A detailed understanding of the spatial ecology and habitat requirements of endangered species is critical for population restoration and conservation. Home ranges and movements of the endangered Chinese softshell turtle (Pelodiscus sinensis) were investigated in the Yellow River, northwestern China, from October 2016 to July 2018. We monitored 9 adult turtles (5 females and 4 males) with radio transmitters. Mean linear range size was 440 ± 161 m SD, mean river channel area was 1.98 ± 0.72 ha SD, the average minimum convex polygon was 1.36 ± 0.65 ha SD, average 95% kernel density estimator measured 0.84 ± 0.51 ha SD, with a core area (50% kernel density estimator) of 0.30 ± 0.20 ha SD. Home range values were not significantly different between the sexes nor were they related to straight-line carapace length or mass. Daily movements of P. sinensis averaged 35 ± 18 m SD for males and 43 ± 18 m SD for females, and there was no significant difference between sexes or significant correlation between movement patterns and body size. However, during the nesting season, there was a significant difference between sexes. Turtle activity was highest in May (average daily movement 59 ± 6 m SD) and lowest in January (0.4 ± 0.6 m SD). Given that P. sinensis individuals have small home ranges and are capable of existing in small rivers, management efforts should protect smaller rivers that may be easily overlooked. Results from this study provide the first assessment of home range requirements for P. sinensis, which may be used in future population modeling efforts and are important for establishing conservation strategies for this vulnerable species.

There is limited information on postnesting dispersal of green turtles Chelonia mydas from nesting sites in the Arabian region. Understanding habitat connectivity can promote effective conservation programs across a wider range of critical sea turtle habitats. We present postnesting migration data for 9 green turtles departing from Ras Al Hadd in Oman, one of the largest and most important nesting sites for this species in the northwest Indian Ocean (NWIO). Turtles migrated to Eritrea (n = 1), India (n = 2), Oman (n = 4), and the United Arab Emirates (n = 2), demonstrating connectivity for this species across the NWIO and linkages to known green turtle foraging areas. Turtles used deep international waters of the NWIO, and coastal waters of Eritrea, India, Iran, Oman, Pakistan, Saudi Arabia, and Yemen. Alongside the potential for fisheries bycatch, ghost fishing, entanglement, and direct take in waters near nesting sites and at the dispersal destinations, these movement patterns reveal a need for coordinated efforts to address sea turtle mortality in fisheries at a regional level. These data enhance our knowledge of sea turtle distribution and connectivity in the Arabian region and will contribute to ongoing efforts to conserve sea turtles in the NWIO.

The Central Chiapas Mud Turtle (Kinosternon abaxillare) is one of the least-studied turtles in Mexico. It is considered a microendemic, with a limited distribution in the Central Depression of Chiapas. In this article, we summarize its population ecology and provide a new assessment of its morphology from Villa Hidalgo, Chiapas, Mexico. We captured 168 individuals with 64 recaptures (232 total captures), and we report a population size of 231 individuals with a density of 700 turtles/ha (189 kg/ha standing crop biomass). The population showed a female-biased sex ratio (1:1.5) and the population structure was largely composed of adults. Finally, we provide a set of morphological measurements for all size classes and sexes of K. abaxillare for the first time. The plastral formula (relative lengths of midline plastral seams) was identical in all size classes and sexes (Ab > An > Gu > Hu > Fe > Pe). Females and males reached similar carapace length but not body mass. Further studies are needed to determine the overall conservation status of this range-restricted species.

Turtles have been identified as key dispersers of seeds in many ecosystems; however, seed dispersal by turtles (chelonochory) has received far less attention than seed dispersal by birds or mammals. We assessed the role of gopher tortoises (Gopherus polyphemus)—a keystone species—as potential seed dispersers by analyzing the seed composition of their diet in a globally imperiled ecosystem: the pine rockland ecosystem of South Florida. The pine rocklands contain high numbers of both endemic and invasive plant species that may be dispersed by tortoises. We collected scat samples from wild gopher tortoises living in the pine rockland habitats in the Richmond Tract (Miami-Dade County, Florida, USA) and examined the samples to identify seeds consumed. We extracted 2484 seeds from 53 samples from at least 10 individual tortoises. Of the 2484 individual seeds, we distinguished 33 morphospecies and identified 23 to the species taxonomic level. The 14 most abundant seed species in the scat constituted > 90% of all seeds eaten by the tortoises. Three of the 14 most abundant seeds were from nonnative plants, but none were among the most disruptive invasive species. Tortoises consumed mostly herbaceous ground cover and fibrous grasses. Given that the tortoises were consuming several ground cover plants and contained a high density of those seeds in their scats, they seemed to be consuming the seeds as bycatch rather than selectively feeding on them, therefore supporting Janzen's “foliage is the fruit” hypothesis. The prevalence of many seeds and a variety of seed species in the tortoise scat suggests that gopher tortoises may be serving the ecological role of a seed dispersal agent for some of the plants they consume within the pine rocklands.

