Blanding's Turtles Research Articles

Emydomyces testavorans Surveillance in Multiple Free-Ranging Terrestrial and Aquatic Chelonian Species in Illinois, USA.

The order Onygenales contains multiple fungal pathogens that affect free-ranging and zoo-housed reptilian species. Emydomyces testavorans, an onygenalean fungus associated with skin and shell disease, has been sporadically detected in aquatic chelonians. Because of the recent discovery of this organism, little is known about its prevalence in free-ranging chelonians. The objective of this study was to perform surveillance for E. testavorans in six free-ranging aquatic and terrestrial chelonian species in Illinois, USA: Blanding's turtles (n=437; Emydoidea blandingii), painted turtles (n=199; Chrysemys picta), common snapping turtles (n=35; Chelydra serpentina), red-eared sliders (n=62; RES; Trachemys scripta elegans), eastern box turtles (n=73; Terrapene carolina carolina) and ornate box turtles (n=29; Terrapene ornata). Combined cloacal-oral swabs (COSs) or shell (carapace and plastron surfaces) swabs were collected from 2019 to 2021 and tested for E. testavorans using quantitative PCR. The PCR detected E. testavorans in COSs of an adult male, subadult female, and juvenile male Blanding's turtle (0.6%; 95% confidence interval [CI], 0.2-1.9%) and a shell swab from an adult female RES (1.6%; 95% CI, 0-8.7%). Shell lesions consistent with E. testavorans infection were present in two of the positive Blanding's turtles. These results document the rarity of this pathogen on the landscape in Illinois. Additional studies should determine this pathogen's impact on individuals and clarify its significance for conservation efforts of Blanding's turtle, in which E. testavorans has not been reported previously.

Post-Release Survivorship in a New Population of Blanding's Turtles Established Using Headstarted and Directly Released Turtles

Post-Release Survivorship in a New Population of Blanding's Turtles Established Using Headstarted and Directly Released Turtles

Recovery of a Blanding's Turtle Population through Nest Protection and Headstarting

Recovery of a Blanding's Turtle Population through Nest Protection and Headstarting

Variable effects of captivity on microbiomes in populations of IUCN-endangered Blanding's turtles (Emydoidea blandingii).

Microbiome composition is increasingly considered in species reintroduction efforts and may influence survival and reproductive success. Many turtle species are threatened by anthropogenic pressures and are frequently raised in captivity for reintroduction efforts, yet little is known about turtle microbiome composition in either wild or captive settings. Here, we investigated trends in microbiome composition of captive and wild IUCN-endangered Blanding's turtles (Emydoidea blandingii). We amplified and sequenced the V4 region of the 16S rDNA locus from plastron, cloaca, and water samples of wild E. blandingii adults and two populations of captive E. blandingii juveniles being raised for headstarting. Plastron, cloaca, and water-associated microbiomes differed strongly from each other and were highly variable among captive sites and between captive and wild sites. Across plastron, cloaca, and water-associated microbial communities, microbial diversity changed over time, but not in a predictable direction between captive sites. Plastron beta diversity correlated with growth rate in captive samples, indicating that external microbiomes may correlate with individual fitness. Our results indicate that external and internal microbiomes vary between captive and wild turtles and may reflect differences in fitness of captive-raised individuals.

Bedrock morphology influences rock barrens turtle nesting habitat energy dynamics.

