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Turtles and tortoises (Order Testudines) are facing an extinction crisis, and ecosystems are at risk of collapsing with the loss of key roles they play. Hatching failure is a crucial barrier to population growth and persistence, but its causes are poorly understood, and it is unknown whether fertilization rates are declining as many populations become smaller and more female‐biased. Here, we show that very few studies of turtle and tortoise hatching success consider fertilization rates, and those that do use unreliable methods to determine egg fertility. We also show that studies of hatching success are biased towards marine turtles, as opposed to freshwater and terrestrial species, and wild rather than captive populations. To address the lack of reliable methods for assessing fertilization rates in turtles and tortoises, a microscopy‐based method (originally designed for bird eggs) for detecting perivitelline membrane (PVM) bound sperm and embryonic nuclei in the germinal disc of unhatched eggs has been developed and tested (in turtle and tortoise eggs). We demonstrate that this method provides unequivocal evidence of egg fertilization in five different turtle and tortoise species from both captive and wild populations, even after eggs have been left in wild nests for the full incubation period. This methodological approach represents a valuable tool for monitoring egg fertility and embryo survival rates in turtles and tortoises, with the potential to provide important insights into the underlying drivers of reproductive failure in threatened captive and wild populations. [ABSTRACT FROM AUTHOR]

Freshwater turtles are often used as terrarium pets, especially juveniles of exotic species. At the adult stage they are often released by their owners into the wild despite their high invasion potential. In Europe these thermophilic potentially invasive alien species occupy the habitats of the native European pond turtle Emys orbicularis (Linnaeus, 1758), with new records from the wild being made specifically in Eastern Europe (Latvia and Ukraine) during recent decades. Assessing the potential of alien freshwater turtles to establish in new territories is of great concern for preventing invasion risks while preserving native biodiversity in the present context of climate change. We explored this issue by identifying the present and future (by 2050) suitable habitats of the European pond turtle and several potentially invasive alien species of freshwater turtle already settled in Europe, using a geographic information system (GIS) modelling approach based on datasets from CliMond for climate, Near-global environmental information (NGEI) for freshwater ecosystems (EarthEnv) and Maxent modelling using open-access databases, data from the literature and original field data. Modelling was performed for seven species of alien freshwater turtles occurring from the extreme northern to southern borders of the European range of E. orbicularis: the pond slider Trachemys scripta (Thunberg and Schoepff, 1792), the river cooter Pseudemys concinna (Le Conte, 1830), the Florida red-bellied cooter Pseudemys nelsoni (Carr, 1938), the false map turtle Graptemys pseudogeographica (Gray, 1831), the Chinese softshell turtle Pelodiscus sinensis (Wiegmann, 1835), the Caspian turtle Mauremys caspica (Gmelin, 1774) and the Balkan terrapin Mauremys rivulata (Valenciennes, 1833). In Ukraine, the most Eastern limit of E. orbicularis distribution, were previously reported northern American originated T. scripta, M. rivulata, M. caspica, whereas in Latvia, Emys' most northern limit, were additionally reported P. concinna, P. nelsoni, G. pseudogeographica and Asia originated P. sinensis. The resulting Species Distribution Models (SDM) were of excellent performance (AUC > 0.8). Of these alien species, the most potentially successful in terms of range expansion throughout Europe were T. scripta (34.3% of potential range expansion), G. pseudogeographica (24.1%), and M. caspica (8.9%) and M. rivulata (4.3%) mainly in Eastern Europe, especially in the south of Ukraine (Odesa, Kherson, Zaporizhzhia regions, and Crimean Peninsula). Correlation between the built SDMs for the native E. orbicularis and the invasive alien T. scripta was reliably high, confirming the highly likely competition between these two species in places they cooccur. Moreover, a Multiple Regression Analysis revealed that by 2050, in most of Europe (from the western countries to Ukraine), the territory overlap between E. orbicularis and potentially invasive alien species of freshwater turtles will increase by 1.2 times, confirming higher competition in the future. Importantly, by 2050, Eastern Europe and Ukraine are predicted to be the areas with most suitable habitats for the European pond turtle yet with most limited overlap with the invasive alien species. We conclude that Eastern Europe and Ukraine are the most relevant priority conservation areas for the European pond turtle where it is now necessary to take protective measures to ensure safe habitat for this native species on the long-term. [ABSTRACT FROM AUTHOR]

Despite suffering dramatic declines due to habitat loss and overexploitation, tortoises and freshwater turtles in Southeast Asia remain understudied. Sustainable forest management offers a promising approach for advancing the conservation of threatened turtle populations. This study examines the effect of reduced impact logging (RIL), a sustainable forestry method, on 2 freshwater turtle species. We examined detectability patterns and habitat relationships for the threatened Malayan flat‐shelled turtle (Notochelys platynota) and the non‐threatened Malayan soft‐shelled turtle (Dogania subplana) in 8 streams within a commercial forest reserve between March and July 2019, in Sabah, Malaysian Borneo. Using single‐species occupancy models, we identified covariates associated with the detection and occupancy probabilities of these species across a post‐harvest recovery gradient (1–21 years since logging). Covariates used in the models were obtained directly from the field or from open‐source remote sensing data. Results for soft‐shelled turtles were inconclusive. In contrast, we found a negative association between monthly rainfall and flat‐shelled turtle detectability. The occupancy probability of flat‐shelled turtles was positively associated with greater distance from logging roads and higher stream flow accumulation. Occupancy probability for flat‐shelled turtles and soft‐shelled turtles was relatively high throughout the reserve (0.79 ± 0.1 [SD] and 0.57 ± 0.22, respectively). These results, suggest that appropriately managed forests, could serve as invaluable conservation areas for imperiled freshwater turtle species in the region. [ABSTRACT FROM AUTHOR]

How often males and females need to mate to maximize their fitness is a source of sexual conflict in animals. Sexual conflict over mating frequency can lead to antagonistic coevolution in which males employ tactics to coerce females into mating, while females resist or evade mating attempts by males. Here, we report on a novel burying behavior observed in female northern map turtles (Graptemys geographica) in Opinicon Lake, Ontario, Canada that appears to function as a tactic to avoid male detection during the mating season. Underwater videos indicated that females are heavily solicited during the mating season with over half the females being actively pursued by males. Biologgers indicated that females are less active and remain deeper than males during the mating season. Our data strongly suggest that female northern map turtles avoid intense solicitation and potential harassment by males by burying themselves in lake sediments. This behavior appears to be a low‐cost solution for females to reduce the costs of resistance and mating while they are constrained to habitats with high male densities for overwintering. [ABSTRACT FROM AUTHOR]

Conservation decisions are often based on population models that rely on underlying assumptions made about species' demographic parameters. The Rio Grande Cooter (Pseudemys gorzugi) is a conservation-dependent riverine turtle, but our understanding of its population dynamics has been limited due to the absence of long-term surveys. We used mark-recapture data collected between 2016 and 2022 from the Black River, New Mexico, USA, to evaluate P. gorzugi somatic growth parameters. Females reached larger maximum size than males but exhibited a slower growth rate. We observed only a slight difference in maximum length and Brody growth coefficient of turtles from different locations, but the growth coefficients were overall significantly lower than any other Pseudemys species. Turtles on the Black River represent the northernmost robust population of P. gorzugi. In light of the intense human use of the river and riparian areas coupled with the impacts of climate change, it is imperative to maintain commitment to conservation efforts to resist population declines given the slow somatic growth rate of the population. [ABSTRACT FROM AUTHOR]