Western alligator snapping turtles, Macrochelys temminckii, have experienced population declines throughout most of their distribution. The present study is the first to systematically sample aquatic habitats of western Tennessee to assess the status and distribution of this species within the state. At the 65 sites sampled, we captured 22 individual alligator snapping turtles from 4 sites, including 1 site where juveniles had been reintroduced more than a decade prior. We conclude that M. temminckii occurs at very low densities in western Tennessee, likely due to historical habitat modification (e.g., channelizing rivers or ditching).

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

With 6 subspecies described, the rough-footed mud turtle (Kinosternon hirtipes) has been considered a species with high morphological diversity. One subspecies, K. h. megacephalum, is already extinct. The remaining subspecies are poorly studied, with very limited information available only for K. h. murrayi (a widespread subspecies). The remaining taxa (K. h. tarascense, K. h. chapalense, K. h. magdalense, and K. h. hirtipes) are microendemic and restricted to endorheic valleys in the Mexican Transvolcanic Belt. Using baited fyke nets, hoop traps, and a seine, we surveyed for these microendemic subspecies for 3 yrs across their known distributions. With the data gathered in the field and published information, we conducted a population viability analysis (PVA) to model the minimum characteristics needed to improve population growth under 3 scenarios (optimistic, intermediate, and pessimistic). Very few K. hirtipes turtles were collected. No K. h. chapalense were located in Lake Chapala, but we did capture 4 individuals in Lake Zapotlan. Similarly, only 6 individuals of K. h. magdalense were captured. No K. h. hirtipes individuals were collected in the Valley of México. Two populations of K. h. tarascense were located in the Pátzcuaro basin: the first populations reported for that subspecies. The PVA showed that harvest on adults in populations with fewer than 200 turtles significantly compromises population persistence. However, a population size of 200 and limited or no harvest are enough to increase population size and persistence for at least 100 yrs. Assurance colonies and head-starting may be the only chance for long-term survival of some of these microendemic turtle lineages.

The nest environment plays an important role in influencing sea turtle hatchling phenotype. Increasing global temperatures can potentially cause detrimental changes to hatchling size and performance and ultimately influence their recruitment into the adult population. The mass nesting rookeries of olive ridleys in Odisha on the east coast of India are among the largest globally and the only major ones outside Central America. Many nests laid on the east coast of India are translocated to hatcheries as part of hatchery management practices. Therefore, it is imperative to understand the effects of temperature on hatchlings produced in hatcheries as well as site-specific factors in order to undertake appropriate climate-resilient hatchery management measures. This study examined the effect of temperature on the morphology and locomotor performance of hatchlings produced in 2 different hatcheries on the east coast: in Rushikulya, Odisha, and in Chennai, Tamil Nadu, India. We examined various size (body, flipper, and neck length) and performance (crawl speed, righting ability, and righting propensity) parameters for hatchlings at both hatcheries across a range of temperatures. We found that hatchling size and performance were significantly influenced by nest incubation temperature. Higher incubation temperatures resulted in smaller hatchling size, which in turn was correlated with lower performance variables. Incubation temperature also had a direct effect on hatchling performance independent of hatchling size. The effect of nest temperature on morphology and performance of hatchlings could influence their survival and recruitment rates, thus influencing population dynamics and resilience to climate change.

Incubation temperature is a factor that can affect several traits in turtles such as body size, growth, shape, and sex in species with temperature-dependent sex determination. A clear understanding of these effects is particularly important in threatened species such as the red-footed tortoise (Chelonoidis carbonarius), classified in Colombia as Vulnerable mainly due to the capture of wild individuals to be kept as pets. A previous study on the effect of incubation temperature on sex determination concluded that constant temperatures of 31°C and 33°C are lethal to C. carbonarius embryos and that a temperature of 29°C produces 100% females. Although this showed that C. carbonarius has a temperature-based sex determination mechanism, its full reaction norm is still unknown. To fill in the gaps, we incubated 160 eggs from 47 nests at constant temperatures of 24°C, 26°C, and 28°C. The hatching success rates were 55%, 53%, and 60%, respectively, with extremely long incubation periods of 213, 164, and 138 d. Of the 75 neonates obtained, 58 reached 8 mo of age, at which time 45% (n = 26) were sexed. The sexual proportions (% males) obtained were 88.9%, 60%, and 0% from the 24°C, 26°C, and 28°C treatments. From the calculated thermal reaction norm, we estimated that the pivotal temperature is 26.05°C (95% CI = 25.31–26.69) and the transitional temperature range is from 24.34°C to 27.77°C. Incubation temperature also affected incubation period and hatchling body size and growth. Additionally, we found a significant effect of female body size and mass on egg size and mass, supporting a fecundity selection hypothesis of body size. Finally, we inspected hatchlings for sexual shape dimorphism using geometric morphometrics. We found significant differences in anal notch and plastron shape at 7 d of age, but only differences for anal notch at 1 and 2 mo of age. However, the statistical signal was weak and the results varied with age; thus this sexing technique was unreliable. Given the low critical thermal maxima for embryo survivorship (31°C or less), together with a 100% feminizing temperature of 27.9°C, global climate change coupled with deforestation constitute imminent threats to this species due to demographic impacts such as low recruitment rates and skewed primary sex ratios.

