Conservation planning and biodiversity management require information on landscape connectivity across a range of spatial scales from individual home ranges to large regions. Reduction in due changes land use or development is expected act synergistically with alterations habitat mosaic configuration arising climate change. We illustrate multiscale framework aid conservation prioritization the context changing climate. Our approach, which builds upon strengths multiple methods, including...

Abstract A key assumption in species distribution modeling (SDM) with presence‐background (PB) methods is that sampling of occurrence localities unbiased and any bias proportional to the background environmental covariates. This rarely met when SDM practitioners rely on federated museum records from natural history collections for geo‐located occurrences due inherent found these collections. We use a simulation approach explore effectiveness three developed account PB frameworks. Two careful...

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 12:167-177 (2010) - DOI: https://doi.org/10.3354/esr00298 Contribution Theme Section 'Responses of animals habitat alteration' Effects subsidized predators, resource variability, and human population density on desert tortoise populations in Mojave Desert, USA Todd C. Esque1,*, Ken E. Nussear1, K. Kristina Drake1,...

Abstract We translocated 120 Agassiz's desert tortoises to 5 sites in Nevada and Utah evaluate the effects of translocation on tortoise survivorship, reproduction, habitat use. Translocation included several elevations, extended with vegetation assemblages not typically associated order explore possibility moving animals upper elevation areas. measured movements resident at each site. Survivorship was significantly different between within among sites, survivorship greater overall during...

Many of the threats to persistence populations sensitive species have physiological or pathological mechanisms, and those mechanisms are best understood through inherently integrative discipline ecology. The desert tortoise was listed under Endangered Species Act largely due a newly recognized upper respiratory disease thought cause mortality in individuals severe declines populations. Numerous hypotheses about involve acquisition nutrients, its connection stress disease. nutritional wisdom...

Hypolithic microbes, primarily cyanobacteria, inhabit the highly specialized microhabitats under translucent rocks in extreme environments. Here we report findings from hypolithic cyanobacteria found three types of (quartz, prehnite, agate) a semiarid region tropical Australia. We investigated photosynthetic responses cyanobacterial communities to light, temperature and moisture laboratory, measured microclimatic variables soil field over an annual cycle. also used molecular techniques...

Abstract Aim We explored lineage diversification within desert‐dwelling fauna. Our goals were (1) to determine whether phylogenetic lineages and population expansions consistent with younger P leistocene climate fluctuation hypotheses or much older events predicted by pre‐ vicariance hypotheses, (2) assess concordance in spatial patterns of genetic divergence diversity among species (3) identify regional evolutionary hotspots their conservation status. Location Mojave, C olorado, S onoran D...

Abstract Wildlife managers consider animal translocation a means of increasing the viability local population. However, augmentation may disrupt existing resident disease dynamics and initiate an outbreak that would effectively offset any advantages have achieved. This paper examines fundamental concepts ecology identifies conditions will increase likelihood following translocation. We highlight importance susceptibility to infection, population size connectivity – characteristic likely...

Abstract Wildlife translocation is increasingly used to mitigate disturbances animals or habitat due human activities, yet little known about the extent which translocating causes stress. To understand relationship between physiological stress and translocation, we conducted a multiyear study (2007–2009) using population of desert tortoises ( G opherus agassizii ) near F ort I rwin, C alifornia. Blood samples were collected from adult in three treatment groups (resident, translocated...

Most directly transmitted infections require some form of close contact between infectious and susceptible hosts to spread. Often disease models assume contacts are equal use mean field estimates transmission probability for all interactions with hosts. Such methods may inaccurately describe when differ substantially in their ability cause infection. Understanding this variation risk be critical properly model manage diseases. In study, we investigate how varying exposure key understanding...

The relative importance of abiotic and biotic factors in determining species distributions has long been interest to ecologists but is often difficult assess due the lack spatially temporally robust occurrence records. Furthermore, locating places where potentially highly competitive co‐occur may be challenging would provide critical knowledge into effects competition on ranges. We built distribution models for two closely related small mammals ( Neotoma ) that are largely parapatric along...

