The Mojave desert tortoise Gopherus agassizii experienced population declines during recent decades, which have persisted despite its designation as a federally protected species. A small number of populations were monitored with mark-recapture methods starting in the 1970s, but inconsistent sampling resulted in challenges estimating the range of factors influencing survival. Large amounts of tortoise telemetry data were collected in recent decades, providing an alternative source for survival estimation. Here, we describe an integrated, spatially explicit, analysis that combined mark-recapture (3923 tortoises, 35 sites, 1977-2022) and telemetry (2858 tortoises, 22 sites, 1988-2022) datasets to estimate variation in survival across tortoise populations. We produced robust estimates of annual survival conditioned on climate-related covariates and compared results to non-integrated known-fate and mark-recapture models. Integration allowed for estimation of effects on survival not recovered by non-integrated models, including higher survival of males than females, lower survival of juveniles and subadults than adults, and a positive effect of total precipitation from 2 prior winters and active seasons. The integrated analysis estimated permanent emigration rate as the difference between both true survival (via telemetry data) and apparent survival (via capture-recapture data). Annual emigration probability was ~5% in 1 km2 plots and decreased with increasing plot size. Our results demonstrate the strength of leveraging multiple data sources in describing historical demographic rates and identifying relationships with covariates that have delayed effects on survival. Our modeling framework could be used to examine the effects of additional factors on tortoise survival and resulting population dynamics.

The North American porcupine (Erethizon dorsatum) is widely distributed throughout many ecosystems on the continent from northern Mexico to the Arctic Ocean, except for the southeastern portion of the United States. Habitats include the arid Desert Southwest region where modern records are generally sparse. The paleogeographic range in the Desert Southwest is not unlike the modern distribution of Erethizon, with some exceptions. Although there are early PleisMexico. This is surprising given late-Pleistocene records in Arizona, Nevada, and New Mexico and modern records from southern California and Mexico. Pleistocene habitats for porcupines were similar to those occupied today, just at different elevations due to differing climates. Modern preferred habitats in the Desert Southwest include conifer-clad high-elevation areas and associated pinyon pine/juniper belts, and occasionally riparian corridors in desert environments. The overall rarity of porcupines today in arid parts of the Desert Southwest is likely due to the combination of increasing aridity in the region during the Holocene, past persecution by humans, and increasing predator populations.

Management units (MUs) are important to conserving species of conservation concern. Although the MU definition is simple (i.e., a demographically independent population), identifying MUs in practice is difficult because investigators must choose a recent (i.e., last few generations) migration rate threshold. One suggested MU criterion is m < 0.10, where m is the proportion of a subpopulation comprised of recent migrants. However, a more recent study found that m as low as 0.02 (i.e., one migrant per generation) can cause estimates of linkage disequilibrium effective population size ( N eLD) to underestimate a subpopulation's true N e. Here, we used genome-wide SNP data obtained from 40 tortoises and an MU criterion of m < 0.02 to define MUs within the Colorado Desert population of the Mojave desert tortoise ( Gopherus agassizii )—an endangered species in California and a species in the USA protected under the Endangered Species Act. Based on our results we defined the Mesa and Deep Canyon subpopulations as MUs even though the latter received at least two recent immigrants. Migrant(s) from the Shavers Valley subpopulation were likely translocated by humans, whereas migrant(s) from the Mesa subpopulation could have been human-mediated or natural migrants. Initial analyses suggest that the Shavers Valley subpopulation may be an MU, but our low sample size renders this result inconclusive. The local N e estimates for the Mesa and Deep Canyon subpopulations—5 and 13 adults, respectively—are below the minimum sizes according to the 50/500 rule and thus they may be candidates for genetic rescue. ### Competing Interest Statement The authors have declared no competing interest. Coachella Valley Conservation Commission, UCR-23121344, 21ZDTAA11821 The Living Desert

. - A full understanding of life-history patterns and their evolution in turtles has been impeded by data gaps, particularly for reproductive data, for most species. With the goal of enabling a better understanding of turtle life-history variation and its correlates, we amassed a data set of traits for 2466 populations (captive and wild) of 323 species of turtles, including members of all 14 turtle families and 90% of the 357 extant, currently recognized species. For each turtle population, the data set includes general locality and latitude, habitat, diet, female carapace length and body mass, age at maturity, mean clutch size, egg shell type, mean egg length, width and mass, clutch mass, relative clutch mass (clutch mass/gravid body mass), clutch frequency, longevity, and data sources. The data set still lacks reproductive data of any kind for 34 species but represents the most complete assemblage of turtle life-history information to date.

