Terrapene Research Articles

Ecología espacial y direccionalidad de hembras de Terrapene coahuila en el valle de Cuatro Ciénegas, Coahuila, México

An understanding of the spatial ecology of the Coahuilan box turtle is critical for the development of successful habitat conservation strategies for this imperiled species. Regrettably, the spatial ecology of this species is poorly understood. We monitored the daily movements of 7 females Coahuilan box turtles from August to October 2014 and 12 female turtles from April to June 2015, in the wetland Los Gatos, inside of Cuatro Ciénegas valley. We estimated home range size using both minimum convex polygon and 95% fixed Kernel. Core activity areas were estimated by 50% fixed Kernel. Directionality was estimated by Rao's test to evaluate mean directionality of movements (locations) in relationship with the center of activity. Minimum convex polygon home ranges were different for the 2 sampling periods, while 95% fixed Kernel showed no differences between the 2 sampling periods. The 50% fixed Kernel core activity areas also did not show differences between the sampling periods. Moreover, female Terrapene coahuila movements did not make random during either sampling period. Our home range analyses indicate that the species occupies larger areas than estimated by previous authors. Habitat conservation for this species must consider the connectivity of the ponds in the Los Gatos study area.

Diagnosis and treatment of a multidrug-resistant Escherichia coli in a wild eastern box turtle (Terrapene carolina carolina)

An adult male eastern box turtle presented to the Turtle Rescue Team at North Carolina State University with clinical signs of an upper respiratory tract infection. After unsuccessful treatment with...

Ecomorphological correlates of microhabitat selection in two sympatric Asian Box Turtle species (Geoemydidae: Cuora)

Closely related species that co-occur in homogeneous environments often possess differing morphologies, which can result in niche divergence that minimizes interspecific competition. In the present study, we examined the relationship between ecomorphological characteristics and microhabitat selection of two Asian box turtle species, the Keeled Box Turtle (Cuora mouhotii (Gray, 1862)) and the Indochinese Box Turtle (Cuora galbinifrons Bourret, 1940), that have sympatric distributions in the rainforest of Hainan, People’s Republic of China. We found that C. mouhotii had a relatively flat shell and preferred microhabitats with rock crevices and steep slopes in the field, whereas C. galbinifrons had a domed shell and was restricted to microhabitats of deciduous leaves under bamboo growing on gentle slopes. We conclude that morphological divergence allows the two Cuora spp. to use different microhabitats and, thereby, to successfully co-occur.

Thermal biology of eastern box turtles in a longleaf pine system managed with prescribed fire

Fire can influence the microclimate of forest habitats by removing understory vegetation and surface debris. Temperature is often higher in recently burned forests owing to increased light penetration through the open understory. Because physiological processes are sensitive to temperature in ectotherms, we expected fire-maintained forests to improve the suitability of the thermal environment for turtles, and for turtles to seasonally associate with the most thermally-optimal habitats. Using a laboratory thermal gradient, we determined the thermal preference range (Tset) of eastern box turtles, Terrapene carolina, to be 27–31°C. Physical models simulating the body temperatures experienced by turtles in the field revealed that surface environments in a fire-maintained longleaf pine forest were 3°C warmer than adjacent unburned mixed hardwood/pine forests, but the fire-maintained forest was never of superior thermal quality owing to wider Te fluctuations above Tset and exposure to extreme and potentially lethal temperatures. Radiotracked turtles using fire-managed longleaf pine forests maintained shell temperatures (Ts) approximately 2°C above those at a nearby unburned forest, but we observed only moderate seasonal changes in habitat use which were inconsistent with thermoregulatory behavior. We conclude that turtles were not responding strongly to the thermal heterogeneity generated by fire in our system, and that other aspects of the environment are likely more important in shaping habitat associations.

MORBIDITY AND MORTALITY OF WILD TURTLES AT A NORTH CAROLINA WILDLIFE CLINIC: A 10-YEAR RETROSPECTIVE.