Four wild chelonians (two three-toed box turtles [Terrapene triunguis] and two red-eared sliders [Trachemys scripta elegans]) were presented to an academic wildlife rehabilitation center after presumably being hit by a car. Physical examinations revealed various carapace, bridge, and plastron fractures, as well as a lack of motor function of different limbs. A craniodorsal-caudoventral oblique view or caudodorsal-cranioventral oblique radiographic view made at 45° to the frontal plane (Cr45D-CdV and Cd45D-CrV oblique views, respectively), along with standard views (i.e., dorsoventral, right lateral, craniocaudal views), were performed. The oblique views allowed for visualization of different pectoral girdle or pelvic girdle fractures that were not visualized or clearly identified on the standard views. Based on the four clinical cases described here, the addition of Cr45D-CdV or Cd45D-CrV oblique views to the standard views may be beneficial, especially when advance imaging such as computed tomography is not available. These oblique views can be used to better assess chelonian pectoral and pelvic girdles because these structures are superimposed in standard radiographs. Future studies investigating the diagnostic accuracy of detecting pelvic and pectoral girdle fractures using these views are warranted. [ABSTRACT FROM AUTHOR]

N-acetyl-beta-d-glucosaminidase (NAG) is a lysosomal enzyme found in renal tubular epithelial cells, the concentration of which can be measured in blood as a possible diagnostic tool to monitor renal disease; however, no reference values are currently available in reptiles. This study investigated the presence of plasma NAG concentrations in three reptile species. Blood samples were obtained from clinically healthy bearded dragons (Pogona vitticeps; n = 13), corn snakes (Pantherophis guttatus; n = 9) and wood turtles (Glyptemys insculpta; n = 13). To assess renal health further, a biochemistry panel was performed for all animals, and renal biopsies were collected from the bearded dragons and snakes, but not from the turtles. Biopsies were not taken from wood turtles to limit the risk associated with anesthetizing an endangered species. Of the 35 animals sampled, 29 were considered healthy and included in the study. Plasma NAG concentrations in the wood turtles were significantly lower than in the corn snakes (P = 0.004) and plasma NAG concentrations in the corn snakes were significantly higher than in bearded dragons (P = 0.038). Wood turtles had the lowest NAG concentrations, followed by bearded dragons and corn snakes. In conclusion, NAG reference intervals should be established for each reptile species, and analyte validation is needed for this assay in reptiles. Further research is needed to establish NAG reliability as a diagnostic tool in reptiles. [ABSTRACT FROM AUTHOR]

Turtle species in the Family Podocnemididae, including the Colombian endemic and critically endangered Magdalena River Turtle Podocnemis lewyana, characteristically present low recapture rates that preclude estimation of population parameters using maximum likelihood modeling. In our 12-year monitoring project with this species, we evaluated changes in relative abundances, proportions of sex/size classes, and individual body sizes and body conditions in a population in four channels in the middle Magdalena River drainage. We also inspected for associations between trends in changes in these variables and differences in hunting pressure and habitat degradation. To inspect for temporal and spatial demographic dynamics, we estimated variation in relative abundances using the Catch Per Unit Effort index, the total number of turtles captured over an entire 5-day sampling period using ten baited funnel traps. Relative abundances and the proportions of sex/size classes were different between sites and years. We found a significant decline in the proportion of females and juveniles over time, along with evidence that the females still present were smaller in body size. Our results support the hypothesis that hunting eliminates adult females from these sites, perhaps also translating into a reduction in recruitment. The lack of evidence of generalized declines in body condition of all size classes suggests that habitat degradation might contribute less to the population declines in this region. Our results also illustrate that even when recapture rates are low, monitoring turtles via standardized trapping may yield insights into the population's conservation status that other relative abundance indices cannot. [ABSTRACT FROM AUTHOR]

Coastal habitats are some of the most imperiled due to climate change and anthropogenic activities. As such, it is important to understand population dynamics of the species that may play a role in regulating coastal systems. Diamondback terrapins in Northwest Florida have been understudied, which has resulted in a gap in our knowledge for this region. To help fill this gap, we conducted a capture-mark-recapture study in St. Joseph Bay, Florida, from 2018 to 2021. Overall, we captured 518 individuals, including 146 recaptures, and we used several modeling frameworks to estimate apparent survival, recapture probability, population entrance, and population size. Our estimates of apparent survival were relatively low, especially for adult males (0.77) and adult females (0.83), but there is a considerable amount of uncertainty around our estimates. Our models indicated that the super-population consists of 1122 individuals (971–1327 95% CI), and the population is comprised of more adult males (753; 665–866 95% CI) than adult females (102; 85–130 95% CI) and juveniles (267; 221–331 95% CI). Estimates of population entrance varied by year throughout our study duration. This study is the first to document a Malaclemys terrapin population in this region of Florida, and we recommend long-term monitoring in order to gain inferences for the management of this declining coastal species. [ABSTRACT FROM AUTHOR]

Fences disturb the movements of terrestrial species, altering migration patterns, limiting access to vital resources, and reducing genetic diversity. With almost 40% of the Earth's land surface converted for agriculture, farm fencing to protect crops and corral livestock is expected to stretch into the millions of kilometers. As semi‐terrestrial ectotherms, freshwater turtles are threatened by fences that limit access to resources and increase risks of desiccation, entanglement, and overheating, often resulting in death. To determine the effect of fences, we quantified the movement patterns for a population of eastern long‐necked turtles (Chelodina longicollis) inhabiting an agricultural landscape near Armidale, New South Wales, Australia from November 2022 to September 2023. There was considerable variation in the distance traveled, home range size, and movement corridor selection between turtles that was not explained by the morphological factors of size, mass, or the loss of a limb (likely due to predation attempts). On average, 38% ± 4.70 ( x ¯ $\bar{x}$ ± SE) of turtle movements were terrestrial (overland) during their active season (spring and summer) during which they encountered fences frequently because of a complex matrix of paddocks. Fence design dictated the distance turtles traveled to locate a suitable passage point. The majority of fences allowed turtles to pass (turtle‐friendly fences, 71.4% of total fence distance) as opposed to turtle‐unfriendly fences (28.6% of total fence distance). Turtles were required to travel almost 4 times the distance to locate a suitable crossing point (a gap or fault in the fence) when they encountered an unfriendly fence (85.32 m ± 29.81) compared to a turtle‐friendly fence (25.85 m ± 3.58). Our results highlight the need for land managers to avoid small‐diameter exclusion fencing and fence designs containing chicken wire that extend to or below ground level. In settings where small‐diameter wire fencing is required, we recommend the installation of turtle gates for small terrestrial fauna or elevating bottom wires at least 50 mm above ground level to facilitate fence permeability. [ABSTRACT FROM AUTHOR]

