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Jeffrey E. Lovich

Publications and source records attributed to Jeffrey E. Lovich.

At least 19 recordsLinked to original sources
USGS2026

Abundant ticks but limited Borrelia spp. pathogens in Mojave desert tortoise habitat

Ornithodoros ticks, a genus of soft ticks in the family Argasidae, occur worldwide including throughout deserts in the Southwestern United States. In the Mojave Desert, Ornithodoros parkeri and O. turicata are common ectoparasites of Mojave desert tortoises ( Gopherus agassizii ). These two tick species are vectors of Borrelia spp. that cause tick-borne relapsing fever (TBRF) in people. However, the distribution of O. parkeri and O. turicata and TBRF group Borrelia infection prevalence remain poorly known in the Mojave Desert. These ticks are commonly found in desert tortoise burrows. In this study, 1165 ticks were collected in the Mojave Desert, 1164 of those ticks were identified as belonging to the genus Ornithodoros, while the remaining tick was an Otobius species. We used morphologic characteristics and molecular genetic analysis to identify ticks as O. parkeri and O. turicata . Twenty-two of the 1165 tick samples tested positive for TBRF group Borrelia, five of which could be sequenced and were identified as Borrelia turicatae . This study sheds light on the distributions of tick species and pathogens in an understudied ecosystem, the Mojave Desert, and identifies group Borrelia as a potential risk factor in Mojave desert tortoise habitat.

California, Nevada↗
USGS2025

Pleistocene porcupine (Erethizontidae) records in arid southwestern North America and comparisons with the modern distribution of Erethizon dorsatum in southern California and Arizona

he 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 Pleistocene records of Erethizon for southern California, no late Pleistocene records (Rancholabrean North American Land Mammal Age [NALMA]) are known for Imperial, Inyo, Riverside, or San Bernardino Counties in southern California or in Mexico. 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.

Arizona, California↗
USGS2025

Comparative life history of mud turtles (genus: Kinosternon) from the North American deserts

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.

Western North American Naturalist↗
USGS2025

Short-term ecological effects of solar energy development depend on plant community, soil type, and disturbance intensity

Solar energy is rapidly growing to decarbonize the electrical grid. Maintaining ecosystem function with solar energy generation can be promoted through construction methods that minimize negative impacts on soils and vegetation. However, the disturbance created by less-impactful construction methods at utility-scale solar energy (USSE) facilities and the ecosystem responses remain relatively unknown. We monitored soils and vegetation before and after the USSE build-out to assess the short-term impacts of construction on soils and vegetation at the Gemini Solar Project in the Mojave Desert. The facility was constructed with methods intended to be less impactful than traditional techniques. Our goal was to answer three questions: (1) What are the short-term effects of construction on soils and vegetation? (2) Do construction effects vary by the initial plant community and soil type? and (3) Does disturbance intensity from construction affect soil and vegetation response? We found strong evidence that the construction of the Gemini facility increased bare soil and soil compaction, and decreased dark biocrust cover and soil stability in the short term. For every 1% increase in disturbance intensity, we found a 0.23% increase in bare soil cover and a 0.10% decrease in dark biocrust cover. Plant responses varied more than soil responses and depended on the initial plant community and soil type, with decreases in plant canopy cover highest in sandy soils dominated by creosote bush ( Larrea tridentata ) and white bursage ( Ambrosia dumosa ) shrubs. Synthesis and applications : Many impacts of USSE facility construction depend on the underlying vegetation and soils and the level of disturbance intensity. The use of less-impactful construction methods, including a combination of overland travel and drive-and-crush examined in our study, can ameliorate negative effects relative to traditional construction practices and provide a pathway to maintain ecosystem function.

Journal of Applied Ecology↗
USGS2025

Arsenic accumulation in Sonora Mud Turtles (Kinosternon sonoriense) in an unusual freshwater food web

Montezuma Well is an unusual fishless, spring-fed, desert wetland in central Arizona. Water in the wetland is naturally enriched with > 100 µg/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.

Arizona↗
USGS2025

Do bighorn sheep use desert tortoise burrow spoil piles as mineral licks in southern California?

In a previous study, bighorn sheep ( Ovis canadensis ) were periodically photographed by trail cameras when they visited desert tortoise ( Gopherus agassizii ) burrows in the San Bernardino Mountains near Palm Springs, California, USA. The authors suggested that bighorn sheep may utilize the excavated spoil material from burrows as a mineral lick. To test that supposition, we collected soil samples from the spoil piles and undisturbed surface soil up to 1 m away at two desert tortoise study sites with bighorn sheep at the aforementioned site and another nearby site. We hypothesized that sodium concentrations would be greater in spoil than in nearby surface soil samples. Common major cations were quantified in soil samples using inductively coupled plasma-mass spectrometry following microwave-assisted digestion to solubilize the fraction of elements that could become biologically or environmentally available. Mean sodium concentrations were greater in burrow spoil samples than in undisturbed soil samples at both sites, likely due to aqueous leaching of sodium from surface to subsurface soil horizons. Although we did not collect evidence of geophagy by bighorn sheep, the behavior is well known. However, trail camera photographs of bighorn sheep with their head next to the entrance of tortoise burrows suggests that they may periodically utilize sodium and other elements brought to the surface by desert tortoises that are otherwise unavailable to bighorn sheep on the surface.

California↗
USGS2024

Predicting the effects of solar energy development on plants and wildlife in the Desert Southwest, United States

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.

Renewable & Sustainable Energy Reviews (RSER)↗
USGS2024

Climate change and collapsing thermal niches of desert reptiles and amphibians: Assisted migration and acclimation rescue from extirpation

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.

