Terrapene Carolina Triunguis Research Articles

Microbiome resilience of three-toed box turtles (Terrapene carolina triunguis) in response to rising temperatures.

The gastrointestinal (GI) microbiome of chelonians (testudines) plays an important role in their metabolism, nutrition, and overall health but the GI microbiome of three-toed box turtles (Terrapene carolina triunguis) has yet to be characterized. How the GI microbiome responds to rapidly rising environmental temperatures has also not been studied extensively in ectotherms, specifically chelonians. In this study, twenty (20) T.c.triunguis were split into control and experimental groups. The experimental group experienced 4.5°C increases every two weeks while the control group stayed at a constant ambient temperature (24°C) through the entirety of the experiment. Before each temperature increase, all turtles had cloacal swab samples taken. These samples underwent DNA extraction followed by 16S rRNA gene sequencing and microbial community analyses. Differences in diversity at the community level in the controls compared to the experimental groups were not statistically significant, indicating microbiome resilience to rapid temperature changes in T.c.triunguis, although some differentially abundant lineages were identified. Interestingly, an amplicon sequence variant belonging to the Erysipelothrix spp. was exclusively enriched in the highest temperature group relative to controls. Overall, our work suggests that there may be an innate robustness to rapid temperature swings in the microbiome of T.c.triunguis which are native to temperate North America. Despite this resilience, Erysipelothrix spp. was enriched at the highest temperature. Phylogenetic analysis of this amplicon variant showed that it is a close relative of Erysipelothrix rhusiopathiae, a pathogen of zoonotic importance associated with both wildlife and livestock.

Diagnosis of Orthopedic Fractures Using Craniodorsal-Caudoventral Oblique and Caudodorsal-Cranioventral Oblique Radiographic Views Made at 45° to the Frontal Plane in Four Wild Turtles

Abstract 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 and/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 (dorsoventral, right lateral, and 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 and/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 as 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.

Evaluating translocation strategies for box turtles in urbanising landscapes

Context Translocation is a common management strategy for wildlife populations, yet hard-release of reptiles, including box turtles (Terrapene spp.), has often proven ineffective due to homing attempts and wandering. Soft-release translocation has been presented as a possible method for mitigation of the negative effects of hard-release translocation, but studies incorporating standard soft-release strategies have produced mixed results and often see persistent homing attempts by soft-released study animals. Aims The aim of this study was to examine long-term holding (>1 year) of box turtles at an off-site location prior to translocation as a means to reduce homing attempts and wandering commonly observed in immediate-release box turtles. Methods We radiotracked translocated Terrapene carolina triunguis to compare movements of nine immediate-release box turtles and nine box turtles that had been maintained for >1 year at a nearby off-site holding facility (long-term holding) prior to a 750–1000 m translocation. Key results Box turtles held long-term before a short-distance translocation moved significantly shorter distances each day post-release than immediate-release turtles. Turtles held long-term moved in non-directional, random orientations, whereas immediate-release turtles exhibited consistent directionality in movements back towards their initial capture (home) locations. Conclusions Our results demonstrated that turtles held off-site remained within the translocation site more reliably than the immediate-release turtles, which had a higher tendency to home. Implications Long-term holding of turtles prior to translocation could significantly reduce homing responses and wandering, thus increasing translocation efficacy while reducing intensity of post-translocation management.

Ranavirus (Frog Virus 3) Infection in Free-Living Three-Toed Box Turtles (Terrapene mexicana triunguis) in Missouri, USA.