The medical records from 1,847 wild turtle patients seen between 2005 and 2014 by the Turtle Rescue Team at the North Carolina State University College of Veterinary Medicine were analyzed. Eastern box turtles (Terrapene carolina carolina; n = 947), yellow-bellied sliders (Trachemys scripta scripta; n = 301), cooters ( Pseudemys spp.; n = 235), common snapping turtles (Chelydra serpentina; n = 165), and eastern painted turtles (Chrysemys picta; n = 93) made up 94.3% of all patients. Patient admissions peaked in May when 25.6% (473/1,847) of all turtles were admitted. Cooters were the most-likely species to be gravid, and the loss of gravid females may put this population at increased risk for decline. The majority of wild turtles presented for anthropogenic causes, primarily vehicular trauma (63.2%; 1,168/1,847), which also had the greatest mortality at 57.8% (675/1,168) of any presenting complaint. Coelomic breach was the presenting injury with greatest risk of dying, increasing the risk of dying by 4.8 times. Other factors that were associated with increased mortality included head injuries, myiasis, and cranial or caudal midline injuries. Of all turtle species, eastern box turtles most commonly presented for nontraumatic conditions including aural abscesses (8.2%; 78/947), upper respiratory infections (6.3%; 60/947), and both conditions concurrently (2.5%; 14/947). While many turtles presented with little to no chance for survival in the wild, 47.6% were eventually released and that number increased to 62.0% released for those that survived 24 hr or longer after presentation. This study adds to the knowledge about the treatment of injured and diseased wild turtles in order to potentially ameliorate the overall impact of humans, especially as a result of vehicular trauma.

CHARACTERIZING THE 25-HYDROXYVITAMIN D STATUS OF TWO POPULATIONS OF FREE-RANGING EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA).

Ultraviolet B radiation is recommended for captive reptiles to stimulate production of adequate levels of vitamin D; however, little is known regarding the vitamin D status in many free-ranging populations. Current reference ranges for vitamin D in eastern box turtles have not yet been established. Sixty free-ranging eastern box turtles (Terrapene carolina carolina) from two well-studied populations in Illinois (n = 24) and Tennessee (n = 36) were assayed for plasma vitamin D concentration in 2014. There were no significant differences in concentrations between individuals in Illinois (mean: 117.5 nM/L) and Tennessee (mean: 98.7 nM/L) (P = 0.129) populations. Similarly, there were no differences in concentrations based on age class (P = 0.533) or sex (P = 0.532). There was a significant correlation between UV at the time of capture and vitamin D concentrations (R = 0.301, P = 0.030). Vitamin D was not correlated with total calcium (R = 0.018, P = 0.89) or Ca : P ratio (R = 0.025, P = 0.85). Diseases in captive individuals, including secondary nutritional hyperparathyroidism, may commonly be associated with vitamin D deficiencies, and clinical intervention relies on reference data. Vitamin D supplementation may be recommended if animals are deemed to be deficient. Data obtained can be used to improve the care of captive and free-ranging turtles by providing reference ranges, as well as better characterize the health of wild populations.

Translocated and Resident Eastern Box Turtles (Terrapene c. carolina) in New York: Movement Patterns and Habitat Use

Translocation of animals to new habitats is a common conservation management strategy but is of uncertain effectiveness. Terrapene c. carolina (Eastern Box Turtle) are often the subject of translocation efforts. To understand the effectiveness of this strategy, we radio-tracked 19 translocated and 7 resident Eastern Box Turtles to assess movement patterns and habitat use, including hibernacula selection. Using data collected over 4 years from a nature reserve in New York, we compared home range, maximum distance traveled, and total distance traveled for both translocated and resident turtles. We found no difference between translocated or resident turtles or between sexes for any of these measures. These results suggest that translocated turtles at this site adapted well to their new habitat.

MULTI-DRUG RESISTANCE PATTERNS OF ENTERIC BACTERIA IN TWO POPULATIONS OF FREE-RANGING EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA).

