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The accuracy of posttranslocation population monitoring methods is critical to assessing long-term success in translocation programs. Translocation can produce unique challenges to monitoring efforts; therefore, it is important to understand the flexibility and robustness of commonly used monitoring methods. In Florida, USA, thousands of gopher tortoises Gopherus polyphemus have been, and continue to be, translocated from development sites to permitted recipient sites. These recipient sites create a broad range of potential monitoring scenarios due to variability in soft-release strategies, habitat conditions, and population demographics. Line transect distance sampling is an effective method for monitoring natural tortoise populations, but it is currently untested for translocated populations. We therefore produced 3,024 individual-based, spatially explicit scenarios of translocated tortoise populations that differed in recipient site and tortoise population properties, based on real-world examples, literature review, and expert opinion. We virtually sampled simulated tortoise populations by using line transect distance sampling methods and built a Bayesian hierarchical model to estimate the population density for each simulation, which incorporated individual-level covariates (i.e., burrow width and burrow occupancy). Line transect distance sampling was largely appropriate for the conditions that typify gopher tortoise recipient sites, particularly when detection probability on the transect lines was greater than or equal to 0.85. Designing the layout of transects relative to the orientation of soft-release pens, to avoid possible sampling biases that lead to extreme outliers in estimates of tortoise densities, resulted in more accurate population estimates. We also suggest that use of individual-level covariates, applied using a Bayesian framework as demonstrated in our study, may improve the applicability of line transect distance sampling surveys in a variety of contexts and that simulation can be a powerful tool for assessing survey design in complex sampling situations. [ABSTRACT FROM AUTHOR]

An inherent challenge in managing rare or cryptic species is data deficiency. For this reason, ancillary data is a potentially valuable resource for generating key population estimates for priority species. We compiled ancillary commensal data collected between 1982 and 2020 during surveys of gopher tortoise (Gopherus polyphemus) burrows to estimate the terrestrial distribution of gopher frogs (Rana capito) from potential breeding wetlands. Gopher frogs were detected in gopher tortoise burrows 30‒3,879 m from identified wetlands. A global model of all records from all sites indicated that the probability of a gopher frog residing in a gopher tortoise burrow declined with increasing distance from a wetland. This pattern also held for 4 of 5 sites with a sufficient number of gopher frog detections to model independently. Based on the full data set, we estimated that 50%, 90%, and 99% of gopher frog observations occurred within 392 m, 1,019 m, and 2,752 m of the nearest wetland, respectively. Our results indicate a higher proportion of gopher frogs emigrate longer distances from wetlands than was previously reported using other methods, such as radio‐telemetry. This information can directly assist with management decisions, notably the spatial extent for application of habitat management surrounding breeding wetlands. More generally, this study illustrates the capacity of ancillary data to fill data deficiencies for a rare and cryptic species and highlights the importance of these data. [ABSTRACT FROM AUTHOR]

Line‐transect distance sampling (LTDS) surveys are commonly used to estimate abundance of animals or objects. In terrestrial LTDS surveys of gopher tortoise (Gopherus polyphemus) burrows, the presence of ground‐level vegetation substantially decreases detection of burrows of all sizes, but no field or analytical methods exist to control for spatially heterogeneous vegetation obstruction as a source of variation in detection. We propose the addition of a simple measurement of ground‐level vegetation that serves as a covariate for the detection function. We present a Bayesian hierarchical model in which covariates burrow width and nearby vegetation height help to account for detection bias and improve precision of estimated density. We investigate the performance of this covariate by simulation and by using real LTDS data collected before and after application of prescribed fire. We collected data in 2018 at the Jones Center at Ichauway in Newton, Georgia, USA. Across all simulations, our model including both covariates produced the most accurate density point estimates of any of the models tested. For our case study, our Bayesian model with vegetation covariates tended to produce similar estimates of density before and after burns. Our study indicates that any level of spatial variation in vegetation obstruction decreases detection of burrows and may lead to underestimation in population size (≤68%) and proportion of individuals with small burrow sizes (≤32%) when not considered during analysis. Our work is extensible to other terrestrial sampling efforts where systematic measurement of a spatially distributed obstructing feature is feasible during the LTDS survey. [ABSTRACT FROM AUTHOR]

Understanding risk factors associated with reintroductions is important for making informed decisions within an adaptive framework. Biosecurity measures minimizing the risk of the introduction or spread of transmissible diseases are a priority when considering the release of captive-reared wildlife. Eastern indigo snake (EIS; Drymarchon couperi) reintroductions have been occurring in Alabama since 2010 and in Florida since 2017. During this effort the pathogen Cryptosporidium serpentis was detected, affecting several of the captive breeding snakes. Infected snakes were quarantined and removed from breeding efforts, which reduced snakes available for the reintroduction projects. To make informed management decisions about future reintroduction strategies, 155 free-ranging snakes were sampled at the two release sites and a third site in Georgia to evaluate the natural occurrence of C. serpentis. Additionally, 72 free-ranging EIS and other species incidentally encountered throughout the EIS range were tested opportunistically. All snakes sampled at the three focal sites tested negative, but one opportunistically tested EIS from South Florida tested positive. These results indicate that C. serpentis is present in the environment in at least one location, but at low levels. Our results suggest that, pending additional surveillance, C. serpentispositive snakes should not be included in reintroduction efforts, and that maintaining a high level of biosecurity is important in captive breeding programs. [ABSTRACT FROM AUTHOR]

ABSTRACT Terrestrial movements of turtles are of interest due to the conservation implications for this imperiled group and the general lack of information on this topic, particularly in wide-ranging species. [...]