Frog virus 3 (FV3) and related ranaviruses are emerging infectious disease threats to ectothermic vertebrate species globally. Although the impact of these viruses on amphibian health is relatively well studied, less is understood about their effects on reptile health. We report two cases of FV3 infection, 11 mo apart, in three-toed box turtles (Terrapene mexicana triunguis) from a wildlife rehabilitation center. Case 1 had upper respiratory signs upon intake but had no clinical signs at the time of euthanasia 1 mo later. Case 2 presented for vehicular trauma, had ulcerative pharyngitis and glossitis, and died overnight. In case 1, we detected FV3 nucleic acid with qPCR in oral swabs, kidney, liver, spleen, and tongue. In case 2, we detected FV3 in an oral swab, an oral plaque, heart, kidney, lung, liver, spleen, and tongue. We also detected FV3 nucleic acid with in situ hybridization for case 2. For both cases, FV3 was isolated in cell culture and identified with DNA sequencing. Histopathologic examination of postmortem tissue from case 1 was unremarkable, whereas acute hemorrhagic pneumonia and splenic necrosis were noted in case 2. The difference in clinical signs between the two cases may have been due to differences in the temporal course of FV3 disease at the time of necropsy. Failure to detect this infection previously in Missouri reptiles may be due to lack of surveillance, although cases may also represent a novel spillover to box turtles in Missouri. Our findings reiterate previous suggestions that the range of FV3 infection may be greater than previously documented and that infection may occur in host species yet to be tested.

Home ranges of box turtles in a rural woodland and an urban park in Saint Louis, MO; implications for turtle conservation

The negative consequences of fragmentation, infrastructure development, and urbanization on biodiversity are well known. However, careful urban planning can provide viable habitat for some species and communities. Generally, r-selected species are more likely to persist in urbanizing landscapes, while long lived, mobile species, such as turtles, are likely to decline toward extinction. Understanding species responses across urban gradients is important for developing mitigation planning. We used VHF telemetry to quantify ranging behavior of three-toed box turtles in fragmented urban forest patches and a semi-contiguous large rural forest in Saint Louis, Missouri. We then simulated movement trajectories based on empirical data from the two turtles with the largest and smallest home ranges, overlaid on forest cover and road network maps of Missouri, to quantify the state-wide probability of turtles encountering roads. Home range (HR) size varied from 1–250Ha. The mean home range estimate of rural turtles was > 9 times larger than that of urban turtles. Simulations indicated that the least mobile turtle (HR 1Ha) would have a 22% likelihood of encountering a road if placed randomly in suitable habitat anywhere in the state. The likelihood increased to 90% for the most mobile turtle (HR 250Ha), with 10 road crossings per year. High turtle mortality, range restriction and population fragmentation are likely even in rural areas. In urban cityscapes, large, roadless forest patches offer the highest conservation potential for this species.

Effects of Prairie Degradation and Restoration on Box Turtle Thermal Ecology

Prairie habitat loss in the United States has led to population declines in many prairie-associated species, including Ornate Box Turtles (Terrapene ornata). Northwest Arkansas is an intergrade zone between the prairie-dwelling T. ornata and the more forest-associated Three-Toed Box Turtle (Terrapene carolina). As such, limited information exists on the potential differences in physiology and thermal ecology between the two box turtle species and how those differences might influence their habitat use. We addressed gaps in our knowledge of the thermal and spatial ecology of T. ornata and T. carolina with a three-part study. First, we compared the thermal profiles of refugia, open, and vegetated microhabitats across degraded prairie, restored prairie, and adjacent forest macrohabitats using operative temperature models and a linear mixed effect model. Second, we measured total evaporative water loss of both species across a range of body sizes. Finally, we fitted a subset of turtles with iButton data loggers and monitored them in the field to examine carapace temperatures and habitat use. Operative temperature models recorded high, largely homogeneous temperatures across microhabitats in degraded prairie and heterogeneous temperatures across restored prairie microhabitats, while forest habitat maintained stable, cool temperatures. Both species exhibited similar evaporative water loss rates; however, T. ornata experienced a broader range of temperatures in the field. Terrapene ornata were exclusively found in prairie habitat, whereas T. carolina was often found in forested habitats and subsurface refugia. Our results demonstrate key differences in box turtle thermal biology and highlight suboptimal thermal characteristics in degraded prairie and forest habitat that should be considered in prairie restoration and management for T. ornata conservation.

Quantifying visual acuity of Terrapene carolina triunguis utilizing optokinetic response.