The warm deserts of North America are characterized by diverse environments that include the transition zone between tropical and temperate regions on the continent. This vast region includes the Sonoran and Chihuahuan deserts, which have different precipitation regimes and are composed of different floras and faunas, separated by the Cochise Filter Barrier. Inhabiting these deserts are 7 mud turtles (representing 4 separate clades within the genus Kinosternon), and we compared their basic ecology, life history, and estivation time to test for variation between deserts. We used phylogenetic comparative methods to correlate the life history traits with environmental variables (temperature and precipitation) to test for variation between deserts. Life history strategies (clutch size, egg size, and reproductive phenology) of mud turtles were similar across both deserts, with negative correlations of clutch size and age of maturity with both aridity and temperature variables. Maximum estivation time was correlated with the seasonality of each included locality. Overall, life history strategies were quite similar, with small local specializations to avoid high temperatures and periodic lack of water. From a population ecology perspective, populations showed varied sex ratios biased toward males or females, along with different population structure among populations and species. However, most published studies lacked data for hatchlings. Phylogenetic signal is high in traits related to body size, including sexual size dimorphism. Overall, mud turtles from the southwest deserts are adapted to regional seasonality and precipitation regimes, with minor adjustments to fit local conditions.

Utility-scale solar energy (USSE) is rapidly expanding and expected to compose the largest source of renewable-generated electricity in the United States and globally over the coming decades. Lands in the hot Desert Southwest (Chihuahuan, Mojave, Sonoran, and San Joaquin Deserts) are increasingly selected for USSE development because of their high solar irradiance. The Desert Southwest supports high biodiversity and provides many ecosystem services but is vulnerable to USSE disturbance and simultaneous stress from aridification and other growing land-use pressures. In this review, a framework is presented for predicting the effects of USSE development on plants and wildlife by linking disturbance types associated with USSE construction and operation to the traits and response strategies of species and guilds. Case studies from representative Desert Southwest species and guilds of conservation concern are used to: review known effects of USSE, predict unknown effects with the trait-based framework, and discuss mitigation strategies. This framework predicts that species with trait plasticity and broad ecological niches will be capable of exploiting USSE development, while species with specific habitat requirements and narrow niches will be more vulnerable. Opportunities for mitigation during development and operation that may lessen these effects are identified. This work is intended to inform USSE management decision-making and long-term planning, as well as encourage new research to test predicted effects and responses.

In the first range-wide population viability model for the northwestern and southwestern pond turtles (Actinemys marmorata and Actinemys pallida, respectively), a stage-based population projection matrix was assembled with 3 life stages: hatchling, juvenile, and adult. Vital rates were defined using biologically appropriate statistical distributions, with additional parametric uncertainty included for the adult survival parameter. A triple-loop stochastic simulation model was built around a population viability analysis to project pond turtle populations into the future. Initial abundance was calculated using available historical presence data and remotely sensed landscape condition metrics. A negative binomial regression was used to predict the relationship between abundance, habitat area, and human modification. Populations of pond turtles are dominated by adult individuals, so we applied a nonstable stage distribution to initial abundance values. Initial abundances of analysis units were variable across the species' ranges, but all populations declined precipitously in the population projections. By the end of the century, the mean range-wide probability of extinction was 44.3% for the northwestern species and 57.8% for the southwestern species. Consistent with other long-lived chelonian species, population growth rate was most sensitive to adult survival, indicating that where possible, conservation efforts focusing on increasing or maintaining adult survival would benefit the species. Elasticity analysis indicated a bet-hedging life history strategy where long- term reproductive output is maximized through longevity, small clutches, and frequent reproductive bouts in the face of highly variable juvenile survival. The population dynamics presented here indicate that efforts to bolster adult survival would be most beneficial in terms of long- term population viability, which can inform targeted research and management. The feasibility of such efforts is an important consideration in conservation management for these longlived species.

We studied the reproductive cycle of male and female Mauremys leprosa in central Morocco. The cycle for males starts in the spring with warming temperatures and the beginning of the dry-season with testicular enlargement and a decrease in epididimydes size accompanied by sperm production. The epididymis contains sperm mainly in winter, spring and summer. Females exhibited follicular enlargement from November reaching a peak in February when a maximum follicle size of 38.5 mm was observed. Ovulation appears to begin in April or May and oviductal eggs were present in our samples from April – July. Suspected mating activity occurred from January – March when environmental temperatures were lowest and the wet-season peaked. Sexual activity was coincident with the onset of maximum storage of sperm in the epididymis. The overall reproductive cycle of this species is similar to that of other Temperate Zone turtles with the exception that mating occurs in the winter, not in the spring and fall. Winter mating may be a response to the wet-season Mediterranean climates. Rain connects isolated pools in ephemeral rivers and streams in Morocco that form during the dry season, thus providing greater opportunities for access to mates.