Science of the Total Environment↗
USGS2024

Aspects of the demography of a relict population of southwestern pond turtles (Actinemys pallida) in a West Mojave Desert stream in California

We studied Actinemys pallida (Southwestern Pond Turtle) in Amargosa Creek, near Palmdale, CA, from 1997 to 2023. The population in the upper creek was the focus of a mark–recapture study from 1997 to 2003 during monitoring required by a road-construction project. An estimated 193 (95% CI = 142–256) turtles were present in 1997 or recruited to the upper creek population between 1997 and 2003. Total abundance and recruitment declined after 2001, coincident with the onset of a multi-decadal megadrought. Turtles in upper Amargosa Creek are presumed to be extirpated because the creek dried up in the ensuing years. As part of a separate research project, we resurveyed the lower creek at Piute Ponds on Edwards Air Force Base from 2019 to 2023. As of 2023, there was a remnant breeding population of at least 22 turtles there. We did not find any marked turtles from the upper creek in the ponds. Only 2 populations of Southwestern Pond Turtles are known to survive in the Mojave Desert, one at Piute Ponds and another in the Mojave River.

California↗
USGS2024

Determining the distribution, status, and linkages of Agassiz's desert tortoise populations in the uplands surrounding the Coachella Valley

In support of the goals of the Coachella Valley Conservation Commission and the Bureau of Land Management, we performed surveys to determine the status, distribution, demographics, and possible genetic linkages of Agassiz’s desert tortoise (Gopherus agassizii) populations within the Coachella Valley Multiple Species Habitat Conservation Plan (CVMSHCP) area during a multi-decadal megadrought. Federal, state, and numerous parcels of privately owned conservation lands in the uplands around the periphery of the Coachella Valley were surveyed. Desert tortoise distribution data collected will be used to develop a species habitat model. These data will be overlaid with location data of flammable invasive plant species to inform fuels management and invasive plant control efforts in sensitive species habitat, as well as continue to identify high quality habitat and important desert tortoise linkage areas around the Coachella Valley. We also surveyed two established G. agassizii study plots – one at the Mesa Wind Energy Facility near Palm Springs, California and one at the Boyd Deep Canyon Desert Research Center. At those locations, we used resurveys and radio telemetry to assess habitat use, demography, and population status. We also used camera trapping at Deep Canyon to observe tortoise activities and behaviors in an unusual low elevation tortoise habitat.

California↗
USGS2023

High female desert tortoise mortality in the western Sonoran Desert during California’s epic 2012–2016 drought

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.

Western Sonoran Desert↗
USGS2023

Gopherus Agassizii (Mojave Desert Tortoise). nest depredation

Nest site selection is an important determinant of clutch success and hatchling sex ratios in Gopherus agassizii, Mojave Desert tortoises (Spotila et al. 1994. Herpetol. Monogr. 8:103-116). G. agassizii lay eggs in or near the entrance of their burrows (Ennen et al. 2012. Copeia 2012:222-228) and females of both G. agassizii and G. morafkai, may reduce egg predation risk by remaining at their burrows for days or weeks after oviposition, potentially protecting them from predators (Murray et al. 1996. Herpetological Natural History 4(1):83-88., Agha et al. 2013. Southwest. Nat. 58(2):254-257). Numerous species are known or suspected predators of desert tortoise eggs, including Vulpes macrotis (kit foxes), Spilogale gracilis (western spotted skunks), Mephitis mephitis (striped skunks), Taxidea taxus (badgers), Ammospermophilus leucurus (white-tailed antelope squirrels), Lynx rufus (bobcats), Canis latrans (coyotes), Masticophis flagellum (coachwhips), and Heloderma suspectum (Gila monsters) (Ernst & Lovich 2009. Johns Hopkins University Press, Baltimore 2:827). Here we report visitation and nest depredation at a Mojave Desert tortoise nest by multiple predators, and add a new documented species, the Urocyon cinereoargenteus (gray fox), to the list of known predators on desert tortoise eggs.

Herpetological Review↗
USGS2022

Re-evaluating invasive species in degraded ecosystems: A case study of red-eared slider turtles as partial ecological analogs

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.

Discover Sustainability↗
USGS2022

Injuries and abnormalities of the southwestern pond turtle (Actinemys pallida) in the Mojave River of California

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, predation 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 exhibited 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 statistical difference in the proportion of injured and noninjured turtles between the sexes for either the 2 LHMRS sites combined 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.

Western North American Naturalist↗
USGS2021

Birds not in flight: Using camera traps to observe ground use of birds at a wind-energy facility

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.

California↗
USGS2021

Growing as slow as a turtle: Unexpected maturational differences in a small, long-lived species

Turtle body size is associated with demographic and other traits like mating success, reproductive output, maturity, and survival. As such, growth analyses are valuable for testing life history theory, demographic modeling, and conservation planning. Two important but unsettled research areas relate to growth after maturity and growth rate variation. If individuals exhibit indeterminate growth after maturity, older adults may have an advantage in fecundity, survival, or both over younger/smaller adults. Similarly, depending on how growth varies, a portion of the population may mature earlier, grow larger, or both. We used 23-years of capture-mark-recapture data to study growth and maturity in the Spotted Turtle ( Clemmys guttata ), a species suffering severe population declines and for which demographic data are needed for development of effective conservation and management strategies. There was strong support for models incorporating sex as a factor, with the interval growth model reparametrized for capture-mark-recapture data producing later mean maturation estimates than the age-based growth model. We found most individuals (94%) continued growing after maturity, but the instantaneous relative annual plastral growth rate was low. We recommend future studies examine the possible contribution of such slow, continued adult growth to fecundity and survival. Even seemingly negligible amounts of annual adult growth can have demographic consequences affecting the population vital rates for long-lived species.

PLoS ONE↗