Quantify visual acuity of a semi-aquatic turtle species, Terrapene carolina triunguis (three-toed box turtles), utilizing optokinetic response/reflex/nystagmus. Ten turtles were placed on a custom platform and an image of white and black gratings of varying sized widths was projected onto a white screen in front of the turtles. Optokinetic response (OKR) was observed through a web camera as well as physically by an observer. The grating sizes were decreased until OKR could not be elicited. The size of grating was recorded and was used to calculate visual acuity. The average visual acuity was 0.26 cycle per degree (cpd) with the highest recorded value being 0.43 cpd and lowest being 0.15 cpd. Neither sex nor weight were significantly associated with visual acuity (p=.24 and .98, respectively). Visual acuity of these semi-aquatic turtles was much lower than previously reported visual acuities of aquatic turtles. This could be due to differences in refractive indices between water and air, behavioral adaptations for the different species and/or method of obtaining visual acuity.

A novel herpesvirus detected in 3 species of chelonians.

Herpesviruses are found in free-living and captive chelonian populations, often in association with morbidity and mortality. To date, all known chelonian herpesviruses fall within the subfamily Alphaherpesvirinae. We detected a novel herpesvirus in 3 species of chelonians: a captive leopard tortoise (Stigmochelys pardalis) in western TX, USA; a steppe tortoise (Testudo [Agrionemys] horsfieldii) found near Fort Irwin, CA, USA; and 2 free-living, three-toed box turtles (Terrapene mexicana triunguis) found in Forest Park, St. Louis, MO. The leopard tortoise was coinfected with the tortoise intranuclear coccidian and had clinical signs of upper respiratory tract disease. The steppe tortoise had mucopurulent nasal discharge and lethargy. One of the three-toed box turtles had no clinical signs; the other was found dead with signs of trauma after being observed with blepharedema, tympanic membrane swelling, cervical edema, and other clinical signs several weeks prior to death. Generally, the branching order of the turtle herpesviruses mirrors the divergence patterns of their hosts, consistent with codivergence. Based on phylogenetic analysis, this novel herpesvirus clusters with a clade of viruses that infect emydid hosts and is likely of box turtle origin. Therefore, we suggest the name terrapene alphaherpesvirus 3 (TerAHV3) for the novel virus. This virus also has the ability to host-jump to tortoises, and previously documented herpesviral morbidity tends to be more common in aberrant hosts. The relationship between clinical signs and infection with TerAHV3 in these animals is unclear, and further investigation is merited.

Fire management alters the thermal landscape and provides multi-scale thermal options for a terrestrial turtle facing a changing climate.

As effects of climate change intensify, there is a growing need to understand the thermal properties of landscapes and their influence on wildlife. A key thermal property of landscapes is vegetation structure and composition. Management approaches can alter vegetation and consequently the thermal landscape, potentially resulting in underappreciated consequences for wildlife thermoregulation. Consideration of spatial scale can clarify how management overlaid onto existing vegetation patterns affects thermal properties of landscapes relevant to wildlife. We examined effects of temperature, fire management, and vegetation structure on multi-scale habitat selection of an ectothermic vertebrate (the turtle Terrapene carolina triunguis) in the Great Plains of the central United States by linking time-since-fire data from 18 experimental burn plots to turtle telemetry locations and thermal and vegetation height data. Within three 60-ha experimental landscapes, each containing six 10-ha sub-blocks that are periodically burned, we found that turtles select time-since-fire gradients differently depending on maximum daily ambient temperature. At moderate temperatures, turtles selected sub-blocks with recent (<1year) time-since-fire, but during relatively hot and cool conditions, they selected sub-blocks with later (2-3year) time-since-fire that provided thermal buffering compared with recently burned sub-blocks. Within 10-ha sub-blocks, turtles selected locations with taller vegetation during warmer conditions that provided thermal buffering. Thermal performance curves revealed that turtle activity declined as temperatures exceeded ~24-29°C, and on "heat days" (≥29°C) 73% of turtles were inactive compared with 37% on non-heat days, emphasizing that thermal extremes may lead to opportunity costs (i.e., foregone benefits turtles could otherwise accrue if active). Our results indicate that management approaches that promote a mosaic of vegetation heights, like spatiotemporally dynamic fire, can provide thermal refuges at multiple spatial scales and thus be an actionable way to provide wildlife with multiple thermal options in the context of ongoing and future climate change.

