The Coahuila box turtle (Terrapene coahuila) is an endangered species of chelonian endemic to the Cuatro Ciénegas valley in northern Mexico. It is the only aquatic member of the genus Terrapene and is dependent on permanent and seasonal wetlands. Over the past several decades, T. coahuila populations have declined from habitat loss as the wetlands have dried due to human modification of the valley. We conducted a survey of the status of the species from 2011 to 2018, updating previous estimates of population density and overall population size. We also collected data on sex ratio in each of the 8 wetland study areas in the valley and report a strongly male-biased sex ratio. Our results indicate a total population size of approximately 1791 individuals, based on recorded densities from 0.24 to 3.3 individuals/ha among 539.76 ha of suitable habitat in the 8 wetland areas. This estimate is lower than previous studies indicated, implying direct effects of habitat loss on T. coahuila. If habitat loss due to lowering of the water table continues, this species will become extinct. We recommend conservation measures including upgrading the species' International Union for Conservation of Nature Red List status to Critically Endangered, protecting and restoring key wetlands in the valley, and establishing captive assurance colonies in Mexico.

Understanding the interface between spatial and thermal ecology is integral to understanding energy acquisition and the life histories of ectotherms. Snapping turtles (Chelydra serpentina) occupy a wide range of habitats that vary greatly in their thermal properties. We studied activity, movements, and thermoregulation of C. serpentina in a small, land-locked lake in central Michigan, USA, using radiotelemetry. Consistent with our a priori predictions, turtles were active within core areas along the lake's edge, showed both diurnal and nocturnal activity, and did not make extensive interwetland movements. Turtles left the lake only for nesting or to hibernate in Sphagnum peat or in the banks of a nearby stream. Home range and core area size estimates of C. serpentina were small compared with other previously studied populations, perhaps in part because of the small dimensions of our lake. Contrary to our prediction of a broad T_set (thermoregulatory set-point) range for a large-bodied, habitat generalist turtle, we found a comparatively low and narrow laboratory-determined T_set range (22°C–26°C). Turtle body temperatures (T_b) cycled between May and August and attained maximal values during the evening hours, a pattern that likely results from thermal inertia, the selection of aquatic thermal patches, or both, as T_e (operative temperatures) declined. Turtles most effectively maintained T_b within T_set during July and August when thermal conditions were most favorable. Throughout most of the active season the highly aquatic habits of C. serpentina apparently negated the effects of variations in daily weather conditions and their effects on incoming levels of solar radiation on variation in T_b. However, turtles maintained higher average T_b on sunny days compared with overcast days in April and May, the coolest months of the study. Diel T_b cycling ceased during September and October and average T_b declined despite favorable thermal conditions, at least during September, a pattern that could reflect a downward shift in the T_set range. Comparatively, C. serpentina is less effective at thermoregulating than is a small-bodied species at a similar latitude (Chrysemys picta marginata). Apparently, thermal inertia and lack of atmospheric basking proclivities influenced the thermoregulatory precision in our turtles.

The loggerhead musk turtle (Sternotherus minor) and eastern musk turtle (Sternotherus odoratus) are widespread species considered common throughout much of their respective ranges. Florida populations of S. minor and S. odoratus inhabit a variety of habitats, including freshwater springs and spring runs. We sampled populations of S. minor and S. odoratus from May 2000 through July 2015 as part of a long-term freshwater turtle assemblage study in a state-protected spring-run complex in central Florida. For each species, we 1) generated population estimates, 2) quantified survivorship and recruitment, and 3) calculated sex ratios, biomass, and density. Population estimates were 3417 for S. minor and 1977 for S. odoratus. Sex ratios were approximately 1:1 for both species, and density and biomass estimates were higher than most previous studies. Annual apparent survivorship was higher in male S. minor than in females, but the opposite was true for S. odoratus. Lambda values (k) suggest stable to slowly increasing populations for both species. Population growth rates for S. odoratus were equally influenced by both adult female mortality and mortality of first-year turtles, while those for S. minor were influenced by only adult female mortality. The lower fecundity values for S. odoratus may increase the importance of younger age classes in maintaining populations. Healthy populations of common species are important in maintaining overall community functions, as they often provide the base for many ecosystems. Therefore, it is prudent to promote conservation of common species to protect ecosystem structures and services.

