The Mermentau River drainage in Louisiana has been largely ignored by turtle biologists, despite historical records of its turtle species. In particular, almost nothing is known about the range and abundance of the Sabine map turtle (Graptemys sabinensis) in the Mermentau drainage, which is frequently omitted from descriptions of the species' range. Four specimens of G. sabinensis were collected from the upper Mermentau in 1893 and 1894, but no trapping of the species has been conducted in the drainage since. We determined basking density and relative abundance among basking turtles for Sabine map turtles in the Mermentau drainage, including the Mermentau, Lake Arthur, and 5 major tributaries. We recorded turtles seen during boat surveys and in point-counts from bridges and other access points. The Mermentau and Bayou Plaquemine Brule had the highest basking densities, ranging from 14.0 to 34.5 G. sabinensis per river kilometer. Bayous des Cannes and Nezpique and Lake Arthur had intermediate average densities of 5.0–9.7 G. sabinensis per river kilometer and the river below Lake Arthur and the southern tributaries, Bayou Queue de Tortue and Lacassine Bayou, had the lowest average basking densities, ranging from 0.7 to 1.4 G. sabinensis per river kilometer. Sabine map turtles were the most abundant basking turtle on the Mermentau drainage, accounting for 73% of all turtles seen. Graptemys pseudogeographica, the false map turtle, accounted for only 0.2% of all turtles observed and is approaching extirpation in the drainage, likely due to the near total eradication of mussels that has resulted from extensive dredging of the Mermentau and its major tributary bayous.

Age estimation is important for management of turtle populations, but techniques such as growth ring counts or skeletochronology may be unreliable or impossible to perform. An alternative is to estimate age from growth models using Bayesian inference. However, individual variation in growth parameters needs to be incorporated into these models for them to generate realistic prediction intervals. For long-lived ectotherms such as chelonians, it is also important that models allow for changes in growth at sexual maturity, and that the growth models are combined with prior distributions reflecting realistic age structures. We describe how a hierarchical biphasic growth model fitted to a long-term data set of carapace length measurements for North American snapping turtles was combined with prior age distributions generated from survival estimates for the same population. The model was used to generate individual posterior age distributions for turtles captured on 2 or more occasions, and also for hypothetical turtles of any length that were measured only once. Posterior age distributions for hypothetical turtles were uncertain at any size due to individual variation in growth parameters, supporting the belief of many herpetologists that size is weakly related to age. Age estimates for adult turtles were also sensitive to the prior used. Using the most realistic prior, the 95% prediction intervals for large hypothetical turtles (38-cm male or 31-cm female) ranged from about 25 to 170 yrs with a median of about 70 yrs. Posterior age distributions for turtles first measured as juveniles (< 24 cm) were insensitive to the prior, and estimation precision was improved by individual growth information obtained from recaptures. For example, the 95% prediction interval for a hypothetical 10-cm turtle ranged from 2 to 14 yrs using the most realistic prior, whereas the ages of small (< 24 cm) turtles that were recaptured at least once could usually be estimated to within 1–3 yrs. Similar models could be applied to any data set where measurements and survival data are collected from a large sample of marked individuals, and could potentially be extended to incorporate data on other age indicators. This methodology allows us to produce age estimates that can be applied to management and advocacy of turtle populations while accounting for the inherent uncertainty involved.

Records of turtle remains from Pleistocene deposits in western North America are scarce, suggesting that turtles were uncommon in western landscapes throughout the Pleistocene. However, low numbers of fossils do not necessarily correlate with rarity in the past because taphonomic bias can have a marked impact on shaping what is preserved in the fossil record. We compiled minimum species richness data for 8 geographic regions by depositional setting (caves and open-air sites) and used a 2-factor analysis of variance to examine the effects of geographic region and depositional setting on turtle species richness. We did not find a statistically significant effect of depositional setting on turtle richness, suggesting that the paucity of turtles in the Pleistocene of western North America does not result from that particular form of taphonomic bias. Also, we found a strong regional variation in turtle richness that was dependent on time interval, suggesting a potential shift in regional patterns of richness since the Pleistocene.