Mortality in Three-Toed Box Turtles (Terrapene mexicana triunguis) at Two Sites in Missouri.

Once ubiquitous, North American box turtles are experiencing reductions in abundance and range, but the magnitude of these losses is largely unknown. In Missouri, native box turtles (Terrapene mexicana triunguis and Terrapene ornata ornata) are declining across the state due to anthropogenic disturbances such as urbanization, habitat fragmentation, and vehicle collisions. Through radio-tracking over a period of 7 years, we documented the survival of adult three-toed box turtles at two sites in Missouri: Forest Park (urban park) and Tyson Research Center (TRC) (a protected rural forest). Estimated annual survival of adult turtles in Forest Park was 79% (95% CI: 0.68–0.87) while at TRC annual survival was 93% (95% CI: 0.83–0.97). The odds of annual survival for a turtle at TRC were 3.5 times that of a turtle living in Forest Park. “Winter kill,” which refers to box turtles found dead on the surface during brumation or within 2 weeks of emergence, was the most frequently documented category of mortality in Forest Park. At TRC, winter kill was not documented; however, the reasons for most deaths were unknown. These data raise questions about the potential of large urban parks as refuges for box turtles, which we may answer by future studies that compare box turtles living in multiple urban and rural settings. Our preliminary data suggest that even the largest urban parks may not be able to sustain populations of box turtles which has severe implications as urbanization continues to degrade and eliminate box turtle habitat throughout their range.

A QUANTITATIVE PCR ASSAY FOR A MYCOPLASMA FROM EMYDID TURTLES INDICATES HIGH PREVALENCE IN HEALTHY THREE-TOED BOX TURTLES (TERRAPENE CAROLINA TRIUNGUIS) FROM MISSOURI, USA

We evaluated cause of injury and quantified levels of three potential mycoplasmal pathogens (Mycoplasma agassizii, Mycoplasma testudineum, and an emydid mycoplasma) in three-toed box turtles (Terrapene carolina triunguis) from the greater St. Louis, Missouri, US area, brought to and housed at the Wildlife Rescue Center (Ballwin, Missouri, US) in 2015 and 2016. We created a probebased quantitative PCR (qPCR) assay for the emydid mycoplasma, with a similar specificity and sensitivity as the existing qPCR assays for M. agassizii and M. testudineum. All three microbes have been implicated in the development of upper respiratory tract disease in turtles and tortoises. We assessed whether signs of respiratory disease, sex, type of trauma, or treatment (administration of antibiotics) affected the presence of pathogens. We found that the most common types of injury experienced by turtles (n=85) were due to motor vehicles and other types of machinery, and that injuries due to motor vehicles were the most severe. We found a 61% prevalence of emydid mycoplasma (n=28) but M. agassizii or M. testudineum were not detected. Prevalence of disease and antibiotic treatment was too low to statistically relate to levels of mycoplasma. Sex and type of trauma were not associated with levels of emydid mycoplasma. The box turtle population we sampled did not experience signs of respiratory disease due to the fairly widespread prevalence of emydid mycoplasma. However, mycoplasmal diseases can be pathogen load-dependent. The qPCR we designed can be used to assess levels of emydid mycoplasma in other emydid species, populations, and individuals, in which there might be a positive association between the microbe and expression of respiratory disease.

Clinical Mycoplasma sp. Infections in Free-living Three-toed Box Turtles ( Terrapene carolina triunguis) in Missouri, USA.

Mycoplasma species, which can cause upper respiratory tract disease (URTD), are significant pathogens of birds, mammals, fish, and reptiles. Mycoplasmosis is of high concern for chelonian conservation, with the most well-documented cases in gopher and desert tortoises. Mycoplasma sp. infections have been reported in captive and free-living box turtles ( Terrapene spp.). We documented URTD associated with Mycoplasma sp. in two free-living, three-toed box turtles ( Terrapene carolina triunguis) in Missouri, US. Both turtles were Mycoplasma sp. positive by PCR and had URTD-like clinical signs, including nasal and ocular discharge, palpebral edema, lethargy, and weight loss, during a 6-8-wk period between June and September 2014.