Gram-negative isolates (n = 84) from 71% of free-ranging Eastern box turtles (Terrapene carolina carolina) in Illinois and Tennessee, United States, demonstrated resistance to at least one antibiotic while 30% of isolates demonstrated resistance to two or more antibiotics. Resistance was observed against cefoxitin, amoxicillin-clavulanic acid, cefazolin, ampicillin, ticarcillin, cefovecin, and ceftiofur. Gram-positive bacteria were isolated from 49 turtles, and all were observed to be resistant to two or more antibiotics. Gram-positive isolate resistance was observed to penicillin, cefoxitin, oxacillin, clindamycin, amikacin, enrofloxacin, cefovecin, ceftiofur, cefazolin, marbofloxacin, gentamicin, erythromycin, trimethoprim-sulfamethoxazole, and chloramphenicol. Health parameters including packed cell volume, total white blood cell count (WBC), total solids (TS), and weight were not significantly different based on antibiotic resistance patterns; however, decreasing WBC and TS were observed when the number of antibiotic-resistant detections in Gram-positive bacteria increased.

Isolation and characterization of antiproliferative peptides from Chinese three-striped box turtle (Cuora trifasciata).

In this study, the whole proteins from a Chinese three-striped box turtle (Cuora trifasciata) were extracted and hydrolyzed using three proteases (alcalase, papain, and protamex). By orthogonal experiments, the optimal hydrolysis conditions for producing peptides with the highest cancer cells growth inhibition activity were determined. Such as, the maximum inhibition on MCF-7 cancer cells (92.37% at 1 mg/mL) was achieved by papain hydrolysis (pH 8, 37 °C, enzyme-to-substrate ratio (E/S) 1.5%), and the maximum inhibition on HepG2 cancer cells (94.16% at 1 mg/mL) was reached by protamex hydrolysis (pH 8, 40 °C, E/S 2%). Using ultrafiltration and Sephadex G-15 column chromatography, two polypeptides M2 and F4 were isolated. At 500 μg/mL, M2 exhibited 74.7% and 62.9% of antiproliferation activities on MCF-7 and HepG2 cancer cells, respectively; and F4 displayed good inhibitory effects on MCF-7 (70.59%) and HepG2 (78.6%) cancer cells. M2 and F4 had lower inhibition (<20%) than drug 5-FU (>60%) on normal liver cells L-O2. Moreover, three peptides, EMLQPPL, PGKPLFL, and SCCSCDED, were identified; their inhibitory effects on cancer cells were confirmed after synthesis. These data, for the first time, demonstrated that Cuora trifasciata-derived proteins could be used for preparing antiproliferation peptides.

A Severe Ranavirus Outbreak in Captive, Wild-Caught Box Turtles.

A Ranavirus outbreak in a captive population of wild-caught individuals was monitored using clinical evaluations and real-time PCR in 317 wild box turtles held in captivity during translocation. During the 2-year study period, the population experienced 71.6% mortality, suggesting that ranaviruses can rapidly attenuate populations. Wide variation in infection rate (7-94% per sampling period) was observed, which may have been driven by clearing and reinfection, adaptive immunity, or imperfect detection using noninvasive samples. Only nasal clinical signs were significantly related to infection status, and agreement among sample types was low. Subsequent to the initial outbreak, low mortality but high real-time PCR prevalence of Ranavirus was observed, suggesting that surviving individuals might be tolerant.

A turtle cognition research demonstration enhances visitor engagement and keeper-animal relationships.

Environmental enrichment techniques present animals with cognitive challenges while providing them opportunities to make choices and exert control over their environment. In this way, cognitive research and training is enriching to animals and can be used as a form of enrichment in zoos and aquariums. Cognitive research demonstrations also provide an opportunity to enhance visitor experience, as well as foster interactions between animals and keepers. We investigated how cognitive research sessions involving eastern box turtles (Terrapene carolina carolina) at Disney's Animal Kingdom® impacted both the rate of visitors coming to the exhibit and the amount of time they spent engaged. Further, we used a questionnaire to assess the impact of keeper participation in these sessions on their relationships with and perceptions of the turtles. While visitation rate to the exhibit was not impacted, cognitive research sessions held visitor attention for longer than keeper interpretation or at times during which no keepers or researchers were present. We also found that keepers that had worked with the turtles for longer and keepers that regularly participated in cognitive research sessions reported stronger bonds with the turtles. Our research suggests that use of cognitive research and training demonstrations for guest viewing in zoos and aquariums may enhance visitor learning opportunities by increasing the amount of time they spend at the exhibit. Our study also provides evidence that participation in such demonstrations by zoo and aquarium professionals can be related to improved keeper-animal bonds, potentially resulting in better husbandry and enhanced animal welfare.