The Sierra Box Turtle, Terrapene nelsoni, comprises 2 recognized subspecies that are distributed across the Sierra Madre Occidental mountain chain in western Mexico and little is known about their natural history. We present new information on the natural history of Terrapene nelsoni klauberi. Our study area was the Monte Mojino reserve located within the larger Sierra de Alamos–Río Cuchujaqui federal protected area in southeastern Sonora. We located 49 individuals in 3 different vegetation types: 4 were found at 600 m above sea level (masl) in the tropical dry forest, 4 at 1000 masl in grassy oak (Quercus spp.) savannah, and 41 at 1300 masl in pine(Pinus spp.)–oak forest. Seven turtles were monitored using radiotelemetry and have the average home range size of 1.7 ha. The areas we sampled appear to consist of mainly adults and the sex ratio is female-biased (1♂:1.5♀). Cloacal temperatures of active turtles and their immediate surroundings suggest that T. n. klauberi actively maintain their body temperature above the surrounding temperatures. Males also have higher average body temperatures than females (29.58°C ± 2.26°C vs. 27.35°C ± 2.71°C). We found no significant patterns of sexual dimorphism in carapace length (i.e., sexual size dimorphism) but did find sexual dimorphism in head size. We also found that 44% of males and 22% of females had severe damage to their marginal scutes, possibly from a local predator or from enduring bites over time from other turtles. Lastly, we observed T. n. klauberi foraging on beetles, mushrooms, grass, and wildflowers. These findings provide a first insight into the natural history of T. n. klauberi and how this species is distributed across different elevations and vegetation types. This information provides a starting point to assess the conservation status of this species. However, this species remains unstudied throughout the rest of its geographic range.

The northeastern extreme of the Mojave desert tortoise (Gopherus agassizii) distribution near Zion National Park in Utah is contested as a natural range limit because of its suboptimal habitat and known anthropogenic movements of tortoises. In this study, we added microsatellite data from nine tortoises from the Zion area to a previously published population genetic analysis to determine the tortoises' likely origins. Our results suggest that both anthropogenic tortoise movements and descendants of local tortoises make up the individuals found near Zion.

The Vallarta Mud Turtle (Kinosternon vogti) was recently described based solely on morphological characters; therefore, an examination of molecular data to determine the validity of this species is warranted. Here, mtDNA barcodes, phylogenetic trees, and three Operational Taxonomic Unit (OTU) analyses offer new evidence to support K. vogti as a distinct lineage within the Kinosternon complex. We generated 1,237 base pairs of the mitochondrial cytochrome oxidase I and cytochrome b genes from two paratype specimens collected at the species' type locality in Puerto Vallarta, Jalisco, Mexico, and compared them with 20 other sequences from BLAST belonging to close relatives representing 16 species. From these sequence data, we estimated genetic p-distances, reconstructed phylogenetic relationships among taxa, and performed 3 different operational taxonomic unit analyses (CD-HIT-EST DNA, ABGD, and Bayesian Poisson Tree Processes). The mean genetic p-distances over all sequence pairs was 0.083 ± 0.00 substitutions per site, with the average number of base pair differences per site between K. vogti and all remaining sequences being 0.083 ± 0.009. The closest species to K. vogti were K. hirtipes (p-distances 0.057 ± 0.00) and K. scorpioides (p-distances 0.058 ± 0.00). Phylogenetic trees from maximum likelihood and Bayesian analyses of the concatenated data set showed the same topology with generally high node support. The 3 operational taxonomic unit analyses identified K. vogti as a distinct OTU and likely a distinct evolutionary lineage.