The current study examines the growth pattern and lifestyle habits of the freshwater snapping turtles Chelydra and Macrochelys based on limb bone histology. Femora, humeri, and tibiae of 25 individuals selected from a range of ontogenetic stages were assessed to determine inter‐element and intraskeletal histological variation. Osteohistological assessment of multiple elements is consistent with overall moderate growth rates as revealed by the dominance of parallel‐fibered bone. However, the growth was cyclical as shown by deposition of multiple lines of arrested growths in the compacta. It appears that the bone tissue of C. serpentina is more variable through ontogeny with intermittent higher growth rates. M. temminckii appears to grow more slowly than C. serpentina possessing compact and thick cortices in accordance with their larger size. Overall, vascularization decreases through ontogeny with humeri and femora being well‐vascularized in both species. Contrarily, epipodials are poorly vascularized, though simple longitudinal and radial canals are present, suggesting differences in growth patterns when compared with associated diaphyseal sections. The tibiae were found to be the least remodeled of the limb bones and therefore better suited for skeletochronology for snapping turtles. Intra‐elementally, femora and humeri preserved higher cortical vascularity ventrally, suggestive of faster relative growth. We hypothesize that the differential growth pattern in limb bones of snapping turtles may relate to differential functional constraints, where forelimbs are operational in swimming while the hindlimbs provide stability. [ABSTRACT FROM AUTHOR]

Invasive species are one of the leading causes of biodiversity loss. During demographic monitoring of native turtle species in northeast Spain, we captured several alien species of semi-aquatic turtles, including Mauremys mutica. Among them, four individuals of this latter species showed external characteristics that were not fully consistent with the diagnosis of this species. These individuals showed a smaller postocular stripe and 2-3 lateral cervical lines and the typical plastral pattern observed in Mauremys leprosa. The analysis of mitochondrial DNA indicated that the maternal lineage was unequivocally M. mutica (pure or hybrid), but nuclear DNA revealed a heterozygote position at the C-mos gene, matching sequences for this gene in GenBank from both M. leprosa and M. mutica. These results highlight the negative impact of alien turtles, which can genetically contaminate vulnerable native turtle populations. [ABSTRACT FROM AUTHOR]

Background: The popularity of tortoises kept in captivity is increasing and has caused concern regarding the necessity to establish safe and straightforward anaesthesia for those reptiles. Aim: This study aimed to compare four protocols using levobupivacaine in spinal anaesthesia for the blockade of the caudal neuraxis of red-footed tortoises (Chelonoidis carbonarius). Methods: Twenty-four tortoises were randomly assigned into four groups: G1, levobupivacaine 0.75% (1.15 mg kg−1); G2, levobupivacaine 0.37% (1.15 mg kg−1); G3, levobupivacaine 0.75% (2.3 mg kg−1); and G4, levobupivacaine 0.75% (0.1 ml 5 cm−1 of straight carapace length). Tortoises were evaluated for respiratory rate, muscle relaxation, response to hindlimb or tail pinch, and cloacal reflex. Results: A 1.15 mg kg−1 dose of levobupivacaine 0.37% appears adequate for shorter procedures, whereas a 1.15 mg kg−1 dose of levobupivacaine 0.75% should be appropriate for longer procedures in red-footed tortoises. Conclusion: Our results are the first to show the effects of levobupivacaine on spinal anaesthesia in reptiles. Weight-based doses presented more intense and more homogeneous effects than carapace length-based doses in red-footed tortoises. Spinal anaesthesia of red-footed tortoises was safe and effective with any of the weight-based protocols. [ABSTRACT FROM AUTHOR]

Studying the interactions between prey and predators is crucial for understanding the intricacies of predator-prey dynamics and for formulating effective conservation strategies. Yet there is almost no systematic analysis of pancake tortoise predation, and its consequences on the tortoise populations. Using camera trapping and visual encounter surveys, we recorded the animals visiting the crevices inhabited by pancake tortoises, as well as their surroundings. From our data, we propose which visitors were potential predators, and consider predator impacts on the species. We suggest ten species (21.3%) as potential predators, among the 47 visiting the tortoise crevices between July 2020 and November 2022. We encountered six adult pancake tortoises killed and eaten by unknown predators. Four of six eggs laid by pancake tortoises in May−June 2022 were also depredated. The white-tailed mongoose (Ichneumia albicauda) and the honey badger (Mellivora capensis) were recorded probing rock crevices inhabited by pancake tortoises, with their behaviour suggesting potential predation upon tortoises. We recorded the rock monitor lizard (Varanus albigularis) and common dwarf mongoose (Helogale parvula) digging pancake tortoise nest sites. This study significantly advances our understanding of the predation risk to the critically endangered pancake tortoise. [ABSTRACT FROM AUTHOR]

Simple Summary: Animal personalities could affect the behavior and physiology of both native and invasive species during biological invasion. However, little is known about the personality interaction effects on foraging behavior and growth between native and invasive species. We used the red-eared slider turtle and Chinese pond turtle as models to investigate how personality interactions effect the foraging behavior and growth of both these turtle species. The results showed that the foraging behavior of M. reevesii was mainly affected by the personality of T. scripta elegans. However, the foraging behavior of T. scripta elegans was effected by both their own personality and the personalities of M. reevesii. Additionally, the growth of both M. reevesii and T. scripta elegans were not effected by the personality combinations. The results revealed the mechanisms of personality interaction effects on the foraging behavior and growth of both native and invasive species during biological invasion. This study provides empirical evidence to help understand the effects of personalities on invasion dynamics. Animal personalities play a crucial role in invasion dynamics. During the invasion process, the behavioral strategies of native species vary among personalities, just as the invasive species exhibit variations in behavior strategies across personalities. However, the impact of personality interactions between native species and invasive species on behavior and growth are rarely illustrated. The red-eared slider turtle (Trachemys scripta elegans) is one of the worst invasive species in the world, threatening the ecology and fitness of many freshwater turtles globally. The Chinese pond turtle (Mauremys reevesii) is one of the freshwater turtles most threatened by T. scripta elegans in China. In this study, we used T. scripta elegans and M. reevesii to investigate how the personality combinations of native and invasive turtles would impact the foraging strategy and growth of both species during the invasion process. We found that M. reevesii exhibited bolder and more exploratory personalities than T. scripta elegans. The foraging strategy of M. reevesii was mainly affected by the personality of T. scripta elegans, while the foraging strategy of T. scripta elegans was influenced by both their own personality and personalities of M. reevesii. Additionally, we did not find that the personality combination would affect the growth of either T. scripta elegans or M. reevesii. Differences in foraging strategy may be due to the dominance of invasive species and variations in the superficial exploration and thorough exploitation foraging strategies related to personalities. The lack of difference in growth may be due to the energy allocation trade-offs between personalities or be masked by the slow growth rate of turtles. Overall, our results reveal the mechanisms of personality interaction effects on the short-term foraging strategies of both native and invasive species during the invasion process. They provide empirical evidence to understand the effects of personality on invasion dynamics, which is beneficial for enhancing comprehension understanding of the personality effects on ecological interactions and invasion biology. [ABSTRACT FROM AUTHOR]

Macrochelys temminckii (alligator snapping turtle) is an aquatic turtle endemic to the southeastern United States that was proposed for listing under the Endangered Species Act in 2021. In the present study we analyzed total mercury (THg) concentrations in skeletal muscle, tail clips, and nail tissue of 93 M. temminckii sampled from 14 waterbodies in eastern Texas (USA). Our objectives were to assess (1) the degree of correlation between internal tissue (skeletal muscle and tail clip samples) and keratin (nail samples), (2) the influence of ecological factors (turtle size and waterbody/sampling site) on THg concentrations, and (3) whether THg concentrations were high enough to pose a risk to human consumers. The mean (±SE) THg concentrations of muscle and nail were 1.16 ± 0.08 μg/g dry weight and 4.21 ± 0.24 μg/g dry weight, respectively, and THg concentrations were highly dependent on the sampling site. The THg concentrations of nails were correlated with muscle concentrations (R2 = 0.56, p < 0.001). The effect of body size on THg concentrations varied by sampling site, indicating that size is not a good predictor of Hg concentration across sites. Finally, THg concentrations in M. temminckii of eastern Texas were high enough to pose a potential risk to human health based on US Environmental Protection Agency dietary guidelines. Environ Toxicol Chem 2024;43:1903–1913. © 2024 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