Energy absorption and flow through a nest is an important aspect of embryonic development in many reptile species including turtles. To date, few studies have explicitly attempted to quantify the energy flow through turtle nests, opting instead for the simplified approach offered by temperature index models. However, the quantification of the energy can provide an explicit abiotic link that can link biological models to biometeorological and ecohydrological processes and models. We investigated the energy flow through turtle nests occupying different bedrock morphologies within a Canadian Shield Rock Barren landscape, in Ontario, Canada. The taxons studied were Spotted Turtle (Clemmys guttata), Midland Painted Turtle (Chrysemys picta marginata), and Blanding's Turtle (Emydoidea blandingii). Nest temperature and soil moisture were measured in 2018 and 2019 using sensors placed in the soil adjacent to 12 turtle nest cavities. Three main rock morphologies were identified for each nest location, Crevice, Ledge, and Flat types, that are in order of decreasing bedrock percentage contact with the nest site. Ground heat flux and change in heat storage were determined using the calorimetric method for each nest, while the direction of energy flux between the atmosphere and the underlying rock was also determined. The Crevice nest morphology experienced the lowest ground heat flux on average (1.56 × 10-1 W m-2) and lowest cumulative heat storage (230 MJ) compared to the Flat (440 MJ) and Ledge (331 MJ) nests. However, over the diurnal cycle, large heat gains by Flat nests were mostly balanced out by nighttime heat losses. While Crevice nests saw the lowest daily heat storage gains, they experienced much lower heat losses over the evening period compared to the other nest types. Furthermore, we found that 59% of the energy is directed from the underlying bedrock into the Crevice nest, highlighting the importance of the bedrock in controlling thermal dynamics in the turtle nesting habitat. The lower variability in energy parameters for Crevice nest types can be attributed to higher amounts of nest-to-bedrock contact, compared to the flat nest types. Our results indicate that Crevice morphology may be ideal for turtles nesting at their northern limits because minimal heat loss during the evening can result in a more stable thermal incubation environment. Future conservation and habitat restoration efforts should consider the importance of bedrock morphology and prioritize the protection of Crevice nest sites. Furthermore, this work highlights important opportunities for potential interdisciplinary work between ecologists, climatologists, biologists, and hydrologists, specifically the integration of ecohydrological and biological models. This work also underscores the potential uncertainty of climate change impacts on turtle egg hatching success and nest sex ratios.

Evaluating Different Methods for Determining Erythrocyte Sedimentation Rate in Free-Living Blanding's Turtles (Emydoidea blandingii).

Characterizing host factors affecting individual health can be important in the conservation of many chelonians, including the Blanding's turtle (Emydoidea blandingii). However, many routine clinical pathology tests do not reliably detect differences in health status in reptiles. The erythrocyte sedimentation rate (ESR) has been shown to characterize inflammation in many species, including tortoises, and may be useful in assessing Blanding's turtles. The purpose of our study was to evaluate two methods of ESR measurement in free-ranging Blanding's turtles. Sixty Blanding's turtles captured at two sites in Illinois received a complete physical examination, and blood was collected for determination of packed cell volume, total solids, and ESR with both microhematocrit tubes and commercial kits (Winpette). Method agreement was assessed with Passing-Bablok regression. Associations between ESR and demographic, environmental, and health factors were determined by linear regression. The microhematocrit tube method proportionately overestimated ESR compared with the Winpette. With the use of both measurement methods, ESR was significantly different between study sites, higher in adult Blanding's turtles, and higher in females that were gravid compared with those that were not. ESR was also negatively associated with packed cell volume. ESR values in Blanding's turtles are comparable to other reptiles, and although microhematocrit tube and Winpette results are not interchangeable, their associations with biological predictors are similar, and either method has the potential to be used with separate reference intervals to assess turtles for inflammatory conditions.

Effects of release method on the survival, somatic growth, and body condition of headstarted turtles

AbstractHeadstarting involves ex situ rearing of vulnerable life stages, then releasing individuals into the wild once they are larger and less vulnerable to predation. Sometimes, headstarted animals display underdeveloped behaviors that may lead to an acclimation period of reduced survival and growth after release. Using data from a 6‐year headstarting program, we tested whether the early release condition affected survival, body condition, and somatic growth rate in 2 groups of headstarted Blanding's turtles (Emydoidea blandingii) released into Rouge National Urban Park (RNUP) in Toronto, Ontario, Canada. The first group included turtles released directly into the wild (i.e., hard release). The second group included turtles released into an in situ enclosure in which individuals remained for a week without food supplementation before being fully released into the wild (i.e., delayed release). Release condition did not affect survival or growth rate. In the delayed‐release group, body condition initially declined rapidly and remained low for up to 1 year after release. Given the lack of wild juveniles in RNUP, we compared body condition of headstarted turtles at various time points since release to similar‐sized wild juveniles from 2 other Ontario populations, one from Algonquin Provincial Park (APP) and one near Lake Erie (LE). Body condition of headstarted turtles was similar to those of wild APP turtles regardless of release method, and higher than those of wild LE turtles. Our results indicate that delayed release did not improve post‐release outcomes for headstarted turtles in an urban landscape and headstarted turtles sustain similar health metrics as wild turtles.