Demographics and density estimates of two three-toed box turtle (Terrapene carolina triunguis) populations within forest and restored prairie sites in central Missouri

Box turtles (Terrapene carolina) are widely distributed but vulnerable to population decline across their range. Using distance sampling, morphometric data, and an index of carapace damage, we surveyed three-toed box turtles (Terrapene carolina triunguis) at 2 sites in central Missouri, and compared differences in detection probabilities when transects were walked by one or two observers. Our estimated turtle densities within forested cover was less at the Thomas S. Baskett Wildlife Research and Education Center, a site dominated by eastern hardwood forest (d = 1.85 turtles/ha, 95% CI [1.13, 3.03]) than at the Prairie Fork Conservation Area, a site containing a mix of open field and hardwood forest (d = 4.14 turtles/ha, 95% CI [1.99, 8.62]). Turtles at Baskett were significantly older and larger than turtles at Prairie Fork. Damage to the carapace did not differ significantly between the 2 populations despite the more prevalent habitat management including mowing and prescribed fire at Prairie Fork. We achieved improved estimates of density using two rather than one observer at Prairie Fork, but negligible differences in density estimates between the two methods at Baskett. Error associated with probability of detection decreased at both sites with the addition of a second observer. We provide demographic data on three-toed box turtles that suggest the use of a range of habitat conditions by three-toed box turtles. This case study suggests that habitat management practices and their impacts on habitat composition may be a cause of the differences observed in our focal populations of turtles.

Coccidia (Apicomplexa: Eimeriidae) of Three-toed Box Turtles, Terrapene carolina triunguis (Reptilia: Testudines), from Arkansas and Oklahoma

We collected 50 three-toed box turtles (Terrapene carolina triunguis) from 9 counties of Arkansas and 4 counties of Oklahoma, and examined their feces for coccidial parasites. Nine of 24 (38%) turtles from Arkansas and 8 of 26 (31%) from Oklahoma were found to be passing oocysts of Eimeria ornata. This represents two new geographic distributional records for this coccidian. Measurements of individual isolates of E. ornata as well as morphological characteristics are provided with comparison to its original description and to another Terrapene coccidian, Eimeria carri. In addition, we noted an adelid pseudoparasite being passed by a single T. c. triunguis from Oklahoma that likely represents a parasite of arthropods.

Comparative Histology, Histochemistry, and Ultrastructure of Rathke's Glands in Hatchlings of Two Species of North American Box Turtles (Terrapene carolinaandTerrapene ornata)

We examined the histology, histochemistry, and ultrastructure of Rathke's glands in hatchlings of the three-toed box turtle, Terrapene carolina triunguis, and the desert box turtle, Terrapene ornata luteola. Both species possess one pair (axillary) of Rathke's glands, which are similar anatomically and histochemically to one another. Each gland is composed of a single, highly vascularized secretory lobule, which is surrounded by a thick sheath of striated muscle. Two types of large secretory vacuoles characterize most of the holocrine cells produced by a relatively thin glandular secretory epithelium. Analysis of our results suggests that the chief secretory material of the smaller dark-staining type 1 secretory vacuole appears to be a glycoprotein complex. The larger, mostly translucent type 2 secretory vacuole contains multilayered and variously sized lamellar bodies, whose structural design is reminiscent of an epidermal lipid delivery system in vertebrates. The functional role of Rathke's glands in Terrapene and in other turtles remains unclear at the present time.