Mass mortality of eastern box turtles with upper respiratory disease following atypical cold weather.

Emerging infectious diseases cause population declines in many ectotherms, with outbreaks frequently punctuated by periods of mass mortality. It remains unclear, however, whether thermoregulation by ectotherms and variation in environmental temperature is associated with mortality risk and disease progression, especially in wild populations. Here, we examined environmental and body temperatures of free-ranging eastern box turtles Terrapene carolina during a mass die-off coincident with upper respiratory disease. We recorded deaths of 17 turtles that showed clinical signs of upper respiratory disease among 76 adult turtles encountered in Berea, Kentucky (USA), in 2014. Of the 17 mortalities, 11 occurred approximately 14 d after mean environmental temperature dropped 2.5 SD below the 3 mo mean. Partial genomic sequencing of the major capsid protein from 1 sick turtle identified a ranavirus isolate similar to frog virus 3. Turtles that lacked clinical signs of disease had significantly higher body temperatures (23°C) than sick turtles (21°C) during the mass mortality, but sick turtles that survived and recovered eventually warmed (measured by temperature loggers). Finally, there was a significant negative effect of daily environmental temperature deviation from the 3 mo mean on survival, suggesting that rapid decreases in environmental temperature were correlated with mortality. Our results point to a potential role for environmental temperature variation and body temperature in disease progression and mortality risk of eastern box turtles affected by upper respiratory disease. Given our findings, it is possible that colder or more variable environmental temperatures and an inability to effectively thermoregulate are associated with poorer disease outcomes in eastern box turtles.

Protection mechanisms of the carapace of a box turtle

In this study we explore the materials design principles of the carapace of a Terrapene Carolina box turtle, which possesses a sandwich-like structure consisting of a foam-like interior layer (FIL) enclosed by two dense exterior layers (DEL). A constitutive scheme accounting for the large deformation, plastic yielding and post-yield strain hardening caused by densification of the cells in the foam is developed to model the mechanical properties of the FIL, and a large deformation elastic-plastic model for the DEL is proposed. Computational simulations of the carapace subjected to indentation loading are performed and it is found that the layer sequence plays an essential role in the mechanical properties of the carapace. For the sandwich-like layering, the stiff DEL provides penetration resistance and the FIL contributes to the energy dissipation of the entire structure through plastic deformation, which enables reduction in back-deformations, enhanced penetration resistance and low stresses transmitted to the inner layer. For other layer sequential patterns, the contributions of the DEL and FIL are limited, leading to poorer mechanical performance. Based on these results, we propose that the sandwich-like structure of the carapace of the box turtle is designed to maintain sufficient resistance to penetration deformation, a defeating mechanism, and at the same time to significantly amplify energy dissipation, a defending mechanism. This double function could be used in the development of future human body armor.

Morbidity and mortality in reptiles presented to a wildlife care facility in Central Illinois

We examined morbidity and mortality of 200 reptiles, representing 13 different species that were presented to the University of Illinois Wildlife Medical Clinic (WMC) from 2003 to 2010. Snapping turtles (Chelydra serpentine; n = 46), box turtles (Terrapene sp.; n = 43), painted turtles (Chrysemys picta; n = 37), and red-eared slider turtles (Trachemys scripta elegans; n = 33) were the most frequently seen species. Turtles were significantly more likely to be presented to the WMC following collision with a motor vehicle (n = 73) than any other reason, including idiopathic trauma (i.e., trauma of unknown origin; n = 25) or infectious disease (n =18). The findings from this cross-sectional study suggest a potential for community education in limiting reptile traumas resulting in presentations to a wildlife hospital.