The description of Chelodina kuchlingi was based on a single holotype with the type locality Kalumburu in the northern Kimberley, Western Australia. Over the last decade, C. kuchlingi was variously considered a valid species, or its validity was questioned because the accuracy of the type locality was questioned, or it was listed as synonym of Chelodina rugosa. Serum-immunological data published 45 yrs ago, suggesting a sister species status of the then still-undescribed species to C. rugosa, were recently corroborated by mitochondrial DNA technology. Accordingly, in the most recent International Union for Conservation of Nature Draft Red List assessment, C. kuchlingi is considered to represent a valid, Data Deficient species. A review of documents from the 1960s demonstrates that mix-ups of collection data of various turtle specimens occurred between their collection in the Kimberley in 1965 and 1966 and their accession in the Western Australian Museum 9–24 mo later. Three specimens of C. kuchlingi, including the holotype, were evidently collected in 1965 at Parry Creek in the eastern Kimberley. An additional C. kuchlingi specimen was collected at this location in 1974. Turtle surveys in the Kalumburu area since 1974 have not recorded C. kuchlingi. The type locality of Chelodina kuchlingiCann 1997 is corrected accordingly and clarified as Parry Creek, lower Ord River floodplain, Kimberley, Western Australia (ICZN Recommend. 76A.2). The currently known distribution of C. kuchlingi is restricted to this site. Damming of the Ord River in the 1960s and 1970s and large-scale agricultural developments changed the hydrology of the floodplain and established an open channel connectivity close to the Victoria River catchment in the Northern Territory. Turtle collections and surveys in the Parry Creek area during the 21st Century have not detected C. kuchlingi and only recorded Chelodina walloyarrina and C. rugose–like specimens. Chelodina rugosa is widespread in the Northern Territory and Queensland but had never been recorded in the Kimberley prior to 2007. A targeted survey is urgently needed to investigate if a recent invasion by its common and widespread sister species is threatening the persistence of the rare and localized C. kuchlingi.

We compared the spatial biology of Blanding's turtle (Emydoidea blandingii) in typical and highly disturbed habitats in the Weaver Dunes area of Wabasha County, Minnesota. The typical habitat (Old Zumbro River Wetlands) is a large area of riparian forest with open shallow wetlands containing emergent vegetation, whereas the highly disturbed area (Weaver Bottoms) is a large shallow wetland that was previously vegetated but at the time of this study was mostly open water. Between 15 April 1999 and 1 April 2000, we used radiotelemetry to determine the distance and rate of movements of 35 adult turtles (23 females, 12 males). We used ArcView GIS to examine movements, activity areas, and home ranges of 16 females and 8 males with the most complete records. During the activity season, males made more and shorter-distance movements and had more activity areas (mean = 3.13, standard error = 0.40) than did females (mean = 1.75, standard error = 0.19), although females made longer overland movements typically associated with nesting. Mean home range estimates, calculated using the minimum convex polygon, bivariate normal density kernel, and poly-buff methods, averaged 91.59 ha (standard error = 29.95) for males and 46.0 ha (standard error = 7.40) for females. Poly-buff home ranges of adults in Old Zumbro River Wetlands were significantly smaller than in Weaver Bottoms. Average home ranges of adults at Old Zumbro River Wetlands were typical of Blanding's turtles and home ranges reported at other locations across their range, whereas the average home ranges of adults at Weaver Bottoms were approximately 7 times larger than that found in Old Zumbro River Wetlands and larger than reported for any other population of Blanding's turtles. The large home ranges at Weaver Bottoms were associated with expanses of open water and fragmented vegetated areas, which suggests that the maintenance of or even an increase in emergent vegetation in the Weaver Bottoms is important for the long-term stability of the Blanding's turtle population at the Weaver Dunes area.

We compiled observations of 116 nesting events by 37 female Blanding's turtles between 2013 and 2017 for a population located along the western shore of Lake Michigan, USA, to identify triggers of nesting activity. Across years, nesting dates were negatively related to average daily temperature during April and May, such that each degree increase in average temperature during April–May was associated with a 7-d-long shift earlier in nesting (defined as the date by which 90% of females had nested). Within years, nesting was more likely to occur when mean daily temperatures were > 18.9°C, the moon was in its brightest phase, and wind emanated from the east or south. These thresholds may be useful for timing interventions to protect nests and nesting female Blanding's turtles, although they may differ among populations across the species' range.