Recent climate change should result in expansion of species to northern or high elevation range margins, and contraction at southern and low elevation margins in the northern hemisphere, because of local extirpations or range shifts or both. We combined museum occurrence records from both the continental U.S. and Mexico with a new eco-physiological model of extinction developed for lizard families of the world to predict the distributions of 30 desert -endemic reptile and amphibian species under climate change scenarios. The model predicts that 38 % of local populations will go extinct in the next 50 years, across all 30 species. However, extinctions may be attenuated in forested sites and by the presence of montane environments in contemporary ranges. Of the 30 species, three were at very high risk of extinction as a result of their thermal limits being exceeded, which illustrates the predictive value of ecophysiological modeling approaches for conservation studies. In tandem with global strategies of limiting CO2 emissions, we propose urgent regional management strategies for existing and new reserves that are targeted at three species: Barred Tiger Salamander (Ambystomatidae: Ambystoma mavortium stebbinsi), Desert Short -horned Lizard (Phrynosomatidae: Phrynosoma ornatissimum), and Morafka's Desert Tortoise (Testudinidae: Gopherus morafkai), which face a high risk of extinction by 2070. These strategies focus on assisted migration and preservation within climatic refugia, such as high -elevation and forested habitats. We forecast where new reserves should be established by merging our model of extinction risk with gap analysis. We also highlight that acclimation (i.e., phenotypic plasticity) could ameliorate risk of extinction but is rarely included in ecophysiological models. We use Ambystoma salamanders to show how acclimation can be incorporated into such models of extinction risk.

Montezuma Well is an unusual fi shless, spring-fed, desert wetland in central Arizona. Water in the wetland is naturally enriched with > 100 mu g/l dissolved geogenic arsenic (As) and supports a simple aquatic food web dominated by a small number of endemic invertebrate species that achieve high abundances. Previous studies of As among various environmental compartments and organisms in Montezuma Well did not include omnivorous Sonora Mud turtles ( Kinosternon sonoriense) despite their potential importance in the As cycle by virtue of their substantial biomass and role as top predators. We measured As concentrations in water, sediment, and organisms (macrophytes, amphipods, insects, leeches, and turtles) representing a range of trophic levels in order to document the importance of turtles at the apex of the Montezuma Well food web and in the As cycle. Concentrations of As in turtles varied according to tissue type. The greatest values (up to 26.77 mg/kg dry weight) were in the scutes of 1 of our oldest turtles (31.5 yrs). These elevated concentrations may be due to the affinity of As to react with sulfur in the keratin of scutes, and therefore might reflect duration of exposure in long-lived turtles. Although As concentrations generally tend to decrease when moving up to higher trophic levels in a food web, our results were different. Relatively elevated concentrations reported in sediments by us and a previous study declined in plant samples as expected. Amphipod concentrations increased but then decreased again in 3 of their invertebrate predators. Arsenic concentrations in endemic leeches were extremely elevated with a mean value of 72.2 mg/kg. The mean concentration of As in turtles was 7.08 mg/kg across tissue types and was greater than the plants or invertebrates they eat, with the notable exception of leeches, which have been proposed to be part of their diet.

Previous articleNext article No AccessEcologySalleyland: Wildlife Adventures in Swamps, Sandhills, and Forests. By Whit Gibbons. Tuscaloosa (Alabama): University of Alabama Press. $22.95 (paper). xiv + 166 p.; ill.; index. ISBN: 978-0-8173-6064-1 (pb); 978-0-8173-9426-4 (eb). 2022.Jeffrey E. LovichJeffrey E. LovichSouthwest Biological Science Center, U.S. Geological Survey, Flagstaff, Arizona Search for more articles by this author PDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 98, Number 1March 2023 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/723924 Views: 3Total views on this site For permission to reuse, please contact [email protected]PDF download Crossref reports no articles citing this article.