Thermal consequences of subterranean nesting behavior in a prairie-dwelling turtle, the Ornate Box Turtle (Terrapene ornata)

Many oviparous reptiles deposit eggs in excavated nest chambers, and the location and depth at which eggs are laid can affect predation risk, incubation duration, mortality rates, and hatchling phenotype. Among turtles, nest depth also influences incubation conditions of some large-bodied species, but nest depth is generally expected to vary less among small-bodied species. We monitored nesting behavior of Ornate Box Turtles (Terrapene ornata (Agassiz, 1857)) for two seasons in Illinois. We used direct observations to confirm that, among 31 nesting events, six females oviposited while beneath the substrate surface. Furthermore, comparisons of body length to nest depth indicated that five additional females likely also constructed nests while buried. Nests laid while females were underground were deeper, on average, than other nests (16.7 versus 11.2 cm), and while mean nest temperatures were similar between groups, temperature fluctuations and maximum temperatures were lower among nests that were laid while females were underground. Subterranean oviposition appears to have moderated incubation temperatures by allowing females to deposit eggs at greater depths than would be possible from the surface. This little-documented behavior may be a mechanism for this species to influence the incubation environment, which in turn may influence hatchling phenotypes.

A new eimerian (Apicomplexa: Eimeriidae), from ornate box turtle, Terrapene ornata (Agassiz) (Testudines: Emydidae) from northwest Arkansas, USA.

A new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) collected from an ornate box turtle, Terrapene ornata (Agassiz) from Arkansas, USA, is described. Oöcysts of Eimeria doddi n. sp. are ovoidal to ellipsoidal with a smooth, light to darker brown, bi-layered wall, measure 21.1 × 14.0 µm, and have a length/width (L/W) ratio of 1.5; both micropyle and oöcyst residuum are absent, but a polar granule is present. Sporocysts are ellipsoidal, 9.9 × 6.1 µm, L/W 1.6; the Stieda body is present, but the sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of small granules in a cluster. Sporozoites have a spheroidal anterior refractile body, a subspheroidal posterior refractile body, and one centrally-located nucleus. This is the third description of an eimerian from the turtle genus Terrapene Merrem and the second from T. ornata. In addition, we report Eimeria ornata McAllister & Upton, 1989 from T. ornata from Texas.

PREVALENCE OF TERRAPENE HERPESVIRUS 1 IN FREE-RANGING EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) IN TENNESSEE AND ILLINOIS, USA.

Diseases affecting the upper respiratory tract, such as herpesviruses, are well described in captive chelonians worldwide, but their importance in free-ranging populations is less well known. To characterize the disease epidemiology of terrapene herpesvirus 1 (TerHV1), 409 free-ranging eastern box turtles ( Terrapene carolina carolina) in Tennessee and Illinois, US were tested for TerHV1 in 2013 and 2014 using TaqMan quantitative PCR. Whole blood and swabs of the oral mucosa were collected from 365 adults (154 females, 195 males, 16 unknown sex) and 44 juveniles. The prevalence of detection was 31.3% (n=128). Turtles were more likely to be positive for TerHV1 in July (50%; n=67) compared to September (38%; n=44) and May (11%; n=17). Turtles sampled in 2014 had a significantly higher prevalence (50%; n=98) than in 2013 (14%; n=30). In a multivariate model, only season, year, and the interaction between season and year were maintained; turtles were most likely to be positive in July (odds ratio: 30.5) and September (odds ratio: 41.8) 2014 compared to May 2013. The prevalence was not statistically different by state of collection, sex, or age class. Packed cell volume (25.5%) and total solids (4.8 mg/dL) in positive turtles were significantly higher than in negative turtles (23.0%; 4.3 mg/dL). Positive turtles had increased eosinophil concentrations, fewer lymphocytes, and fewer monocytes. No clinical sign was associated with detection of herpesvirus. Widespread DNA evidence of TerHV1 infection was detected in eastern box turtles, and knowledge of the epidemiology of this virus may aid in management of free-ranging and captive individuals.

