated counts of entrances late in the squirrels' active season varied in a manner that would be difficult to use for calibration of transects sampled only once during this period. Annual persistence of burrow entrances varied between habitats. Trained observers were inconsistent in assigning active-inactive status to entrances. We recommend that burrow entrance counts not be used as measures or indices of ground squirrel densities in shrubsteppe habitats, and that the method be verified thoroughly before being used in other habitats.

Idaho↗
USGS1997

Spatial use and habitat selection of golden eagles in southwestern Idaho

We measured spatial use and habitat selection of radio-tagged Golden Eagles ( Aquila chrysaetos ) at eight to nine territories each year from 1992 to 1994 in the Snake River Birds of Prey National Conservation Area. Use of space did not vary between years or sexes, but did vary among seasons (home ranges and travel distances were larger during the nonbreeding than during the breeding season) and among individuals. Home ranges were large, ranging from 190 to 8,330 ha during the breeding season and from 1,370 to 170,000 ha outside of the breeding season, but activity was concentrated in small core areas of 30 to 1,535 ha and 485 to 6,380 ha during the breeding and nonbreeding seasons, respectively. Eagles selected shrub habitats and avoided disturbed areas, grasslands, and agriculture. This resulted in selection for habitat likely to contain their principal prey, black-tailed jackrabbits ( Lepus californicus ). Individuals with home ranges in extensive shrubland (n = 3) did not select for shrubs in the placement of their core areas or foraging points, but individuals in highly fragmented or dispersed shrublands (n = 5) concentrated their activities and foraged preferentially in jackrabbit habitats (i.e. areas with abundant and large shrub patches). As home ranges expanded outside of the breeding season, individuals selected jackrabbit habitats within their range. Shrubland fragmentation should be minimized so that remaining shrub patches are large enough to support jackrabbits.

The Auk↗
USGS2015

Quantifying and predicting fuels and the effects of reduction treatments along successional and invasion gradients in sagebrush habitats

Sagebrush shrubland ecosystems in the Great Basin are prime examples of how altered successional trajectories can create dynamic fuel conditions and, thus, increase uncertainty about fire risk and behavior. Although fire is a natural disturbance in sagebrush, post-fire environments are highly susceptible to conversion to an invasive grass-fire regime (often referred to as a “grass-fire cycle”). After fire, native shrub-steppe plants are often slow to regenerate, whereas nonnative annuals, especially cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae), can establish quickly and outcompete native species. Once fire-prone annuals become established, fire occurrences increase, further promoting dominance of nonnative species. The invasive grass-fire regime also alters nutrient and hydrologic cycles, pushing ecosystems beyond ecological thresholds toward steady-state, fire-prone, nonnative communities. These changes affect millions of hectares in the Great Basin and increase fire risk, decrease habitat quality and biodiversity, accelerate soil erosion, and degrade rangeland resources for livestock production. In many sagebrush landscapes, constantly changing plant communities and fuel conditions hinder attempts by land managers to predict and control fire behavior, restore native communities, and provide ecosystem services (e.g., forage production for livestock). We investigated successional and nonnative plant invasion states and associated fuel loads in degraded sagebrush habitat in a focal study area, the Morley Nelson Snake River Birds of Prey National Conservation Area (hereafter the NCA), in the Snake River Plain Ecoregion of southern Idaho. We expanded our inference by comparing our findings to similar data collected throughout seven major land resource areas (MLRAs) across the Great Basin (JFSP Project “Fire Rehabilitation Effectiveness: A Chronosequence Approach for the Great Basin” [09-S-02-1]). 4 We used a combination of field-sampling, experimental treatments, and remotely sensed data to address the following questions: (1) How do fuel loads change along gradients of succession and invasion in sagebrush ecological sites? (2) How do fuel reduction treatments influence fuels in invaded areas formerly dominated by sagebrush? (3) How do fuel loads vary across landscapes and which remote sensing techniques are effective for characterizing them?

Idaho↗
USGS2018

Fuels guide and database for intact and invaded big sagebrush (Artemisia tridentata) ecological sites—User manual

The Fuels Guide and Database (FGD) is intended to provide fuel loading and vegetation information for big sagebrush ( Artemisia tridentata ) ecological sites in the Morley Nelson Snake River Birds of Prey National Conservation Area (hereinafter the NCA) in southern Idaho. Sagebrush ecosystems in the NCA and throughout much of the Great Basin are highly influenced by non-native plants that alter successional trajectories and promote frequent wildfires, especially due to fine-fuel loadings that are highly variable over time and space. These dynamic fuel conditions can increase uncertainty when attempting to project fire risk and fire behavior. The FGD was developed to help quantify and assess these dynamic fuel loadings, and it provides access to fuels data across a range of conditions, from relatively intact sagebrush-bunchgrass communities to degraded communities dominated by nonnative annual grasses and forbs. The FGD can be queried for a variety of environmental conditions, and it provides tabular data, reports, and photographic records of fuels based on user queries. This report describes the FGD, including overall data content and data-collection methods, as well as instructions for installing and using the database.

Data Series↗