Seasonal Occurrence of Activity and Reproduction of the Three-Toed Box Turtle (Terrapene Carolina Triunguis) in East Texas

North American box turtles (Terrapene spp.) typically demonstrate localized activity patterns that are highly dependent on temperature and precipitation. In east Texas, we found no documented reports of activity patterns, clutch sizes, sex ratios, or ratios of gravid to non-gravid females in T. Carolina triunguis. Here, we report data on the monthly occurrence and reproductive status for a population of T. c. triunguis in Walker County, Texas. We used a volunteer sampling protocol to investigate when males and females were most active. April and May had the greatest frequency of captures while June and July had the least. Captures were slightly male-biased (1.6 males: 1 female) and the first gravid female was collected on April 29. About half (54%) of all females x-rayed were gravid with clutch sizes ranging from one to five eggs. The variation in the clutch size of eggs is explained by female body mass with larger females having larger clutches of eggs. The activity and reproductive patterns reported here are similar to those patterns documented in past studies and other Terrapene populations, but provide what may prove to be useful natural history information for an urban population of T. c. triunguis.

Isolation and characterization of polymorphic microsatellite loci for the three‐toed box turtle (Terrapene carolina triunguis) and cross‐amplification in other Terrapene species

We isolated and characterized eight polymorphic microsatellite loci for a Texas population of three-toed box turtle, Terrapene carolina triunguis, using a refined hybridization capture procedure. All eight primer pairs amplified successfully at all loci in seven Texas ornate box turtles (T. ornata ornata). Due to the decline and conservation concerns of North American box turtles, these isolated microsatellites may be a most valuable tool for evaluating baseline population genetic structure for threatened box turtle populations.

Predicted climate change may spark box turtle declines

AbstractHow will organisms deal with Climate change? Ectotherms such as reptiles and amphibians are especially at risk due to their metabolic ties to the environment and their general inability to migrate with changing climates over short time frames. We modeled the growth response of Three-toed Box Turtles (Terrapene carolina triunguis) to fluctuations in ambient temperature and precipitation. Then we extrapolated this model to climate conditions expected in 2100. We predict that there is less than 20% possibility of hatchling turtles growing during their first year. Reduced annual growth rates during later years may cause earlier termination of growth, smaller standard carapace lengths, and reduced fecundity. These responses are typical of those that stimulate an extinction vortex. These findings provide for a general understanding of how this species and other terrestrial reptiles may respond to climate change. Without reduction in greenhouse gas emissions we could face catastrophic declines in many ectotherms as temperature and rainfall patterns change.

Nesting Behavior in Three-Toed Box Turtles(Terrapene carolina triunguis) Following Oxytocin-Induced Oviposition

ABSTRACT Between 1997 and 2001, we observed nesting behavior following oxytocin-induced oviposition in 10 three-toed box turtles. Oviposition preceded nesting behavior by 0.5–17 days. Three turtles oviposited subsequent clutches (without oxytocin induction) a mean of 30 days after the oxytocin injections but only 22 days after they constructed empty nests. The mean internesting interval was 21 days between consecutive ovipositions without oxytocin induction by these 3 females in the same and subsequent seasons.

Resource Selection by Translocated Three‐Toed Box Turtles in Missouri

Abstract Resource selection is a multi‐staged process of behavioral responses to various resource cues or stimuli. Previous research suggests some aspects of resource selection may be inherent (i.e., genetic predisposition) or based on early experience and that individuals respond to certain resource cues but not to others. In other words, resource selection may be based on a template that specifies which cues to use in the resource‐selection process and the appropriate response to those cues. We used resource utilization functions (RUFs) to examine the resource‐selection template of translocated three‐toed box turtles (Terrapene carolina triunguis; hereafter turtles) and made comparisons to resident turtles. Translocated turtles, previously residents of a predominantly forested landscape with low edge‐density, used forest openings, forest edges, and southwest‐facing slopes before and after translocation to a fragmented site containing resident turtles. In contrast, resident turtles used forested areas and northeast‐facing slopes within a predominantly open landscape with high edge‐density. Our comparison of resource selection by translocated and resident turtles revealed population‐specific resource selection and consistency in selection following translocation, which reinforces the idea of a resource‐selection template and suggests that in the short‐term box turtles may not adapt their predisposed behavior to local conditions. Thus, translocated animals may evaluate and respond to resource cues as if they were at the original site. Lack of site fidelity may result from individuals seeking additional resources to match their resource‐selection template. Successful translocation of turtles may require an assessment of resource selection prior to translocation and development of management strategies that mitigate turtle response to translocation.