Demographic evidence that development is not compatible with sustainability in semi‐urban freshwater turtles

AbstractBalancing urban development with environmental sustainability is a major challenge that is increasingly recognized in planning decisions. Urban development proposals are often approved with the expectation that deleterious impacts on native species will be constrained, but this assumption is rarely tested over sufficient timelines to confirm its validity for long‐lived, at‐risk species. We tracked changes in Blanding's turtle (Emydoidea blandingii) habitat availability and demography over 10 years near Ottawa, ON, Canada, to determine whether urban development and associated mitigation measures were sufficient to ensure long‐term population persistence. Suitable turtle habitat declined by 10% during the study, and wetland corridors were essentially lost. Habitat loss coincided with a marked reduction in adult turtle apparent survival, resulting in a 70% decline in population size. Adult females experienced the greatest decline, and despite wildlife fencing and culvert placement as conditions of project approval, turtle road mortality likely was the primary cause of the decline. Deterministic population viability analysis revealed that ~4 adult female road mortalities (of an initial 56 females) per year produced a comparable decline to that observed in our population estimates; at this rate, the population will likely breach its quasi‐extinction threshold (4 females) in under a decade. Accordingly, we infer that in our study area, approved urban development was not compatible with at‐risk turtle population viability. Our findings imply that urban development approval conditions, even when conducted in the context of seemingly robust species‐at‐risk protection, can be inadequate to ensure sustainability. We contend that if environmental sustainability is to be prioritized, urban development projects in areas occupied by at‐risk species must be subject to more stringent oversight during the planning, approval and implementation phases.

Spatial and thermal ecology of juvenile head‐started Blanding's turtles Emydoidea blandingii

Declining reptilian populations has been a growing concern over the last couple of decades. One such declining species of concern, the Blanding's turtle Emydoidea blandingii, occurs as isolated populations in North American prairie‐wetlands and is at risk of extirpation due to habitat loss and fragmentation, and increased predator (e.g. racoons, coyotes) populations due to supplemented resources in urban environments. To help mitigate declining populations, wildlife managers have invested in the conservation of this species through head‐starting (i.e. reared in ex situ) and juvenile release programs to augment wild Blanding's turtle populations. However, much of their spatial and winter/thermal ecology is understudied, and data for juveniles, and juveniles reared ex situ is especially scarce, yet this information is imperative to understanding shortfalls and improving head‐starting efforts in the future. In spring 2016 (RR2016) and 2017 (RR2017) we released a cohort (n = 12 each year) of head‐started juvenile Blanding's turtles equipped with radio transmitters and temperature dataloggers into a prairie‐wetland in the greater Chicago region, North America. Using ground‐based radio telemetry, we determined seasonal movement areas (SMAs; spring, summer and fall) and annual home ranges (AHRs) for both RR2016 and RR2017 cohorts via kernel density (KD) estimates. We also investigated the thermal characteristics of overwintering for both juvenile cohorts. We found that SMAs for the RR2016 cohort, but not for the RR2017 cohort, significantly differed across seasons for most SMA estimators. We also found that juveniles in both cohorts not only survived overwintering, but also displayed similar overwintering phenology (i.e. initiation: October–November; termination: April) and temperature variation as Blanding's turtles adults in other studies. Overall, our results indicate that head‐started juvenile Blanding's turtles may be able to acclimatize quickly to their natural environment post‐release. Our study provides evidence to the efficacy of well‐developed head‐starting programs that aim to augment and preserve imperiled turtle populations.