ABSTRACT Describing future habitat for sensitive species can be helpful in planning conservation efforts to ensure persistence under new climatic conditions. The Gila monster ( Heloderma suspectum ) is an iconic lizard of the southwestern United States. northernmost range monsters Mojave Desert, area experiencing rapid human population growth and urban sprawl. To understand current potential we fit ensemble distribution models using known locations environmental variables important species'...

Summary Recent elevated temperatures and prolonged droughts in many already water‐limited regions throughout the world, including southwestern United States, are likely to intensify according future climate‐model projections. This warming drying can negatively affect perennial vegetation lead degradation of ecosystem properties. To better understand these detrimental effects, we formulate a conceptual model dryland vulnerability climate change that integrates hypotheses on how plant species...

Abstract Habitat disturbance from development, resource extraction, off‐road vehicle use, and energy development ranks highly among threats to desert systems worldwide. In the Mojave Desert, United States, these disturbances have promoted establishment of nonnative plants, so that native grasses forbs are now intermixed with, or been replaced by invasive, Mediterranean grasses. This shift in plant composition has altered food availability for Desert tortoises ( Gopherus agassizii ), a...

Summary In spite of growing reliance on translocations in wildlife conservation, translocation efficacy remains inconsistent. One factor that can contribute to failed is releasing animals into poor‐quality or otherwise inadequate habitat. Here, we used a targeted approach test the relationship habitat features post‐translocation dispersal and survival juvenile Mojave desert tortoises Gopherus agassizii . We selected three characteristics – rodent burrows, substrate texture (prevalence size...

Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high are conservation targets, identifying containing genetic divergence among populations may be important to protect future evolutionary potential. When multiple co-distributed show spatial overlap in divergence, these can considered hotspots. We mapped population structure 17 animal across Mojave Desert, USA. analyzed concurrence located 10 diversity, or both species. These were...

This research examined the onset, duration, and termination of hibernation in Desert Tortoises (Gopherus agassizii) over several years at multiple sites northeastern part their geographic range, recorded temperatures experienced by tortoises during winter hibernation. The timing differed among years. Environmental cues acting short-term did not appear to influence period. Different individual entered as many 44 days fall emerged from 49 spring. range variation indicates a weak best exogenous...

First posted May 19, 2009 For additional information, contact: Director, Western Ecological Research CenterU.S. Geological Survey3020 State University Drive EastModoc Hall, Room 3006Sacramento, CA 95819 Habitat modeling is an important tool used to simulate the potential distribution of a species for variety basic and applied questions. The desert tortoise (Gopherus agassizii) federally listed threatened in Mojave Desert parts Sonoran California, Nevada, Utah, Arizona. Land managers this...

ABSTRACT Wildfires burned 24,254 ha of critical habitat designated for the recovery threatened Mojave desert tortoise ( Gopherus agassizii ) in southern Nevada during 2005. The proliferation non‐native annual grasses has increased wildfire frequency and extent recent decades continues to accelerate conversion across Desert. Immediate changes vegetation are expected reduce quality habitat, yet whether tortoises will use recovering differently from intact unburned is unknown. We compared...

Abstract Background Preserving corridors for movement and gene flow among populations can assist in the recovery of threatened endangered species. As human activity continues to fragment habitats, characterizing natural is important establishing maintaining connectivity within anthropogenic development matrix. The Mojave desert tortoise ( Gopherus agassizii ) a species occupying variety habitats Colorado Deserts. Desert tortoises have been referred as corridor-dwellers, understanding how...

Abstract Species conservation plans frequently rely on information that spans political and administrative boundaries, especially when predictions are needed of future habitat under climate change; however, most species their requisite often limited in geographical scope. Moreover, dispersal constraints for concern not incorporated into distribution models, which can result overly optimistic habitat. We used a standard modeling approach across suite 23 taxa amphibians reptiles the North...