Thermal environment and microhabitat of ornate box turtle hibernacula

Box turtle populations are under significant threat from historic and current alterations of land‐use where remaining populations often occur in remnant patches of suitable habitat surrounded by a heterogeneous mixture of anthropogenically altered, unsuitable habitat. Ornate box turtles Terrapene ornata are a prairie‐dependent species, are considered Near Threatened by the International Union for Conservation of Nature (IUCN), and are Endangered or Threatened within many US states. Since their range exists largely in northern latitudes, aspects of hibernacula are particularly important for winter survival. How box turtles select hibernacula within prairies is likely of great importance to better understand which microhabitats are selected for and to identify areas of suitable habitat for management purposes. Using radio telemetry in conjunction with temperature dataloggers (iButtons), we examined the phenology and thermal characteristics of box turtle hibernation, and quantified microhabitat selection of their hibernacula in remnant prairie patches. We monitored hibernation initiation/termination phenology and turtle carapace temperatures, and quantified vegetative and soil microhabitat variables of hibernacula for seven turtles in 2014/2015 and 18 turtles in 2015/2016. Box turtles initiated (descended into hibernacula) and terminated (ascended out of hibernacula) at similar time periods across two years. Although the ambient thermal environment consistently experienced temperatures below freezing, turtle hibernacula offered a buffer against those temperatures and thus the temperature of turtle carapaces never fell below freezing. Turtles selected microhabitat hibernacula with higher percentages of sand, leaf litter and bare ground, and lower percentages of clay, silt, shrubs and herbaceous ground cover. Our study suggests the phenology of box turtle hibernation may be similar across years and that hibernacula selection is driven by above‐ and belowground characteristics that ultimately lead to a more stable and warmer thermal environment.

Spring emergence of Eastern Box Turtles (Terrapene carolina): influences of individual variation and scale of temperature correlates

Many organisms spend considerable time in dormancy to avoid stressful environmental conditions. Understanding the timing and triggers of dormancy behavior is critical for understanding an animal’s life history and behavior. Eastern Box Turtles (Terrapene carolina (L., 1758)) avoid winter temperatures by burrowing into the soil and remaining dormant. Identifying the proximate environmental cues that trigger emergence can improve conservation efforts by reducing potential aboveground turtle mortality. During a 17-year study, half of all variation in emergence timing was attributed to individual variation and the habitat that they occupied during dormancy. We suggest that individual variation in emergence timing is common within populations and confounds efforts to identify reliable emergence cues. Additionally, the scale of meteorological data limits the ability to identify emergence predictors. Using data from temperature loggers placed at dormancy locations, we found that surface air temperatures, averaged over the 5 days prior to emergence, were more strongly related to emergence probability than any variables derived from local weather stations. Turtles generally did not emerge from dormancy until the 5-day mean surface temperatures measured at dormancy sites reached approximately 15 °C. Our results suggest that individuals respond differently to environmental thresholds for emergence and individuals may be characterized as risk-taking or risk-aversive.

Shell shape and genetic variability of Southeast Asian Box Turtles (Cuora amboinensis) from Borneo and Sumatra

Distinguishing between species is an essential aspect of animal research and conservation. For turtles, morphology and genetic analysis are potentially valuable tools for identification. Shell shape is an important component of phenotypic variation in turtles and can be easily described and quantified by geometric morphometrics (GM). Here, we focus on carapace and plastron shape discrimination of immature Southeast Asian box turtles (Cuora amboinensis) from two of the Greater Sunda Islands with partially distinct faunas. GM analysis identified significant differences in carapace and plastron shape between turtles from Borneo and Sumatra. The discrimination success amounted to 90% and 83.7% for carapace and plastron, respectively. The correlations of carapace and plastron shapes were high for Sumatra (0.846), and less pronounced for Borneo (0.560). We detected no differences in the ontogenetic trajectories of the shell shape between the two islands. We conclude that shell shape can be used for reliable geographic assignment of C. amboinensis of unknown origin. In addition to the comparison of shell shapes, turtles from Borneo, Sumatra, Seram, and turtles of unknown origin from two Czech zoos were studied genetically. Analysis of the complete mitochondrial cytochrome b gene confirmed the distinctness of turtles from Borneo and Sumatra, with p-distance 2.68 – 4.09% sequence difference. Moreover, we discovered considerable genetic difference in Seram turtles of previously unknown haplogroup (p-distance 6.00 – 8.68%) revealing the need for the revision of the whole species complex of Cuora amboinensis.