Growth and Survival of Wild and Head-Started Blanding's Turtles (Emydoidea blandingii)

Blanding's Turtles (International Union for Conservation of Nature [IUCN] Endangered) are long-lived reptiles with delayed sexual maturity. Anthropogenic landscape changes have increased threats to juvenile turtles, resulting in unnaturally low recruitment. Head-starting has become a popular conservation strategy that aims to increase juvenile recruitment by avoiding the increased predation of the vulnerable nest and hatchling age class. However, there is still debate about whether or not it is an effective management tool. Assessments of head-starting are becoming more prevalent, but long-term studies are needed to critically evaluate the success of such interventions. In particular, information is needed on how head-starts fare compared to wild-hatched turtles. The Lake County Forest Preserve District (LCFPD) in northeastern Illinois initiated a long-term capture–mark–recapture project in 2004. As of 2018, 127 wild-hatched juvenile turtles had been captured (59 of which had been captured in multiple years) and 148 adult turtles had been captured (116 of which had been recaptured in multiple years). Since 2010, LCFPD has released 491 headstarted turtles during the year following hatching, 138 of which have been recaptured during successive years. We used von Bertalanffy growth analysis to compare growth trajectories and Cormack-Jolly-Seber modeling techniques to compare survival rates of wild-hatched and head-started turtles. At release, head-started turtles were about the size of two-year-old wild-hatched turtles and grew in parallel to their wild-hatched counterparts. The top-ranked survival models demonstrated that survival increased with age for both wild-hatched (71–98%) and head-started turtles (63–90%), with overlapping confidence intervals. These results suggest that head-started juveniles perform similarly to like-aged wild-hatched juveniles despite head-starts having attained greater body size. We estimated adult survival to be 95% with an environmental variance of 0.0011 and stable or positive population growth (k). Although the success of head-starting cannot be fully assessed until turtles are recruited into the adult population and successfully reproduce, patterns of head-start growth and survival provide positive intermediate measures of success. Our estimation of juvenile and adult survival, along with other demographic information from this population, will provide for more accurate population projections that will aid in evaluating conservation strategies for this population and potentially for Blanding's Turtles elsewhere.

Effects of Artificial Ultraviolet B Radiation on Plasma 25-Hydroxyvitamin D3 Concentrations in Juvenile Blanding's Turtles (Emydoidea blandingii)

Abstract Vitamin D is an essential hormone that can be acquired via the diet, exposure to ultraviolet B (UVB) radiation, or a combination of both. Studies in reptiles suggest that the acquisition of vitamin D can vary between species; thus, species-specific evidence-based research should be pursued to develop appropriate husbandry recommendations. The objective of this study was to determine whether artificial UVB could be used to increase circulating 25-hydroxyvitamin D3 (25-OHD3) concentrations in juvenile Blanding's turtles (Emydoidea blandingii). Sixteen juvenile Blanding's turtles from an ongoing headstart program at the DuPage County Forest Preservation District (Wheaton, IL, USA) were used for this study. The Blanding's turtles were randomly divided into two groups of eight by using a random number generator. The treatment group was exposed to light from three compact UVB 23-W fluorescent bulbs 12 h/day for 6 months, whereas the control group was not provided supplemental UVB lighting. Bulbs were placed 15.2 cm (6 in) from the water surface. A radiometer was used to measure UVB radiation 15.2 cm from the bulb surface on days 0 and 180. Blood samples were collected at a single time point (day 180) to measure 25-OHD3 concentrations. There was a significant difference (P < 0.001) in plasma 25-OHD3 concentrations between groups, with 25-OHD3 concentrations being 5.5 times higher in the UVB group than in the controls. Based on the results of this study, we recommend exposing juvenile Blanding's turtles to artificial UVB as part of their standard care.