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The gopher frog Lithobates capito is one of the most terrestrial frogs in the southeastern United States and often inhabits gopher tortoise burrows Gopherus polyphemus outside of the breeding season. Gopher frog populations have declined, and the species is under review for listing as threatened or endangered under the U.S. Endangered Species Act. Much of our knowledge on the status of gopher frogs is based on detections of larvae at breeding wetlands, which can be challenging because of environmental variability and provides no information on the terrestrial life stages of the species. Therefore, an alternative method is called for. We recorded observations of gopher frogs during gopher tortoise surveys at four conservation lands in Florida and used line-transect distance sampling to estimate frog abundance. We also recorded burrow size, incidence of frog co-occupancy with tortoises, and distance from frog-occupied burrows to breeding wetlands. We observed 274 gopher frogs in 1,097 tortoise burrows at the four sites. The proportion of burrows occupied by gopher frogs among sites ranged from 0.17 to 0.25. Gopher frog abundance in tortoise burrows was 742 (512–1,076 95% CL) at Etoniah Creek State Forest, 465 (352–615) at Ft. White Wildlife Environmental Area, 411 (283–595) at Mike Roess Gold Head Branch State Park, and 134 (97–186) at Watermelon Pond Wildlife Environmental Area. We observed up to four frogs in a single burrow. The proportion of frogs detected in burrows occupied by a gopher tortoise ranged from 0.46 to 0.79 among sites, and overall, gopher frogs preferred burrows occupied by tortoises over unoccupied burrows (χ2 = 15.875; df = 3; P = 0.001). Gopher frogs used burrows from 7 to 43 cm in width; mean width of frog-occupied burrows did not differ from that of unoccupied burrows (F1,3 = 0.049, P = 0.825). Distance from frog-occupied tortoise burrows to the nearest breeding wetland ranged from 141 to 3,402 m. Our data on gopher frogs collected in conjunction with gopher tortoise monitoring efforts using line-transect distance sampling and burrow cameras provided novel information on frog abundance in their terrestrial habitat and required no additional effort. However, the extent to which frogs use tortoise burrows relative to other available refuges (small mammal burrows, stumps, or other structures) is unknown; thus, our estimates should be considered conservative. We suggest that terrestrial abundance estimates for gopher frogs can complement efforts to monitor breeding activity to provide a more comprehensive means of monitoring population trends in this cryptic species. [ABSTRACT FROM AUTHOR]

Ecological stoichiometry provides a framework to predict how animals regulate nutritional balances within their tissue and, as a result, how animal biomass affects ecosystem processes through nutrient cycling. However, most interspecific and developmental stoichiometric studies in animals focus on invertebrates, and the few vertebrate studies are largely fish‐centric. Larval anurans are ideal vertebrates to test predictions of developmental and interspecific stoichiometry as they undergo a complex development, exhibit broad arrays of life‐history traits, and can constitute high animal biomass in wetlands, implying major roles in wetland nutrient storage and cycling. We examined (1) patterns of body stoichiometry across larval developmental stages within multiple anuran species, (2) whether key predictors of stoichiometric change, specifically body size, developmental period, and breeding season, influence interspecific stoichiometric variation, and (3) natural magnitudes and fluctuations of larval anuran nutrient storage in geographically isolated wetlands (GIWs). We measured carbon (C), nitrogen (N), and phosphorus (P) tissue content in larval anurans across five developmental stages within 11 species collected from four GIWs to examine patterns of developmental and interspecific stoichiometry. Within species, we found broad developmental stoichiometric patterns in which later developmental stages were lower in %N, but higher in %P than earlier stages. Patterns in %C were inconsistent but were generally lower in later stages, while tissue C:N ratios increased, and C:P and N:P decreased in later developmental stages. Interspecific stoichiometric variation was partially explained by body size and developmental period which positively affected %C and C:N ratios. We observed spatial and temporal fluctuations in species‐specific biomass which dictated nutrient storage patterns within larval anuran assemblages, though stoichiometric identity played a major role. Our estimated magnitudes of larval anuran areal nutrient storage also greatly exceeded that of other wetland fauna with the maximum estimated areal P storage reaching over 200 times that of a similar‐density co‐occurring invertebrate group. These results highlight stoichiometric patterns of development and interspecific variation in a diverse group of amphibians while providing critical baseline information for elucidating the role of anurans in wetland nutrient dynamics. [ABSTRACT FROM AUTHOR]