The presence of domestic animals in the wilderness has a negative effect on wildlife populationsor; for instance, in addition to habitat loss, urbanization, and coastal light pollution, sea turtles also suffer from another threat: the predation of their eggs, hatchlings, and even female nesters by domestic, feral, and/or wild animals. Domestic dogs are a considerable concern for turtles in nesting areas, due to their free-ranging lifestyle and the absence of predators. This study sought to evaluate the nest density and rates of sea turtle predation caused mainly by canids: foxes (native predator) and dogs (introduced predator) in the nesting areas of Southern Bahia, Brazil. Predation data was collected during field surveys and by using camera traps and hair traps installed in nests. During the sampling period, an average of 46 nests were laid by three sea turtle species: Caretta caretta, Eretmochelys imbricata, and Lepidochelys olivacea; 46.4% were lost due to predation or inundation caused by the tides. Canine populations on the island have an evident impact on sea turtle nests. Thus, it is crucial to design and implement environmental education programs and management plans with the local community to help reduce human-made and natural loss of nests and safeguard sea turtle populations and their habitat. [ABSTRACT FROM AUTHOR]

Freshwater turtles exhibit temporary threshold shifts (TTS) when exposed to broadband sound, but whether frequency-restricted narrowband noise induces TTS was unknown. Underwater TTS was investigated in two freshwater turtle species (Emydidae) following exposures to 1 6 -octave narrowband noise (155–172 dB re 1 μPa2 s). While shifts occurred in all turtles at the noise center frequency (400 Hz), there were more instances of TTS and greater shift magnitudes at 1 2 octave above the center frequency, despite considerably lower received levels. These frequency-specific data provide new insight into how TTS manifests in turtles and expand empirical models to predict freshwater turtle TTS. [ABSTRACT FROM AUTHOR]

Interaction with fishing gears represents the main anthropogenic threat at sea for sea turtles worldwide, and identifying the hotspots of turtle bycatch is a priority knowledge gap.Turtle stranding data represent a source of information about mortality areas at sea that are not fully exploited. This study aims to infer turtle mortality areas of turtles stranded along the Italian Adriatic Coast in the period 2019–2021 (1432 records), through backtrack modelling of carcasses. Specifically, the decomposition process of eight loggerhead carcasses was monitored, and the relationship between floating period (FP), turtle size and sea temperature was modelled through a generalized additive model. Oceanographic information was then used to track the routes of floating carcasses back, knowing their size and decomposition stage, and finally estimate the likely area of mortality. A complementary numerical experiment of connectivity between coastal and offshore areas gave indication that areas of potential mortality are relatively close to the coast, particularly in the northern Adriatic.Stranded turtles probably represent just a small fraction (17%–25%) of total at‐sea mortalities in the study area (Italian Adriatic waters), with decomposition rates, season and distance from shore influencing their stranding likelihood. Hence, strandings can inform only about spatio‐temporal variability of coastal mortality hotspots.Inferred areas of turtle mortality were most likely located in the North and Central Adriatic all over the year and overlap with heatmaps of fishing effort, obtained from vessel monitoring system (VMS) and automatic identification system (AIS) data, in the Gulf of Manfredonia and in the North‐West Adriatic in the cold (September–December) and warm (May–August) periods, respectively. [ABSTRACT FROM AUTHOR]

Fibropapillomatosis (FP) is a debilitating tumoral disease affecting sea turtles worldwide. While mainly afflicting immature individuals and potentially altering vital functions, the precise impact of this panzootic on turtle health and survival remains unclear. Moreover, the etiological factors implicated in the FP emergence, development and transmission are not yet definitively identified. Among them, an infection by a spreading herpesvirus and the contamination by pollutants (either organic pollutants and trace elements) are suspected. Here, we provide an overview of discoveries, knowledge and propose hypotheses related to FP within five key FP research areas, i.e., virology studies, transmission studies, contamination studies, host genomic studies, and veterinary treatment assays. Moreover, we recommend urgent research avenues to develop at the interface of virology, epidemiology, ecotoxicology, oncology, physiology, immunology, cellular and evolutionary biology, in order to characterize the dynamics of FP and to predict its consequences on sea turtle populations. Importantly, extending the implementation and development of strong collaborations between rehabilitation centers, field biologists and research laboratories at large geographical scale is required to rapidly increase our knowledge on FP and work towards its effective management. [ABSTRACT FROM AUTHOR]

Genetic characteristics of North Pacific loggerhead turtles captured as bycatch in pound nets operating inMuroto, Kochi, Japan were sampled to identify and estimate stock structure of coastal foraging aggregations. Tissue samples were obtained from juvenile, subadult and adult turtles from 2005-2006 and 2008-2010. For each of the years, 100 samples were processed and approximately 820 bp of mitochondrial DNA control region were sequenced. Straight carapace length of the turtles ranged from 56.3-99.1 cmand their life stages were identified based on previous estimates of the size at puberty (66.0cm) and maturity (82.1cm). A total of 487 out of the 500 samples yielded sequences of sufficient quality to identify five different haplotypes. We conducted mixed stock analysis (MSA) using Bayesian approaches to estimate the contributions of three potential source nesting Management Units (MU) to the Muroto foraging aggregation. There were no significant differences between haplotype frequencies among the different size classes and life stages, nor among the different years, thus the haplotype frequencies were combined for the MSA. The MSA was runwith and without consideration of MUsize and distance, which resulted in similar MSA estimates. A >50% contribution was estimated from the Yakushima MU, and 40% from the Mainland MU, with only minor contribution from the Ryukyu MU. The estimated contribution from Mainland MU and Yakushima MU were disproportionately larger than the relative abundance of nesting at these MUs compared with Ryukyu MU, demonstrating that closer MUs had a greater contribution than those from further away. The lack of differences found in haplotype frequency among life stages, suggests that both juvenile and mature loggerhead turtles that remigrate to Japanese waters have the tendency to utilize foraging grounds and migration routes near their natal waters. [ABSTRACT FROM AUTHOR]