Comparing Life Histories of the Shortest-Lived Turtle Known (Chicken Turtles, Deirochelys reticularia) with Long-Lived Blanding's Turtles (Emydoidea blandingii)

Evolutionary theories predict major differences in life-history trait values of long- and short-lived organisms. Such comparisons have not been possible for chelonians because no short-lived turtle was known until research revealed that chicken turtles (Deirochelys reticularia; DR) have a maximum longevity of 21 yrs. Life-history trait values of DR females are 1) age at maturity of females = 5–6 yrs; 2) clutches per season = 1.6; 3) annual fecundity = 6–8 female eggs per female; 4) average juvenile survivorship from age 1 to maturity = 0.60; and 5) low average annual adult survivorship = 0.66. We compared DR with the very long-lived Blanding's turtles (Emydoidea blandingii; EB) in Michigan. Over 14 yrs with no mortality (the minimum age at maturity of EB), the maximum potential fecundity produced by a single female embryo and her mature female offspring was 5 female eggs for EB and 1040 eggs for DR. Comparisons of life table output for approximately stable populations of DR and EB resulted in cohort generation times of 7 and 37 yrs, respectively. The life-history prediction that short-lived organisms should produce smaller offspring was not supported. Average wet mass of eggs is 10 g (8.4–11.3 g) for DR and 12 g (10–14 g) for EB; and average wet mass of hatchlings is 7.3 g (6–9 g) for DR and 9.3 g (6–13 g) for EB. Both differences are smaller than expected based on the difference in longevity. Short-lived female DR have an unusual tactic of investing in high fecundity and making substantial body size-specific investment in large eggs, which may reflect why juvenile survivorship had greater influence on population change rates than did adult survivorship. In contrast, adult survivorship had the greatest influence on population change rates of EB. Comparison of cohorts of 1000 female DR and EB hatchlings highlights the differences in life histories of short- and long-lived turtles: all DR would be dead by the time the last female EB had reached maturity at 21 yrs of age.

The emergence of imperfect philopatry and fidelity in spatially and temporally heterogeneous environments

Repeatability in habitat use - often termed site fidelity - is widespread and ubiquitous. Often, used habitat areas may be inherited by offspring in a phenomenon called natal philopatry, leading to intergenerational repeatability in habitat preferences. Both fidelity and philopatry may represent strategies that could optimize fitness in spatially and temporally heterogeneous environments; however, the suite of ecological factors that encourage or discourage fidelity and philopatry remain poorly understood in most taxa. While turtles (Order Testudines) exhibit both fidelity and natal philopatry when selecting nesting areas, emerging evidence suggests that nest choice may be more plastic than previously thought. However, few studies to date have attempted to explore the behavioral choices that may produce deviations from nest site fidelity and philopatry. We used a spatially-explicit, individual-based model to explore how behavioral responses to a heterogeneous landscape can generate population-level patterns of fidelity and philopatry. We demonstrate that this model can dispersal patterns inferred from behavioral and genetic data from a Blanding's Turtle (Emydoidea blandingii) population in central Wisconsin. Reduced philopatry was associated with increasing error rates in habitat discrimination, and reduced site fidelity was associated with decreasing risk tolerance. Unpredictable spatial distributions of risk increased natal philopatry but decreased site fidelity overall, suggesting that strong natal imprinting may sometimes be associated with rapid shifts in habitat preferences in unpredictable environments. Associating risk exposure with increased adult or nest mortality led to increased nest site fidelity in both cases, but with relatively weak effects on natal philopatry. We also demonstrate the utility of this model for other landscapes and species by exploring a simplified seabird system. Our model holds promise for more detailed exploration of the ecological and evolutionary factors that may give rise to fidelity and philopatry.

Night moves: nocturnal movements of endangered spotted turtles and Blanding's turtles