Environmental conditions during embryonic development affect morphology, behavior, and survival in turtles. Nest temperature also could affect posthatching traits of offspring, such as emergence behaviors. We monitored thermal conditions in painted turtle (Chrysemys picta) nests along the Mississippi River in Illinois to examine their influence on offspring survival and nest emergence. We recorded hourly temperatures within nest cavities during embryonic development in summer 2016 (n = 34) and after hatching through the following January (n = 15–20). Hatching success and posthatching survival appeared to be largely unaffected by thermal conditions recorded in nests. Emergence of neonates from nests was observed from 19 March through 12 May 2017. Onset of offspring emergence occurred later in the spring for nests with greater exposure to subzero temperatures in winter. For nearly all nests with live offspring, siblings did not emerge en masse, but instead departed the nest across multiple days. Nests with higher mean temperatures during incubation exhibited earlier mean emergence dates in spring, yet emergence duration was positively correlated with thermal maxima experienced in nests in fall and winter. Thus, thermal environments in nests at different times of year apparently elicited variation in spring emergence timing of C. picta hatchlings.

The wood turtle (Glyptemys insculpta) is a threatened species that uses agricultural fields, in part, to nest, bask, and feed. This use of anthropogenic habitats has resulted in the injury and death of individuals during crop harvest. Turtles have been exposed to hay harvests for over a century but the increased use of rotary disc mowers may have increased mortality rates to unsustainable levels. Mitigation measures have focused on raising blade height to minimize contact with turtles but these measures are based on the dimensions of the largest turtles and the effects of agricultural machinery on subadults, juveniles, and hatchlings have not been quantified. We sought to quantify how different agricultural machinery affects wood turtles at multiple life stages through experimental trials using 2 mower types. Cantaloupe (Cucumis melo) halves were used as turtle proxies to avoid actual harm to turtles. We found that rotary disc mowers resulted in a significantly greater injury to adult (i.e., female, male, and subadult) and young (i.e., juvenile and hatchling age class) proxies at low grass heights (10–20 cm) compared with sickle cutter bar mowers. Young proxies were found to be essentially unaffected by the sickle mower at all grass heights, but they were highly affected by the rotary disc mower at grass heights from 10 to 18 cm. If blade heights were to be raised to reduce the risk to wood turtles, a minimum blade height of 17 cm would be needed to obtain > 50% of adults remaining undamaged during harvest and a minimum height of 15 cm would be needed for young turtles.

Freshwater turtles from 28 species representing 6 families, categorized as “wild,” “captive,” or “wild-caught, captive-raised,” were analyzed for the presence of intraerythrocytic, parasitic protozoa. Microscopic analyses of blood smears from 327 individual turtles revealed parasites in the blood of 29% of these individuals (n = 96), with levels of parasitemia ranging from 0.003% to 2.1%. SYBR ^® Green–based quantitative polymerase chain reaction confirmed these results with 29% overall prevalence (94 of 324), with 66% prevalence in the Geoemydidae, 26% prevalence in the Emydidae, and 23% prevalence in the Kinosternidae. No infections were detected in members of the Chelidae, Pelomedusidae, and Trionychidae. Prevalence was highest in wild turtles with 67%–100% from 7 locations, followed by wild-caught, captive-raised turtles with 4%–26% from 2 locations, while detections in captive turtles were zero in 2 locations and 3% in the remaining third location. Comparative sequence analyses of 583-bp amplicons of 18S rRNA gene fragments allowed us to identify 80 Haemogregarina infections and one Hemolivia infection. Parasites representing the genus Hepatozoon were not detected. Because parasites were generally detected in wild turtles and only rarely in captive turtles, captive breeding with subsequent release of turtles would seem to pose little risk to free-ranging turtles with regard to the spread of these parasites. On the contrary, wild turtles would be more likely sources of parasite transmission to captive populations if used in breeding programs.

The Internet is being exploited as a medium for illegal wildlife trade, and protected wildlife can now be sold and bought across social media and e-commerce platforms. This article is a 13-mo study on the online trade of Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)–listed chelonians on a localized Hong Kong website. During this period, more than 400 posts were collected, with more than 300 posts selling CITES-listed chelonians. Based on our findings, we give 2 general recommendations in enforcing the online illegal wildlife trade: 1) increase knowledge of CITES regulations on pet trade forums and 2) introduce digital solutions to monitor pet trade forums.

Three sea turtle species (loggerhead [Caretta caretta], green [Chelonia mydas], and hawksbill [Eretmochelys imbricata] turtles) have nesting sites at Ishigakijima Island, which is located in the southwestern part of Japan. This island is known as the geographic southern (low-latitude) limit of north Pacific loggerhead turtles' nesting sites and close to the northern (high-latitude) limit of northwest Pacific green and hawksbill turtles' nesting sites. Our 26-yr nesting survey (1993–2018) revealed that the number of nesting events of loggerhead turtles decreased (with a temporal increment between 2006 and 2008), while the other study reported that the entire Japanese loggerhead nesting population continued to increase substantially from 2006 to, at least, 2012. In contrast, the green turtle population increased gradually, with fluctuations. Hawksbill turtles had several nests annually. The sea surface temperature during the nesting season was significantly related to the annual number of nesting events in loggerhead turtles but not in green and hawksbill turtles. Thus, warming temperature may have caused a reduction in the nesting population of loggerhead turtles at Ishigakijima Island, which is the southern limit of their nesting distribution.