The present investigation examined the oropharyngeal roof of two turtles having different feeding behaviors: the landform Greek tortoise (Testudo graeca graeca) primarily herbivores and the semi-aquatic red-eared slider turtle (Trachemys scripta elegans) lives in freshwater that opportunistic omnivorous grossly and by scanning and light microscopes. Grossly, the Greek tortoise had a V-shaped roof consisting of the upper rhamphotheca, peri-palatine region, upper alveolar ridge, peripheral palatine ridge, median palatine ridge, vomer, choanae, caudal palatine part, and pharynx. At the same time, the red-eared slider had a semilunar roof consisting of upper rhamphotheca, two peripheral palatine ridges, core of palatine ridges, upper alveolar band, vomer, choanae, caudal palatine part, and pharynx. SEM revealed that the red-eared slider roof appeared more straightforward. The upper rhamphotheca is sharp, with a median premaxillary notch in the red-eared slider that gives a powerful bite for cutting to compensate absence of the teeth. Additionally, the red-eared slider's upper alveolar band is interrupted by a single upper alveolar ridge that appears spiky, pointed, and longer as it needs powerful chewing of prey and there are two types of teeth-like projections at its peri-palatine area for food-crushing and chewing. The Greek tortoise palatine region had numerous ridges and folds to provide roughness for food processing. Greek tortoises had small-sized choanae with two choanal folds to minimize choanal openings when eating dusty grasses. Histologically, Greek tortoise palate was rostrally thicker and more keratinized than caudally, and the caudal palatine region was characterized by a single pair of circumvallate-like papilla with multiple mucous openings and secretions, while red-eared slider palate was slightly keratinized at the peri-choanal region, and the rest of the palate was non-keratinized with few mucous openings. The current investigation found various structural oropharyngeal roof adaptations to feeding behavior in the omnivore red-eared slide compared to the herbivorous Greek turtle. [ABSTRACT FROM AUTHOR]

Social interactions are inevitable in the lives of most animals, since most essential behaviours require interaction with conspecifics, such as mating and competing for resources. Non-avian reptiles are typically viewed as solitary animals that predominantly use their vision and olfaction to communicate with conspecifics. Nevertheless, in recent years, evidence is mounting that some reptiles can produce sounds and have the potential for acoustic communication. Reptiles that can produce sound have an additional communicative channel (in addition to visual/olfactory channels), which could suggest they have a higher communicative complexity, the evolution of which is assumed to be driven by the need of social interactions. Thus, acoustic reptiles may provide an opportunity to unveil the true social complexity of reptiles that are usually thought of as solitary. This review aims to reveal the hidden social interactions behind the use of sounds in non-avian reptiles. Our review suggests that the potential of vocal and acoustic communication and the complexity of social interactions may be underestimated in non-avian reptiles, and that acoustic reptiles may provide a great opportunity to uncover the coevolution between sociality and communication in non-avian reptiles. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'. [ABSTRACT FROM AUTHOR]

Frozen water bodies provide a physiological challenge to fauna by physically limiting access to atmospheric oxygen. To tolerate low temperatures, reptiles use brumation as a physiological strategy in winter. Cryptodira vary in their tolerance to freezing conditions but the extent of tolerance in pleurodirans is largely unknown. Australia's freshwater turtles inhabit warmer regions with less severe winters and have well‐developed mechanisms to cope with high temperatures and drying waterbodies, rather than extreme cold tolerance. Chelodina longicollis is a widespread Australian freshwater turtle species that tolerates high temperatures and desiccation during hot, dry periods while also undergoing brumation during winter months. Despite extensive research, limited observations exist on their behaviour during severe winter periods at the extremes of their range. In an 11‐month tracking study, we monitored adult C. longicollis, noting their movements, locations, and temperature weekly. We observed an adult female C. longicollis which, during a seven‐month period within a single creek pool, survived brumation in extreme cold water including a 15‐day period of total freezing of the surface water. After the ice melted following a rain event, the turtle was recaptured alive. This marks the first observation of brumation for an Australian chelid species under ice. [ABSTRACT FROM AUTHOR]

This study provides empirical data on the balancing, production, and quality of freshwater turtle diets containing partially defatted black soldier fly larvae Hermetia illucens meal (BSFL) as a fish meal (FM) replacement. A 70-day experiment was performed using 27 Jardine river turtle (Emydura subglobosa) juveniles (6 months old). Three dietary treatments were applied, namely, CON with 30% fish meal and no BSFL as the control, H75 with 22.5% fish meal and 7.5% BSFL, and H150 with 15% fish meal and 15% BSFL, with 3 replicates per treatment, 3 animals per replicate, and 9 specimens in total per treatment. Post-extrusion tests showed that feed technological parameters are dependent on the BSFL meal proportion in terms of the pellet length expansion rate, volume increase, and water binding capacity. The obtained experimental feeds were well accepted by the animals. During the entire experimental period, no turtle mortality, diet-related issues, or differences in shell development or growth performance were recorded among the treatments. However, the feed intake increased in comparison to CON when 7.5% BSFL meal was used (42.30 g vs. 50.40 g), and a lower feed conversion ratio was observed in the 15% BSFL treatment (1.51 vs. 1.38). For the first time, it was empirically proven that E. subglobosa can efficiently utilize BSFL meal for up to 15% of their diet. Moreover, the possibility of an increase in environmental sustainability during turtle husbandry due to a decrease in total marine resource use of 55.8% and a 57.4% decrease in the use of fish meal per kg of body weight gain were recorded. [ABSTRACT FROM AUTHOR]

Daily activity patterns of free‐ranging wildlife affect a wide range of ecological and physiological processes and, in turn are affected by anthropogenic disturbances to the environment. However, obtaining a continuous record of activity without disturbing wild animals is logistically challenging. We used commercially available, multi‐purpose light‐level geolocator dataloggers to continuously record light environment and time spent out of water during 5‐months (1 May to 9 September 2021) in an ectothermic freshwater turtle species, the northern map turtle (Graptemys geographica). We used these data to compare time of year and sex differences in thermoregulatory behavior in an ectothermic species in its natural habitat. We recorded >500 000 data points from 17 individual turtles (nine males and eight females). We found no differences in the mean light levels, or proportion of time spent out of the water, between males and females. However, there was a significant effect of both time of year and sex by time of year interaction in both light level, proportion of time spent dry, and number of state changes (i.e., shuttling behavior, wet to dry or dry to wet), suggesting that turtles alter their aerial basking behavior over the course of the season and that the changes in patterns of aerial basking behavior differ between the sexes throughout the year. In general, the proportion of time spent dry decreased over the active season, with an increase during the last week of June and the first week of July, while the number of state changes increased in females during late May/early June before decreasing, while males remained relatively constant. These changes may reflect the different energetic demands associated with reproduction between the two sexes. The overall downward trend in aerial basking likely reflects the role of increasing environmental temperatures, particularly water temperature, in the maintenance of body temperature in this largely aquatic species. [ABSTRACT FROM AUTHOR]

Urbanization is a significant driver of the global biodiversity crisis. Turtles are particularly impacted by urbanization because of the vulnerability of riparian habitats to habitat loss and road mortality. Behaviour plays a crucial role in determining the success of urban animals. Behavioural responses to urbanization, however, are rarely studied in turtles even though many turtles are at‐risk and sometimes live in urban areas. Therefore, we evaluated behavioural changes in painted turtles (Chrysemys picta) living in wetlands surrounded by a gradient of urbanization. We tested the consistency of painted turtle behaviour in the laboratory and examined the behaviour of painted turtles from 24 wetland sites across an urbanization gradient in Ottawa, Ontario, Canada. We assessed: (i) aggression by measuring the number of active defensive behaviours the turtles performed in response to handling, (ii) boldness by measuring the amount of time the turtles took to emerge from their shells and move from their initial locations in a circular arena and (iii) activity by measuring the amount of time the turtles spent moving in the same circular arena. We found that all behaviours were consistent in the laboratory. We also found that as the level of urbanization increased, turtles were more aggressive and bolder. Urbanization affects painted turtle behaviour, but further research is required to understand the mechanisms responsible and the conservation implications. [ABSTRACT FROM AUTHOR]