Considered a keystone species in the southeastern US coastal plain, gopher tortoises occupy a variety of upland habitat types. Although upland pine-dominated habitats have received much attention, few studies have examined tortoises in nearby coastal beach dune habitats. To examine the distribution and abundance of gopher tortoises in northeast Florida coastal habitats, comprehensive burrow surveys were conducted 3 times during the last 8 yrs on 2 separate gopher tortoise populations near St. Augustine, Florida. The objectives for these surveys were to 1) examine changes in population size and structure in representative upland and coastal dune habitats and 2) describe the response of gopher tortoises to land management practices (i.e., prescribed fire). Total burrow density within the upland population remained stable over the 3 surveys (0.68 burrows/ha in 2005, 0.66 burrows/ha in 2007, and 0.64 burrows/ha in 2011). Burrow densities in the burned areas of the upland habitat increased in areas that were burned at least once since the time of the first survey in 2005 but decreased in areas that were infrequently burned or remained unburned. Burrow density on the beach dunes, however, greatly increased between the most recent 2 surveys (3.63 burrows/ha in 2007 and 8.95 burrows/ha in 2011), possibly attributable to an increased use of a relatively confined habitat, or sampling biases by surveyors. Three different correction factor methods were used to determine gopher tortoise population estimates for each of the surveys, providing a range of estimates. The results of this study and the few others focused on coastal beach dunes suggest that this vulnerable, yet important, habitat should receive more attention because some of the highest gopher tortoise burrow densities have been observed there.

Mojave desert tortoises (Gopherus agassizii) have been translocated for decades, and research-oriented translocations recently have been recommended as a tool to help recover this threatened species. However, avoiding negative genetic impacts from wildlife translocations has been widely cautioned. Populations of the Mojave desert tortoise within a 200–276-km straight-line radius of each other (249–308 km measured around topographic barriers) tend to be genetically correlated and may be considered single genetic units for management purposes. When planning translocations among wild populations, releasing tortoises at recipient sites within a straight-line distance of 200 km from the source population would most conservatively maintain historic genetic population structure. However, the risk of causing outbreeding depression by inadvertently translocating Mojave desert tortoises between more distant populations or those of unknown provenance is low.

The coastline of Rio Grande do Sul State is classified as an area of extreme biological importance for sea turtles and serves as an important feeding and development site. From October 2007 to December 2010 we conducted 36 surveys, covering 4320 km of beach, in which we documented 640 dead sea turtles. The species registered included Loggerhead (Caretta caretta) (n  =  284), Green (Chelonia mydas) (n  =  278), and Leatherback (Dermochelys coriacea) (n  =  27) sea turtles, along with 51 unidentified individuals. Of the stranded turtles, 84.2% were found during spring and summer. An increase in the number of stranded sea turtles over the years (1992–2010) indicates interactions between sea turtles and human activities and a consequent decline in species' populations.

El litoral de Rio Grande del Sur es clasificado como un área de extrema importancia biológica para las tortugas marinas, porque representa un importante sitio de alimentación y desarrollo. Durante el periodo de octubre de 2007 a diciembre de 2010 fueron realizados 36 levantamientos en una extensión de 4.320 km de playa recorrida, donde fueron registradas 640 tortugas marinas muertas. Las especies registradas fueron tortuga cabezuda (Caretta caretta) (n = 284), tortuga verde (Chelonia mydas) (n = 278) y tortuga laúd (Dermochelys coriacea) (n = 27), 51 individuos no fueron identificados. Del total de individuos encallados, 84.2% fueron registrados en los meses de primavera y verano. A través de la tendencia temporal de varamientos de tortugas marinas (1992–2010), se observa un aumento de este número a lo largo de la región costera de Rio Grande do Sul, indicando la ocurrencia de mas interacciones antrópicas y por consiguiente un declinio poblacional de las espécies.

Microorganisms associated with olive ridley and East Pacific green turtle nesting and potential cloacal fluid antimicrobial properties were studied in Guanacaste, Costa Rica. During the 2010–2011 season, bacteria and fungi were isolated from olive ridley cloacal fluid, nest chamber sand, and egg samples. Because of the lack of cloacal fluid bacteria isolated, the focus of the 2011–2012 season shifted to determine whether fluid contained antibacterial properties by using Kirby–Bauer disk diffusion assays, and cloacal fluid and sand samples were taken to see whether bacteria were unique to cloacal fluid. Assays were performed on 34 olive ridley and 5 East Pacific green cloacal fluid samples, yielding no zones of inhibition. In the second season, Corynebacterium sp., Bacillus sp., Klebsiella sp., as well as genera documented in previous studies, were found unique to cloacal fluid. Citrobacter freundii and Serratia odorifera are potential contaminates and were common in cloacal fluid and nest chamber sand samples on all beaches. Fungi unique to cloacal fluid included Fusarium sp. and Geotrichum sp., with no previous record of Geotrichum sp. associated with sea turtle nesting. Our results suggest antimicrobial properties either are absent or undetectable by these methods. Future studies should use molecular techniques for bacterial analysis and alternative approaches for detecting antimicrobial properties.