We conducted population surveys for desert tortoises Gopherus agassizii at 2 nearby sites in the western Sonoran Desert of California, USA, from 2015-2018, during the driest ongoing 22 yr period (2000-2021) in the southwestern USA in over 1200 yr. We hypothesized that drought-induced mortality would be female-biased due to water and energy losses attributable to egg production during protracted periods of resource limitation. At the higher-elevation, cooler, wetter Cottonwood site from 2015-2016, the sex ratio of live adult tortoises was biased toward males and the sex ratio of tortoises estimated to have died during the intensified drought conditions from 2012-2016 was essentially even. At the lower-elevation, warmer, drier Orocopia site from 2017-2018, the sex ratio of live adult tortoises was biased toward males and the sex ratio of tortoises with estimated times of death from 2012-2016 was biased toward females. High female mortality at the Orocopia site may have resulted from the interaction of drought effects and the bet-hedging reproductive strategy of tortoises wherein they continue to produce clutches of eggs in drought years. Annual reproductive output results in an estimated loss of up to 13.5% of female tortoise body mass including over 0.20 l of water. Combined with dehydration during severe droughts, these losses may compromise their ability to survive droughts lasting more than 2 yr. The low tortoise density and high mortality of females observed may reflect reduced survival of tortoises near the southern edge of their range due to climate change, including protracted and intensified droughts.

The southwestern pond turtle (Actinemys pallida) is a semiaquatic turtle that occasionally spends time on land to bask, oviposit, make intermittent overland movements, and overwinter in terrestrial locations. Use of both aquatic and terrestrial environments exposes semiaquatic turtles to increased risk of injury or mortality from floods, pre-dation attempts, and other environmental hazards (e.g., human activities such as vehicle strikes, etc.). We collected injury and morphological abnormality data from adult turtles at 3 study sites along the length of the Mojave River in San Bernardino County, California: 1 site on the upper half of the Mojave River (hereafter known as UHMRS) and 2 sites each on the lower half of the Mojave River (hereafter known as LHMRS). The studies were conducted when turtles were most active between May and October 1998-1999 and again from April to September 2016-2019. A total of 84 A. pallida were captured among all sites and all years. Seventeen percent (n = 8) of the turtles captured at UHMRS exhib-ited shell abnormalities (natural variations in shell or bone morphology). Injuries (damage inflicted by force to the shell or body) occurred in 68% (n = 26) of captured turtles at both the LHMRS sites combined and 78% (n = 36) of turtles captured at the UHMRS alone. A total of 74% (n = 62) of turtles had injuries at all sites combined. There was no statisti-cal difference in the proportion of injured and noninjured turtles between the sexes for either the 2 LHMRS sites com-bined or the UHMRS. Mean carapace length was not significantly different between injured and noninjured turtles for these same sites. Injuries occurred in the majority of captured turtles at all sites and may be an indicator of the extent of threats facing these turtles.

Abstract Context. Camera trapping is increasingly used to collect information on wildlife occurrence and behaviour remotely. Not only does the technique provide insights into habitat use by species of interest, it also gathers information on non-target species. Aims. We implemented ground-based camera trapping to investigate the behaviours of ground-dwelling birds, a technique that has largely been unutilised for studying birds, especially in wind-energy facilities. Methods. We used camera traps to monitor activities of Agassiz’s desert tortoises (Gopherus agassizii) at their self-constructed burrows in a wind-energy facility near Palm Springs, California, USA. While doing so, we collected data on numerous burrow commensals, including birds. Key results. Monitoring from late spring to mid-autumn in one year showed regular use of tortoise burrows and the immediate area by 12 species of birds, especially passerines. The most abundant species, as indicated by the number of photographs, but not necessarily individuals, was the rock wren (Salpinctes obsoletus), with a total of 1499 events. Birds appeared to use the interior or proximate vicinity of burrows for gathering nesting material, displaying, feeding, dust bathing and other activities. Of the bird species observed, 10 are known to be occasional casualties of turbine-blade strikes. The minimum known-age of a burrow had a positive relationship with bird counts. Conclusions. Using camera traps focused at ground level can be a useful tool in avian conservation efforts because it is an effective technique for measuring bird presence, activity and behaviour in altered habitats such as wind farms, especially for those species that are low flyers or ground dwellers. Implications. Acquiring data over the long term by using ground-based monitoring with camera traps could add to our understanding of avian behaviour and habitat use in relation to wind-energy infrastructure and operations, and help determine the vulnerability of avifauna that utilise the area.

Exotic species are often vilified as “bad” without consideration of the potential they have for contributing to ecological functions in degraded ecosystems. The red-eared slider turtle (RES) has been disparaged as one of the worst invasive species. Based on this review, we suggest that RES contribute some ecosystem functions in urban wetlands comparable to those provided by the native turtles they sometimes dominate or replace. While we do not advocate for releases outside their native range, or into natural environments, in this review, we examine the case for the RES to be considered potentially beneficial in heavily human-altered and degraded ecosystems where native turtles struggle or fail to persist. After reviewing the ecosystem functions RESs are known to provide, we conclude that in many modified environments the RES is a partial ecological analog to native turtles and removing them may obviate the ecological benefits they provide. We also suggest research avenues to better understand the role of RESs in heavily modified wetlands.