Reptiles are threatened by anthropogenic landscape transformation, largely due to agriculture. However, ecosystems nowadays constitute a matrix of fragmented landscapes. We analyzed a heterogeneous landscape's reptile taxonomic and functional diversity patterns across ten land cover/use types in Jalisco state, in west-central Mexico. At the alpha diversity level, we assessed the taxonomic diversity using q-order indices, and functional diversity with multidimensional indices (FRic, FDiv, and FEve) by land cover/use. We evaluated the differences in species composition among land cover/use types (beta diversity). We utilized multidimensional distance-based analyses (dbRDA) to evaluate the association between reptile diversity, habitat structure, and environmental variables. Species richness did not correlate with functional richness across land cover types overall, except for riparian habitat surrounded by crops (RH-C), which exhibited higher species richness and functional diversity. Secondary vegetation surrounded by temperate forest (SV-TF), riparian habitat surrounded by tropical dry forest (RH-TDF), and RH-C were the land cover/use types with the most functional groups. Herbaceous cover is crucial for preserving both reptile diversity facets in this landscape. These findings suggest that the availability of resources (e.g., riparian habitat and herbaceous cover) regardless of perturbation level could be more relevant for reptile diversity than the condition (tropical vs. temperate) due to the high plasticity and adaptation of the group. It is essential to recognize the ecological value of these habitats by adopting a holistic approach that values the intrinsic and ecological importance of reptile diversity. [ABSTRACT FROM AUTHOR]

The article provides information on a study which analyzed Lissemys punctata, also known as the India flapshell turtle, basic health in comparison of two diverse areas of water bodies. Topics discussed include biochemical and hematological parameters analysis, key characteristics features studied to identify Lissemys punctata, and biohemical parameters of turtles in Narayanavanam and Somala.

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Due to their natural history and ecological attributes, turtles are excellent organisms for studies of heavy metal contamination. Turtles have a large geographical distribution, occupy different aquatic habitats, and occupy various trophic levels. The present study investigated mercury bioaccumulation in the carnivorous chelonian Chelus fimbriata (Matamata turtle) and Hg biomagnification in relation to its aquatic food chain in the middle Rio Negro, AM-Brazil. Tissue samples of muscle, carapace and claws were collected from 26 C. fimbriata individuals, as well as collections of autotrophic energy sources found in the turtle's aquatic habitat area. The samples were collected in February-March/2014 and analyzed for THg concentrations and carbon (δ13C) and nitrogen (δ15N) stable isotopes. The highest THg levels were found in claws (3780 ng.g−1), carapace (3622 ng.g−1) and muscle (403 ng.g−1), which were found to be significantly different [F(2.73) = 49.02 p < 0.01]. However, THg concentrations in muscle tissue were below the consumption threshold indicated by the WHO and Brazilian Health Ministry. The average δ13C and δ15N values in Matamata samples were −31.7‰ and 11.9‰, respectively. The principal energy source sustaining the food chain of C. fimbriata was found to be terrestrial shrubs, with smaller contributions from emergent aquatic herbaceous plants and algae, while δ15N values showed its trophic position to be two levels above the autotrophic energy sources. There was a positive correlation between THg and turtle size, while a significant relationship was found between THg and δ15N, showing strong biomagnification in the food chain of C. fimbriata: y = 0.21x + 0.46; r2 = 0.45; p < 0.001, for which the slope presented a value of 0.21. [ABSTRACT FROM AUTHOR]

Two nanhsiungchelyid carapaces from the Upper Cretaceous of Ganzhou Basin, Jiangxi Province, Southern China, are reported and assigned to Nanhsiungchelys sp. The new material reveals an unusual carapace morphology that was either not or poorly preserved in previously known Nanhsiungchelys specimens, including differentiated neurals, alternating costals, significantly modified scutes with vertebrals 4–5 contacting each other at a point, reduced pleurals 2–4 and greatly expanded lateral and posterior marginals. The discovery extends the geographical distribution of Nanhsiungchelys to the Ganzhou Basin. [ABSTRACT FROM AUTHOR]

Illegal poaching and overexploitation for the international pet trade are among the greatest threats to freshwater turtles in Southeast Asia. Expanding consumer research in China is crucial to filling knowledge gaps about the scale and structure of illegal trade and developing audience‐targeted and relevant interventions that may reduce demand for illegal turtles as pets. We applied mixed methods to provide a detailed understanding of the consumer side of the illegal pet turtle trade in China. We conducted 30 interviews with key stakeholders and online surveys (n = 2456) of turtle keepers via community forums. From these, we identified 3 core consumer groups based on their prior turtle‐keeping experience, species exposure, and potential for future purchases. We conducted a thematic qualitative analysis of concepts related to the capability, opportunity, motivation, and behavior (COM‐B) model to determine the factors influencing the illegal pet turtle trade and to identify barriers to illegal purchases. Specifically, we identified purchasers' capabilities, opportunities, and motivations in the context of legality, enforcement risk, captive breeding, and impacts on wild population. We developed consumer journey maps (i.e., visual representations of customer's experiences throughout their buying journey) for core consumer groups. These maps illustrate the sequential behaviors and processes that consumers undertake when purchasing turtles, from initial exposure to sourcing, keeping, and providing a new home. Key factors influencing illegal purchases included convenient purchase channels, misguided cognition and motivations for pet keeping, and weak law enforcement. Effective interventions included messages focusing on shifting cognition and beliefs, increasing legal risk perception, and emphasizing stringent law enforcement, primarily delivered through online channels. Our results underscore the necessity for adaptable, audience‐tailored interventions to reduce consumer demand for illegal wildlife products. The mixed‐methods approach, combining quantitative and qualitative data, provided a comprehensive understanding of the target behavior and can inform the development of effective intervention strategies. [ABSTRACT FROM AUTHOR]

Background: The developmental biology of Kinosternon scorpioides is described, based on the phenotype. This species is important for the flora because they are excellent seed disseminators. In addition, basic embryological information is not yet fully clarified, and this research provides unprecedented information on the chelonian embryology of the Amazonian fauna. Aim: The present study aims to identify the embryology of K. scorpioides in captivity during different periods. Methods: Females were monitored throughout the reproductive cycle, by video monitoring, to identify nests and the presence of newly laid eggs. At regular weekly intervals, embryo samples were collected fixed in a 4% paraformol solution and preserved in 70% alcohol. For the embryonic characterization we used a stereomicroscope and the scanning electron microscopy method. Results: We describe 15 embryonic stages for a 15-week (105-day) incubation process. Only at 42 days (6th week) was the morphological characterization of a chelonian observed and at the 12th week (Stage XII) the phenotypic characterization of the species K. scorpioides. Conclusion: In view of the evidence, we found that these phases are similar to the other turtles, with structural variations in the appearance and disappearance of structures due to the specific characteristics for the species. [Open Vet J 2024; 14(4.000): 962-972]

This paper presents the observations of predation by the grouper Epinephelus quoyanus on sea turtle hatchlings in Chagar Hutang bay, Redang Island, Malaysia. Two of the eight collected specimens had hatchlings in their guts, whereas the remaining specimens had empty stomachs. This field report provides an in‐depth understanding of the E. quoyanus diet and new insights into its feeding behavior. [ABSTRACT FROM AUTHOR]