AbstractDiel activity patterns in animals can be diurnal (concentrated during daylight), nocturnal (concentrated during darkness), cathemeral (both daylight and darkness) or crepuscular (concentrated at twilight). Freshwater, Nearctic turtles are typically considered diurnal, apart from crepuscular or nocturnal nesting migrations by mature females. However, some crepuscular and nocturnal activity has been observed in non‐nesting freshwater turtles. There are no quantitative studies of nocturnal movements in freshwater turtles, but GPS‐tracking devices provide an opportunity to collect and archive locations for 24 h, providing the GPS antenna is exposed above water. We collected GPS locations and shell temperatures from mature spotted turtles (Clemmys guttata, n = 12) and Blanding's turtles (Emydoidea blandingii, n = 12) from May to July 2018 in southern Ontario, Canada. We compared the minimum distance moved by turtles during the day and night, and we tested previously proposed hypotheses that nocturnal movement is linked to nesting or thermoregulatory benefits. Blanding's turtle movements were primarily diurnal, but spotted turtles were cathemeral. Nocturnal activity by spotted turtles was not restricted to the nesting season and did not confer thermoregulatory benefits. We hypothesize that nocturnal exposure and movement by spotted turtles provide increased time for foraging or mate‐seeking, allowing daytime hours to be used for basking. Our study demonstrates cathemeral diel patterns in spotted turtles and quantitatively tests hypotheses about the drivers of nocturnal behaviour in freshwater turtles. Future research should use observational methods in order to better understand the purpose of nocturnal activity in Nearctic, freshwater turtles.

Multi-scale Assessment of Rock Barrens Turtle Nesting Habitat: Effects of Moisture and Temperature on Hatch Success

Understanding thermal and moisture regimes in nesting habitat is an important step in management and restoration of at-risk turtle habitat because anthropogenic stressors that affect these key properties impact hatch success. In rock barrens landscapes, freshwater turtles are known to nest in unique shallow-soil deposits in depressions in the bedrock. Our objective was to provide the first comprehensive multi-scale assessment of turtle nesting habitat in a rock barrens landscape. At the nest-site scale, we characterized nesting habitat, tested for evidence of nest-site selection by the Blanding's Turtle (Emydoidea blandingii), Spotted Turtle (Clemmys guttata), and Midland Painted Turtle (Chrysemys picta marginata), and examined the effects of nest temperature and moisture on egg hatching success. At the landscape-scale, we conducted a systematic survey across 660 ha to assess the availability of nesting habitat. Although rock barrens were the second most dominant land cover type, the availability of suitable nesting habitat with deeper soil and an open canopy was limited to 11% of the rocky outcrops and <3% of the study area. We found that shallow rock barrens nesting habitat had unique soil temperature and moisture dynamics that were linked to soil properties and bedrock morphology to provide successful incubation conditions. In particular, mean daily temperature, variance of soil saturation during incubation, and their interaction had a significant effect on egg hatching success, regardless of egg mass. There was also evidence that turtles selected sites that were warmer and drained faster than paired haphazard sites despite having other similar characteristics. Given that the loss and degradation of nesting habitat is of conservation concern for the survival and recovery of at-risk turtle species, we recommend that key management strategies should include stronger protection of critical rock barrens nesting habitat and the development of landscape-appropriate strategies for restoration and creation of nesting habitat.

Estimating Population Size of a Threatened Turtle Using Community and Citizen Science

Blanding's turtles (Emydoidea blandingii) are considered threatened or endangered throughout most of their range. A critical step in determining appropriate conservation actions for this species is assessing the status of remaining populations. The long-term surveys required to adequately document population trends are lacking, as they are generally labor-intensive and time-consuming. We used community and citizen science–collected data and free pattern-recognition software to conduct a mark–recapture study on female Blanding's turtles in a northwest Ohio wetland. Over a 5-yr period, community and citizen scientists gathered 155 images of 65 individual female Blanding's turtles. Our results suggest the wetland has a population of 87 (95% CI = 74–116; SE = 10.1) adult female Blanding's turtles. Deriving preliminary population estimates from photographic recapture data is an example of how the efforts of community and citizen scientists can benefit ongoing research projects and conservation efforts.

