Obtaining reliable estimates of population density is critical to effective wildlife conservation and management. Densities of Mojave desert tortoises (Gopherus agassizii) traditionally have been estimated using line-distance sampling, but the burrowing behavior of tortoises poses issues for estimation with that design-based method. Spatial capture-recapture (SCR) models are flexible hierarchical models for estimating spatially explicit population density and other demographic parameters from spatially and temporally replicated detection data; yet, few studies have explored SCR utility for estimating desert tortoise densities. We conducted a 4-day transect-based, search-area survey on a pilot demography plot within the restricted-access South Range of Naval Air Weapons Station China Lake (NAWSCL) in the western Mojave Desert to obtain tortoise detection data and applied SCR models to estimate spatially explicit sex- and age class-specific densities of desert tortoises. We obtained 99 detections of 24 individual tortoises (6 adult F, 4 adult M, 14 juveniles) during the 4-day survey. Explicitly accounting for the spatiotemporally varying survey effort, SCR model-averaged estimated mean tortoise density across the entire 2.53-km2 parameter estimation area was 18.53 tortoises/km2 (95% CI = 12.36–27.77; CV = 0.21). The estimated age class ratio was skewed towards juveniles (64% juveniles: 36% adults), whereas the adult sex ratio was female-biased (61% females: 39% males); corresponding densities were 11.86 juveniles/km2 (95% CI = 7.91–17.77), 4.08 adult females/km2 (95% CI = 2.72–6.11), and 2.59 adult males/km2 (95% CI = 1.73–3.89). Our study provides NAWSCL with preliminary local tortoise demographic estimates that can be used for long-term monitoring by establishing additional regional demographic monitoring sites. Additionally, we suggest further application of SCR models for estimating desert tortoise densities, as well as direct comparisons with traditional tortoise density estimation approaches, to update or improve density estimates and inform continued tortoise recovery.

The desperate state of our world's natural systems increasingly requires drastic, large-scale actions to restore ecological function. Yosemite National Park is undertaking the largest project of its kind to restore a Sierra Nevada meadow, in a site occupied by Northwestern pond turtles (Actinemys marmorata) which are proposed for federal listing. Meadow restoration is being achieved through extensive heavy equipment work to fill occupied erosion gullies in the stream channel, creating unique challenges in protecting this declining freshwater turtle. We utilized pre-project trapping, interdisciplinary planning for retention and construction of long-term aquatic habitats, radio telemetry of high value-turtles, small scale translocations, manual clearance surveys, and canine clearance surveys to achieve our objectives. We will describe our multi-pronged approach to developing informed turtle protection and impact minimization measures, and report “lessons learned” following the last 2 years of project implementation, in the intention that our highlights may help others involved in large-scale habitat manipulations (such as consulting biologists and land managers) to achieve favorable outcomes for freshwater turtles.

The terrestrial habitat of the semi-aquatic southwestern pond turtle (Actinemys pallida) remains under-researched compared to its aquatic environment. This study documents the nesting and estivation movements of A. pallida in southern California from 2009 to 2024, along with a potential hatchling migration. Utilizing radio telemetry on transmittered turtles and observations of naturally encountered individuals, we measured distances from aquatic habitats to terrestrial movement locations. These behaviors are critical for population survival and provide essential insights for the conservation and management of A. pallida. Understanding the terrestrial movements and habitat preferences of this cryptic species is vital for effective conservation strategies.

Legacy hardrock mining in California has left more than 200,000 abandoned mine features (e.g., shafts, adits, prospecting pits) throughout the state, with a larger concentration in California’s deserts. These mine features pose a hazard to humans and the environment if not remediated, but these features have also become habitat for wildlife. The federally - and state - listed Mojave Desert Tortoise (Gopherus agassizii) use abandoned mine adits for refuge, as well as being found alive and dead in mine shafts and in pits as shallow as two feet deep. The California Department of Conservation’s Abandoned Mine Lands Unit (AMLU) collaborates with partner agencies to protect people from abandoned mine hazards in California, while preserving mining history and wildlife habitat. Human safety and bat habitat are often the primary considerations when planning closures; however, desert tortoises should also be considered, especially within their critical habitat. Using information from inventory and wildlife surveys, land managers can modify bat gates and fences within the species’ range. Modifications such as tortoise “doors” in mine gates, filling shallow prospecting pits, and the addition of tortoise fencing at mine shafts are some initial steps to allow continued habitation and protect this listed species, respectively.

The Northwestern pond turtle (NWPT), Actinemys marmorata, is a species listed by the Departments of Fish and Wildlife in the 3 western states and is currently pending listing by the USFW. Little is known about the specific habitat conditions required for reproductive success and how land affected by intensive agriculture may alter these conditions. To address the existing knowledge gaps, Sonoma State University has initiated a study focused on a population of NWPT inhabiting stock ponds on a working cattle ranch in Alameda County, California. Our preliminary studies during the 2024 summer nesting season identified 20 successful nests and documented multiple failed nesting attempts by gravid females. Our data show that nest site characteristics at our site vary when compared to similar studies done at other sites in California. This research will provide critical new insights into the nesting behavior of this population of NWPT, and has the potential to inform land managers in California to be better equipped to evaluate current grazing and land use practices, protect and maintain wetlands, and assess the impacts of agricultural practices on native herpetofauna.

In the spirit of this year's theme entreating us to slow down our fast-paced lives to celebrate the species we love and the mysteries that surrounds them, I am excited to debut a nature documentary more than ten years in the making. Western Pond Turtles - Between Two Shells marks the culmination of my attempt to spend less time capturing turtles and more time observing and recording the natural history of these remarkable species. By simply waiting and watching, I've been fortunate enough to witness western pond turtles nesting within arm's reach, laying eggs, courtship, and more. And some of it, I've been lucky enough to capture on film. I invite you to join me on this journey between two shells...