From 2000 to 2002, the reproductive ecology of the endangered Hainan four eye-spotted turtle (Sacalia insulensis) was studied on Hainan Island, China. A total of 147 adult females were captured, and their reproductive status was evaluated by palpation, X-ray imaging, and ultrasound. Twenty-two gravid females were under observation when they laid their eggs. We observed gravid females and nesting behavior along stream banks between December and April. Nest dimensions ranged from 5 to 6 cm in diameter and from 2 to 3 cm in depth. No females in our study produced more than 1 clutch per season. Clutch size average was 1.9 eggs (range = 1–3 eggs, SD = 0.56, n = 22) with an average egg mass of 16.05 g (range = 11.8–21.0 g, SD = 2.417, n = 21), an average egg width of 2.36 cm (range = 2.1–2.7 cm, SD = 0.135, n = 21), and an average length of 4.65 cm (range = 3.9–5.3 cm, SD = 0.400, n = 21). Hatching success rate was 53%, and hatchlings emerged after an average of 120.9 d (range = 98–148 d, SD = 14.94, n = 21) in late June to early July. The mean nesting site ground temperature was 24.43°C (range = 15.0°C–30.2°C, SD = 2.712, n = 7).

The matamatas (Chelus fimbriata and the recently described Chelus orinocensis) are the largest species in the family Chelidae, easily identified by their distinct morphological characteristics. The matamatas have a wide distribution in South America, occurring in Bolivia, Brazil, Colombia, Ecuador, Guyana, French Guiana, Peru, and Venezuela, as well as Trinidad and Tobago. However, there are many gaps in the knowledge of its distribution. The objective of this study was to present new records of occurrence for the C. fimbriata species complex and describe the area of distribution. We compiled data from published papers, databases in museums and other scientific collections, and research institutes and conservation organizations. From these data we mapped the species distribution, considering 3 types of river drainages based on water color in the Amazon Basin. We added 182 new records in Brazil, Venezuela, Colombia, Bolivia, and Peru, demonstrating that the C. fimbriata species complex has a wide distribution, totaling 6,907,551 km² across all 3 river types. Most records were concentrated in areas lower than 200 m above sea level.

In natural wildlife populations, parasite–host interactions are common ecological phenomena that can be important to community structure. We assessed the prevalence of tick infestation on pancake tortoises, Malacochersus tornieri, with respect to location (inside vs. outside Tarangire National Park [TNP]), tortoise age class, sex, season, site of attachment, and body condition index (BCI). Malacochersus tornieri hosted Amblyomma nuttalli, the tick that also parasitizes other sub-Saharan tortoises of the family Testudinidae. Using a generalized linear mixed model, we found tick infestation to be lower inside TNP than sites set outside TNP. Further, tick prevalence was positively correlated with carapace length and negatively so with BCI. Although observation of ticks siphoning M. tornieri from the carapace was infrequent, the observed rate was, nevertheless, higher than reported from other terrestrial tortoises in sub-Saharan Africa. These results are discussed.

We review the historical and current distribution for Cantor's giant softshell turtle (Pelochelys cantorii) in India. We report 13 new records from Kerala State. Based on our intensive survey in Kasaragod District, we report a potential breeding population from this region.

Successful restoration of Geochelone platynota to Dry Zone ecosystems in Myanmar depends on the survival of translocated tortoises and, therefore, a knowledge of predators and predation is important. We here report the loss of 28 and approximately 200 translocated G. platynota to Eurasian golden jackals (Canis aureus) and wild pigs (Sus scrofa), respectively, at Shwe Settaw Wildlife Sanctuary in central Myanmar. Measures to reduce the risk of future predation include structural reinforcement of acclimation pens to deter wild pigs and the experimental use of large cat (e.g., tiger [Panthera tigris] and leopard [Panthera pardus]) odors to repel jackals and wild pigs from the translocation area.

We conducted population surveys of freshwater turtles in Diaoluoshan National Nature Reserve, Hainan Province, China, from 2012 to 2019, capturing 20 individuals belonging to 4 species, including 2 native species (big-headed turtle [Platysternon megacephalum] and Hainan four-eyed turtle [Sacalia insulensis]) and 2 alien species (red-eared slider [Trachemys scriptia elegans] and common snapping turtle [Chelydra serpentia]). We captured 12 big-headed turtles and estimated their population density (1.6514 individuals/km) and abundance (14 individuals), both of which indicate that Diaoluoshan National Nature Reserve is an important area for turtle conservation, especially for big-headed turtles.

A review of laboratory and field data, together with recent growth experiments, show that Chelydra serpentina, the common snapping turtle, is unable to hypoosmoregulate in salinities more concentrated than their internal osmotic concentration, about one third that of seawater (100% seawater is defined as 35 parts per thousand = 1000 milliosmoles). Circumstantial evidence suggests an understanding of the nascent stages of adaptation of freshwater vertebrates to high salinity habitats should include incidental immune system effects. Recent advances in the study of autoimmunity and ecoimmunology indicate the immune system of vertebrates plays an integrative role in maintaining homeostasis in the face of changing internal and external stimuli and may clarify why a small percentage of snapping turtle hatchlings can grow at relatively high salinities, at least up to 40% seawater.