Blanding's Turtle Hatchling Survival and Movements following Natural vs. Artificial Incubation

To provide estimates of Blanding's Turtle (Emydoidae blandingii) hatchling survival and to better understand the utility of alternative management tactics targeting this age class, we monitored survival and movements after natural (caged) and artificial incubation by using radio telemetry. We found that survival was similarly high (ca. 80% over 88 days) across treatments and study locations. Movement distances were similar among treatments but differed among study locations, perhaps because of differences in release site habitat variables. Our results suggest that nest cages and artificial incubation are equally effective methods for increasing survival to hatching. Extrapolating from the 88 days of our study, until resumption of activity following hibernation, we found survival estimates of 40%–78%, depending on the survival function used. When coupled with published rates of nest survival (6%–41%) and hatch success (47%–87%), anticipated age 0 survival, from egg deposition to emergence from hibernation, ranged from 1%–28%. Although our analysis fills a knowledge gap in Blanding's Turtle demography, further study is needed to improve the precision of survival estimates.

Blanding's Turtle Demography and Population Viability

Blanding's Turtle Demography and Population Viability

Blanding's Turtle Demography and Population Viability

AbstractIn anticipation of U.S. federal status classification (warranted, warranted but precluded, not warranted), scheduled for 2023, we provide population viability analysis of the Blanding's turtle Emydoidea blandingii, a long-lived, late-maturing, semi-aquatic species of conservation concern throughout its range. We present demographic data from long-term study of a population in northeastern Illinois and use these data as the basis for viability and sensitivity analyses focused on parameter uncertainty and geographic parameter variation. We use population viability analysis to identify population sizes necessary to provide population resiliency to stochastic disturbance events and catastrophes, and demonstrate how alternative definitions of ‘foreseeable future' might affect status decisions. Demographic parameters within our focal population resulted in optimistic population projections (probability of extinction = 0% over 100 y) but results were less optimistic when catastrophes or uncertainty in parameter estimates were incorporated (probability of extinction = 3% and 16%, respectively). Uncertainty in estimates of age-specific mortality had the biggest impact on population viability analysis outcomes but uncertainty in other parameters (age of first reproduction, environmental variation in age-specific mortality, percent of females reproducing, clutch size) also contributed. Blanding's turtle demography varies geographically and incorporating this variation resulted in both mortality- and fecundity-related parameters affecting population viability analysis outcomes. Possibly, compensatory variation among demographic parameters allows for persistence across a wide range of parameter values. We found that extinction risk decreased and retention of genetic diversity increased rapidly with increasing initial population size. In the absence of catastrophes, demographic conservation goals could be met with a smaller initial population size than could genetic conservation goals; ≥20–50 adults were necessary for extinction risk &amp;lt;5%, whereas ≥50–110 adults were necessary to retain &amp;gt;95% of existing genetic diversity over 100 y. These thresholds shifted upward when catastrophes were included; ≥50–200 adults were necessary for extinction risk &amp;lt;5% and ≥110 to &amp;gt;200 adults were necessary to retain &amp;gt;95% of existing genetic diversity over 100 y. Impediments to Blanding's turtle conservation include an incomplete understanding of geographic covariation among demographic parameters, the large amount of effort necessary to estimate and monitor abundance, and uncertainty regarding the impacts of increasingly frequent extreme weather events.

Environmental DNA bioassays corroborate field data for detection of overwintering species at risk Blanding's turtles (Emydoidea blandingii).

Environmental DNA (eDNA) is gaining traction in conservation ecology as a powerful tool for detecting species at risk. We developed a quantitative polymerase chain reaction assay to detect a DNA amplicon fragment of the mitochondrial nicotinamide adenine dinucleotide locus of the Blanding's turtle (Emydoidea blandingii) for detecting overwintering individuals. Seventy-eight water samples were collected from 17 wetland sites in Ontario, Canada. We used traditional field data to identify a priori positive and negative control sites. Fifty percent of positive control sites amplified. Detection was related to the number of individuals estimated from field observations in at least one region surveyed. Positive control sites had lower total dissolved solids and electrical conductivity in relation to negative control sites. Shedding rates were within the same order of magnitude for brumating and active turtles. We recommend collecting additional samples at a larger number of locations to maximize detection. Recommended sampling design changes may overshadow the additional effects of water chemistry and low eDNA shedding rates. eDNA offers tremendous potential to practitioners conducting species at risk assessments in environmental consulting by providing a faster, more efficient method of detection compared with traditional surveys.