This research investigated the effect of cadmium on the tissue and cell of kidney of the turtle Mauremys reevesii. Twenty turtles were injected with cadmium at 0, 7.5, 15, 30 mg/kg separately and five turtles were taken in each group at two weeks after exposure. Kidneys were immediately excised and macroscopic pathological changes were observed, then the kidneys were fixed in 4% paraformaldehyde for histopathological examination and fixed in 2.5% (v/v) glutaraldehyde for examination of ultra-structure. The tissues of kidney presented varying degrees of histopathological lesions in cadmium treated turtles by a dose-dependent manner under the light microscope. Under transmission electron microscope, renal tubules cells presented varying degrees of dose-dependent lesions. The results indicated that cadmium can cause cell damages to the kidney, in particular to the mitochondria. Mitochondria can be used as one biomarker in the monitoring of cadmium pollution and its quantitative risk assessments. [ABSTRACT FROM AUTHOR]

We live in a time of accelerated biological extinctions that has the potential to mirror past mass extinction events. However, the rarity of mass extinctions and the restructuring of diversity they cause complicate direct comparisons between the current extinction crisis and earlier events. Among animals, turtles (Testudinata) are one of few groups that have both a rich fossil record and sufficiently stable ecological and functional roles to enable meaningful comparisons between the end-Cretaceous mass extinction (∼66 Ma) and the ongoing wave of extinctions. Here we analyze the fossil record of the entire turtle clade and identify two peaks in extinction rates over their evolutionary history. The first coincides with the Cretaceous-Paleogene transition, reflecting patterns previously reported for other taxa. The second major extinction event started in the Pliocene and continues until now. This peak is detectable only for terrestrial turtles and started much earlier in Africa and Eurasia than elsewhere. On the basis of the timing, geography, and functional group of this extinction event, we postulate a link to co-occurring hominins rather than climate change as the cause. These results lend further support to the view that negative biodiversity impacts were already incurred by our ancestors and related lineages and demonstrate the severity of this continued impact through human activities. [ABSTRACT FROM AUTHOR]

The Asian leaf turtle (Cyclemys dentata) is a freshwater turtle species found in select Southeast Asian countries, including the Philippines. Our understanding of C. dentata's ecology in the Philippines is not yet fully understood and documented, and this is derived only from a few studies. In this paper, we present our single-event observation of an ectoparasite interaction between C. dentata and the Asian turtle tick (Amblyomma geoemydae) from Sitio Malbato, Barangay Bintuan Coron, Palawan. Our discovery serves as the second documented instance of this ectoparasite on C. dentata in the Philippines, hence extending its known distribution outside mainland Palawan. This finding contributes to the limited understanding of C. dentata's ecology and underscores the need for further field-based observations, which are crucial for their research and conservation. [ABSTRACT FROM AUTHOR]

Determining activity rhythms is crucial for understanding the life history, ecology, and evolution of an animal species. Due to various anthropogenic threats, wild populations of Reeves' turtle (Mauremys reevesii) are diminishing throughout its geographic range in East Asia. Despite the endangered conservation status of this species, little is known about its activity rhythm. Therefore, the focus of this study was to radio track 23 wild Reeves' turtles in the field to determine their daily and seasonal activity patterns. We identified the Reeves' turtle as both diurnal and nocturnal, rather than the traditional classification of diurnal, with an average daily activity peak between 1800 and 2000 hours. In spring, the frequency of diurnal activity was higher than that of nocturnal activity, and males were significantly more active than females. In summer, total activity frequency increased significantly and was predominantly nocturnal, with no significant difference in activity found between males and females. In autumn, nocturnal activity decreased and males were significantly more active than females overall. Reeves' turtles hibernated from the end of October to mid-April. Our results elucidate the daily and seasonal activity rhythms of Reeves' turtles, thus providing a reference for understanding the life history of the species and potentially improving future conservation planning. [ABSTRACT FROM AUTHOR]

Knowledge about the distributions of species and the variables influencing their occurrence is important for their management and conservation, but factors affecting occurrence can vary across the range of a species. Northwestern pond turtles (Actinemys marmorata) are widespread generalist turtles, but are nonetheless of conservation concern throughout their range. To better understand the distribution of northwestern pond turtles and introduced American bullfrogs (Lithobates catesbeianus), we surveyed streams on private timberlands of the interior foothills of northern California using visual encounter surveys and collecting samples of environmental DNA. We found that northwestern pond turtle occurrence was negatively related to elevation in our sampling frame. Detection probabilities with environmental DNA were approximately twice those of visual encounter surveys, but both methods were effective for detecting turtles in streams. American bullfrogs were detected in a single sample at each of 2 sites (one by environmental DNA, one by visual encounter surveys). Management for northwestern pond turtles in forest streams within our sample area will likely have the largest effect at lower elevation sites where turtles are most likely to occur. [ABSTRACT FROM AUTHOR]

Many freshwater turtles in the United States are considered species of greatest conservation need in the states in which they occur, including turtles in the genus Graptemys (map turtles and sawbacks). However, basic life-history information is still lacking for many Graptemys species, particularly details about their movements, home range, and habitat use. The objective of this study was to describe linear activity area (LAA) and basking-site fidelity for 2 federally threatened Graptemys species in Mississippi (Graptemysflavimaculata, Graptemys oculifera) via capture–mark–recapture events. For G. flavimaculata, 97 individuals (30 female, 67 male) were recaptured during the study at 3 sites. Mean LAA for females (138 ± 293 m; 0–1489 m) and males (308 ± 637 m; 0–3773 m) was statistically similar, but turtle LAAs from 2 upstream sites were longer than LAAs from a downstream site. The maximum single movement was 2877 m by a male; alternatively, many males and females were recaptured at the same basking log across multiple years. For G. oculifera, 28 individuals (14 female, 14 male) were recaptured during the study at 1 site and mean LAAs were statistically similar for females (130 ± 206 m; 4.6–747 m) and males (231 ± 357 m; 0–1310 m). Differences in LAAs among sites for G.flavimaculata may be associated with habitat differences observed among the sites (i.e., river size, hydrology, position on river continuum) or associated with different turtle densities. Basking-site fidelity appears to be strong in both species and is likely driven by deadwood persistence time and/or sexually divergent preferences in basking sites. Additional movement ecology studies are needed for Graptemys species to determine how differences in habitat, turtle densities, and deadwood interact to influence linear home ranges. [ABSTRACT FROM AUTHOR]

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 long-lived species. [ABSTRACT FROM AUTHOR]

The Scorpion Mud Turtle (Kinosternon scorpioides) has been recognized by most recent authors to be a single species (3 subspecies) ranging from Tamaulipas, Mexico, to northern Argentina. However, recent molecular analyses have demonstrated that it is not monophyletic, but rather paraphyletic relative to other Neotropical Kinosternon. Based on extensive genetic sampling across the range of this species, a recent paper elevated the 3 subspecies (albogulare, cruentatum, and scorpioides) to species status, confirmed the divergence of Pacific and Atlantic versant populations of K. cruentatum, and recommended that both be given species status. However, the type locality of K. cruentatum is imprecise, making the allocation of the name problematic. Our study sought to determine the provenance of the type using morphometric analysis of specimens from across the range. That analysis demonstrates unequivocally that the type of K. cruentatum was collected on the Atlantic versant, likely from an eastern population. Furthermore, the analysis also revealed that the type of K. mexicanum, previously synonymized with K. cruentatum, was collected from along the Pacific versant. Hence, the name K. cruentatum should be restricted to populations in Atlantic drainages, and the name K. mexicanum should be restricted to Pacific drainages. Our analysis also indicated divergence among the 3 allopatric Atlantic versant populations, but future genetic work will be needed to determine whether they merit taxonomic recognition. [ABSTRACT FROM AUTHOR]