Gathering natural history information on a species is a necessary first step in understanding its ecology, which can lead to hypothesis generation and the data necessary for its conservation. I studied desert box turtles (Terrapene ornata luteola) at the Sevilleta National Wildlife Refuge in central New Mexico at the northern periphery of this subspecies in the Chihuahuan Desert. I recorded locations and marked all box turtles found in the northeastern part of the refuge over 23 yrs during trips to the site in 1986–1989, 1998, and 2008. I found that desert box turtles at the site sometimes were active in May and early June, but were most active in late June or early July into early October, with greatest activity in July and August. Numbers of box turtles on roads were significantly correlated with air temperature but not precipitation. Daily activity was bimodal during peak activity months. Growth was fairly rapid until about 10 yrs of age and then leveled off dramatically. The largest adults were about 125–130 mm carapace length (CL), and females were significantly longer than males in 2 of 3 survey periods. By 2008, I found a number of adults that were 30–40 yrs old, and several might have been older than 40 yrs. The mean number of eggs in a clutch varied from 2.67 to 3.55, there was no indication of multiple clutches being produced, and variation in egg number was only weakly explained by the CL of the female. Despite low reproductive rates, the population on the Sevilleta has persisted and likely will do well into the future in this protected reserve.

Copulation in South Dakota ornate box turtles (Terrapene ornata) was observed from April through September, with oviposition of 2–5 (x¯  =  4.3) eggs in June. Growth was rapid during the first few years of life but slowed thereafter, with adult females attaining significantly larger (p < 0.001) carapace (x¯  =  117.8 mm) and plastron (x¯  =  123.9 mm) lengths (CL and PL, respectively) than did adult males (x¯ CL  =  114.5 mm, x¯ PL  =  118.1 mm). Both sexes can mature by age nine, with our smallest adult female (CL  =  112.1 mm, PL  =  115.5 mm) larger than our smallest adult male (CL  =  107.9 mm, PL  =  110.4 mm).

The aim of any reintroduction program is to create a viable population that is self-sustaining in the long term. Thus, in the short term, it is important to evaluate the acclimation of reintroduced individuals in order to assess the potential success of the project. In this study, we radio-tracked 30 European pond turtles (Emys orbicularis) reintroduced in the Estagnol Nature Reserve (southern France) in 2008 and 2009. We analyzed each individual's dispersal over the site, its home range, and its pattern of displacement for 2 yrs after its release. About 80% of the released animals were still detected on the site 8 mo after the release operation. Home-range size was highly variable among individuals but was typical of what is known for the species. Home ranges were, however, larger in the first year after release than in the following year, probably because individuals explored the site immediately after release. The released individuals exhibited a typical displacement pattern over the first year, with a larger displacement during spring and summer that was earlier for males (April–May) than for females (June–September). All of these results strongly indicate the success of the acclimation phase of the reintroduction operation. To evaluate the success of reintroduction programs of long-lived species, we recommend, in addition to a long-term demographic study, a fine-scale study of space-use modalities, which allows the assessment of the acclimation phase of the individuals at the new site in the short term. In this way, a rapid reevaluation of the project can be made if failure at this stage is identified, allowing appropriate management actions to be taken at the site.

Hydromedusa maximiliani is a freshwater turtle endemic to the mountainous regions of the Brazilian Atlantic rainforest. Using X-rays techniques, we provide the first substantial records of the species' reproductive biology in the wild. Twenty-six of 42 X-rayed females from 2007 to 2009 were ovigerous between September and December and 9 had eggs each year during the 3-yr period. Clutch size varied from 1 to 3, with 55% of females having 2 eggs. The smallest reproductive female was 100.2 mm in plastron length, corresponding to an age of about 13 yrs old. Significant positive correlation was verified between female body size and both egg size and clutch volume. Nesting was inferred to occur from late spring to early summer (November and December). These findings are important for management programs since this vulnerable species inhabits a threatened biodiversity hotspot.