Globally, the hatch success of leatherback sea turtles (Dermochelys coriacea) is much lower than any other sea turtle species. Causes of embryonic mortality, a contributing factor to the low hatch success of the species, are poorly understood. Muscle necrosis, renal mineralization, and bacterial pneumonia are prevalent among embryos and hatchlings in St. Kitts, where hatch success is much lower (<∼ 20%) than the global average (∼ 50%), yet the significance of these conditions in the wider region is unknown. The objective of this study was to describe the pathology of hatchlings and embryos in Grenada as a comparison population for St. Kitts. In 2017, 20 hatchlings, 6 pipped hatchlings, 35 late stage embryos, and 5 early stage embryos were sampled for comprehensive postmortem examination from 12 leatherback nests on Levera Beach, Grenada and 2 nests on St. Kitts. Pathology affected 71% of nests and 44% of individuals from Grenada and 100% of nests and 56% of individuals from St. Kitts. Lesions observed in both populations included skeletal muscle degeneration and necrosis (19%), bronchopneumonia (8%), and renal tubular degeneration (5%) while chorioallantoitis (17%) and mycotic dermatitis (5%) were only observed in Grenada. Gonads were histologically classified as female in all instances (n = 60), suggestive of high incubation temperatures in nests at both locations. Further study is needed to find interventions that reduce the prevalence of perinatal pathology and to identify the basis for the large proportion of eggs that fail to develop as well as embryos that die without significant pathology.

Understanding animals' daily activity patterns such as foraging and resting is key to the effective conservation of individuals, populations, and species. Expanding habitat usage by humans today is likely one of the major factors influencing animal habitat use and behavior. Rapa Nui, a remote Chilean island located at the easternmost corner of the Polynesian Triangle, hosts a population of green turtles, Chelonia mydas, that have been monitored by citizen scientists since 2010. Through the collaborative work of divers from the local community and professional scientists, we describe C. mydas daily underwater resting and foraging patterns in Rapa Nui. We identified 15 individuals by monitoring 19 specific resting locations within the Rapa Nui coral reef. A high level of spatial fidelity for specific resting sites was observed in 12 turtles that used the same location for as long as 5 yrs. Moreover, we observed a clear temporal pattern in the daily use of resting habitats, with 79% of resting activity occurring during low tide. In contrast, the daily peak in feeding activity was associated with high tides. Abiotic characteristics (depth and cardinal orientation) of resting sites did not show significant relationships. The information from this study will inform management of the Rapa Nui Multiple Uses Coastal Marine Protected Area to increase the protection of marine turtles residing at this isolated Pacific Island.

Following a multi-decadal tagging program at loggerhead nesting areas in Greece, 28 individual turtles have been identified with reproductive longevities greater than 21 yrs, ranging from 22 to 33 yrs. Continuation of this long-term tagging program, along with improvement of tag retention through usage of PIT tags, are expected to increase the herein reported maximum reproductive longevity of loggerhead turtles.

Eastern Musk Turtles (Sternotherus odoratus) in a few populations exhibit megacephaly, including those from a population in Arkansas herein described. I initiated a growth experiment in the laboratory with hatchlings from a megacephalic population and those from a nearby normocephalic population in Arkansas, both fed on fish chow for 22 yrs. The experiment, although compromised, suggested that megacephaly in the Eastern Musk Turtle is a plastic, environmental response to diet rather than a genetically based adaptation.

We opportunistically investigated predator visits to enclosed acclimation pens containing juvenile eastern box turtles (Terrapene carolina) over a 34-d acclimation period using motion-triggered cameras. Daily visitation probability by raccoons (Procyon lotor) and fox squirrels (Sciurus niger; the only predator species observed visiting) decreased from a peak of 36% probability of a visit on the first day turtles were penned to nearly zero probability by day 34 (the release day). Our findings indicate predators lose interest in pens over time, and we suggest animals should be released from acclimation pens after predators have lost interest in pens to avoid heightened predation risk of translocated animals.

Studies of mud and musk turtles (family Kinosternidae) are underrepresented in the primary turtle literature, particularly with regard to their population genetics. We have isolated microsatellite loci for Sternotherus carinatus, a first for any species in the family, and tested their ability to cross-amplify in 5 other kinosternids. These loci should provide a useful set of tools for future population genetic studies of kinosternid species.