The savannah side-necked turtle Podocnemis vogli is a species restricted to the savannas of the Orinoco basin in Colombia and Venezuela. Because of its apparent abundance, it is currently categorized as Least Concern (LC) by the IUCN Red List. However, throughout its distribution range, several populations have been extirpated or individuals in remaining populations are consumed and trafficked, and the species' habitat has been highly degraded. To start assessing the conservation status of the species, 5 populations along their distribution range in Colombia were analyzed using 19 microsatellite loci to perform a population genetics study. Ten of those markers were useful in revealing (1) high levels of genetic diversity, (2) a marked genetic structure of 5 populations, and (3) low and asymmetric gene flow among them. However, the analyses also revealed the loss of genetic diversity (low allelic richness) and recent bottlenecks in some populations. Those identified detrimental indicators are evidencing a population decline most likely related to anthropic activities. These 5 populations correspond to 5 independent management units. The results of this research allow us to propose management and conservation guidelines for these populations in the Orinoco ecoregion. Resumen La tortuga sabanera Podocnemis vogli es una especie restringida a las sabanas de la cuenca del Orinoco en Colombia y Venezuela. Debido a su aparente abundancia, actualmente está categorizada como en Preocupación Menor (LC) por la Lista Roja de la UICN. Sin embargo, a lo largo de su rango de distribución, varias poblaciones han sido extirpadas o los individuos en poblaciones remanentes son consumidos y traficados, y el hábitat de la especie se ha degradado intensamente. Para comenzar a evaluar el estado de conservación de la especie, se analizaron cinco poblaciones a lo largo de su rango de distribución en Colombia utilizando 19 loci microsatélites para realizar un estudio de genética poblacional. Diez de esos marcadores fueron útiles para revelar: (1) altos niveles de diversidad genética, (2) una estructura genética marcada de cinco poblaciones y (3) flujo de genes bajo y asimétrico entre ellas. Sin embargo, los análisis también revelaron la pérdida de diversidad genética (baja riqueza alélica) y cuellos de botella recientes en algunas poblaciones. Esos indicadores perjudiciales identificados están evidenciando una disminución de las poblaciones, muy probablemente relacionada con las actividades antrópicas. Estas cinco poblaciones corresponden a cinco Unidades de Manejo Independientes. Los resultados de esta investigación nos permiten proponer lineamientos de manejo y conservación para estas poblaciones en la ecorregión del Orinoco. [ABSTRACT FROM AUTHOR]

Understanding which factors make an individual susceptible to parasitism provides insight on how a parasite infects a host. Numerous factors such as habitat characteristics, body size, and sex have shown differential impacts on parasitism rates. Trends in parasitism rate often exist for similar taxonomic groups, so expanding research to new species helps test the robustness of such trends. A chelonian-specific ectoparasite, Cistudinomyia cistudinis (Diptera: Sarcophagidae), has been documented in case studies dating back a century. Almost all reports of infection by this flesh fly are of a single or few turtles, so there is a lack of information regarding the population dynamics of infection. This lack of information means little is known about which factors make a turtle more or less likely to be parasitized. In this work, we compared the occurrences of parasitism in ornate box turtle (Terrapene ornata) populations across multiple seasons from 2 different habitats in northeastern Kansas (North Topeka and Lawrence). At the population level, we found a significantly higher number of parasitized turtles in the Lawrence population. Within the Lawrence population, we found females were more likely to be parasitized. This study sets baseline infection rates for a long-lived vertebrate host that can help better understand the reasons for parasitism both among and within populations. [ABSTRACT FROM AUTHOR]

The Euphrates soft-shell turtle Rafetus euphraticus is classified as endangered on the IUCN Red List and is thought to have recently undergone large population declines. Species information in Iraq is limited to a few rapid surveys with little detailed information on its breeding and distribution. Turtles have been recorded inside the water by setting nets in certain areas in the Central Marshes. Morphometric measurements were recorded in Euphrates soft-shelled turtles Rafetus euphraticus, sampled in the Central Marshes. According to nine morphometric ratios, the populations of R. euphraticus in the Central Marshes are smaller in size than previous specimens that have been recorded in neighboring countries. The carapaces length (CL) rang for current study was 70 to 560 mm, whereas it was 187 to 680 mm according to a previous study. The carapaces width (CW) rang for the current study was 63 to 420 mm, while in a previous study it was recorded to be 152 to 465 mm. [ABSTRACT FROM AUTHOR]

Species of Haemogregarina are blood parasites known to parasitise vertebrate hosts, including fishes (Haemogregarina sensu lato) and freshwater turtles (Haemogregarina sensu stricto). Their vectors, include gnathiid isopods and leeches, respectively. In turtles, Haemogregarina balli has the best-characterized life cycle in the genus. However, no studies in Brazil have suggested a possible vector for any species of Haemogregarina from freshwater turtles. Therefore, in the present study, we provide insights into a leech vector based on specimens found feeding on two species of freshwater turtles, Podocnemis unifilis and Podocnemis expansa, using morphological and molecular data. In 2017 and 2019, freshwater turtles were collected in Goiás State, Brazil. Hosts were inspected for ectoparasites and leeches were collected from two specimens of P. expansa and nine specimens of P. unifilis. Leeches were subsequently identified as members of the genus Unoculubranchiobdella. Leech histological slides revealed haemogregarine-like structures, similar to post-sporogonic merogony, found near the gills and within the posterior sucker. Molecular analysis of the haemeogregarines resulted in the identification of three species of Haemogregarina: Haemogregarina embaubali, Haemogregarina goianensis, and Haemogregarina brasiliana. Therefore, our findings, based on morphology and DNA data suggest leeches of the genus Unoculubranchiondella as vectors for at least three species of Haemogregarina from Brazilian turtles. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia is a gram-negative bacterium that can be routinely identified in the aquatic environment, and has become an emergent, multi-drug-resistant life-threatening organism in some circumstances. This bacterium was identified as a presumptive causative agent in cases of polysystemic granulomatous disease in one diamondback terrapin (Malaclemys terrapin) and one mata mata (Chelus fimbriata). Both chelonians presented with lethargy, hyporexia, and multifocal subcutaneous masses diagnosed by physical examination and in one individual on computed tomography (CT). The primary hematologic finding was moderate to severe heterophilic leukocytosis, and both turtles were treated with a combination of supportive care, systemic antibiotics, and/or surgical resection of subcutaneous masses. Medical and surgical management were unsuccessful, and one patient was euthanized and the other found deceased. Necropsies revealed multisystemic granulomas, and cultures identified growth of Stenotrophomonas maltophilia. A postmortem investigation into possible risk factors identified comorbidities including shell disease, repeated administration of injectable antibiotics, low environmental temperature, and aquatic pH changes as possible contributing factors. This bacterium appears to be an emerging organism of concern and should be considered as a potential cause of granulomas in aquatic chelonians. [ABSTRACT FROM AUTHOR]