We studied the population structure, sex ratio, and abundance of a locally endangered species of freshwater turtle, the red-headed river turtle (Podocnemis erythrocephala), in the Unini River in Negro River Basin in Brazil with capture–recapture of marked individuals in 1 yr, including both dry and rainy seasons. We used trammel nets of 3 different inner mesh sizes in the lakes. The nets were revisited at 3-hr intervals from 0600 to 1800 hrs each day. All turtles were released after being marked, measured, and sexed. During the study, 352 individuals were marked including 162 males, 150 females, and 40 immatures. The majority of the turtles (79%) were captured in the dry season when the water level of the river was declining. Mean ± standard deviation straight-line carapace length was 210 ± 14 mm (range 163–262 mm) for males and 251 ± 18 mm (221–303) for females. Most turtles captured were in the intermediate size classes: 200–210 mm for males and 230–270 mm for females. The sex ratio of adults in this population was 1.05 males per female, not significantly different from 1∶1. Only 12 turtles were recaptured, each once: 5 males, 5 females, and 2 immatures. The population showed recruitment and the adults are in equilibrium; however, few turtles were captured in the smallest or largest size classes.

Health evaluations were conducted in 2 captive colonies of Central American river turtles, Dermatemys mawii, from sites in Tabasco, Mexico: Government of the State of Tabasco's turtle farm (GOV) and Arroyo Tabasquillo turtle farm (TAB). Health assessments were conducted in February, May, and August. Each assessment included a group clinical history, physical examinations, serum biochemistry panels, and bacteriological analyses. Additionally, water quality of turtle ponds was analyzed monthly at each site. High frequency of shell lesions and other clinical signs related to a harmful aquatic environment were found at both farms. Serum biochemistry results include levels of urea in both farms that repeatedly exceeded reference values for this species and values greater than normal for total protein, uric acid, and triglycerides at TAB. Bacteriological results showed potentially pathogenic microorganisms in lesions, including Staphylococcus aureus, Escherichia coli, Proteus vulgaris, Serratia spp., Klebsiella spp., and Candida spp. Water quality in both farms was poor; water at TAB presented the worse quality due to its high levels of total ammonia nitrogen (median 1.092 mg/l), nitrite (median 0.011 mg/l), fecal coliform (median 4600 MPN/100 ml), and water transparence (median 0.05 m) and low level of dissolved oxygen (median 0.6 mg/l). In general, the health of captive turtles was compromised at both farms, the most likely factors being inadequate water management, overcrowding, and dietary problems.

There are only a few studies documenting acoustic communication in chelonians; here we provide additional evidence that sound plays an important role in the interchange of information in this group. We recorded 12 nests of Dermochelys coriacea during March 2012 at Barra de la Cruz Beach, Oaxaca, Mexico. Four types of sounds were identified from recordings of nests after 51 d of incubation; our results reinforce the idea that sounds are important to coordinate group behavior in turtles.

Little is known regarding the activity of desert tortoises during winter, especially for the Sonoran Desert Tortoise (Gopherus morafkai). We observed adult, juvenile, and hatchling G. morafkai active during November, December, January, and February at 3 field sites in upland Sonoran Desert in central Arizona. At 1 site all individuals under observation (n  =  36), including males, females, and hatchlings, emerged from hibernacula to drink during the first heavy (> 20 mm) rainfall event (December); at all 3 sites, females were observed active (basking, foraging) during winter much more frequently than were males.

Diamondback terrapin (Malaclemys terrapin) population dynamics in North Inlet–Winyah Bay, South Carolina, a relatively undeveloped salt marsh estuary, were determined from 6 yrs of mark–recapture data. Total terrapin abundance in 4 adjacent creeks was estimated annually at 260–360 terrapins (144–200 terrapins/km) and the mean annual survival probability for terrapins was 0.78. This study in a protected terrapin habitat will provide data for population models and comparisons with threatened populations.

Between 1975 and 2004 the giant South American river turtle (Podocnemis expansa) as well as Podocnemis unifilis and Podocnemis sextuberculata had part of their nesting beaches protected. This resulted in the release of approximately 46 million hatchlings and the apparent recovery of these species in some areas; however, this ranching program faces operational and bureaucratic difficulties. In addition, harvesting wild populations is banned by Brazilian law, thereby excluding local villagers from using this natural resource.