We estimated population sizes, densities, structure, and the sex ratio of a locally endangered species of mud turtle, Kinosternon scorpioides albogulare, on the Caribbean island of San Andrés, Colombia. We estimated the population size at 4343 turtles on the island in 2002, inhabiting both freshwater ponds and mangroves. Densities for the main populations varied from 77 to 254 turtles/ha. The population structure showed that most of the individuals belong to intermediate size classes (110- to 140-mm carapace length) and a few belong to the smaller or larger size classes (< 110- or > 140-mm carapace length). The sex ratio was significantly different from 1:1 and was skewed toward females, 1 male per 1.97 females. No common use was found for the species among native islanders, although people from the continent living on the island use it for diverse purposes. Some threats were identified, such as mangrove pollution and the presence of the introduced species Tupinambis teguixin.

We obtained demographic data on more than 60 gopher tortoise (Gopherus polyphemus) populations in Florida before the emergence of upper respiratory tract disease (URTD). We later resurveyed 10 populations to compare demographic profiles at sites where antibodies to Mycoplasma agassizii were detected subsequently and at sites where they were not. We screened for antibodies and checked for potential biases in studying URTD by determining whether individuals caught above ground were representative of a population as a whole and whether the probability of detection of seropositive (plus serologically suspect) individuals is a function of sample size. Some sites with no indication of decline had relatively high percentages of seropositive individuals, and some sites exhibiting substantial population decline had no or low percentages of seropositive individuals; therefore, our results do not unambiguously implicate the presence of URTD in the population declines. Seropositive individuals occurred at 4 sites not known previously to have them; therefore, our results indicate that exposure to Mycoplasma agassizii has been more widespread than heretofore suspected. The percentage of individuals determined to be seropositive (plus suspect) tends to be related positively to number of individuals tested and the sizes of individuals caught above ground were not always expected from the size distribution of a population; therefore, our results indicate that sampling method can influence the estimate of percentage of seropositive individuals in the population. We suggest that the simplistic conservation response that we have taken to the emergence of URTD may need to be reconsidered and that maintaining or creating conditions necessary to minimize the chance of re-emergence of URTD, to prevent URTD from reaching epidemic proportions, and to allow populations to recover from URTD is important.

The ability of hatchling and juvenile turtles to thermoregulate, as evidenced by selection of preferred temperatures in thermal gradients, is an important factor influencing fitness. Previous studies in laboratory thermal gradients suggest that most young turtles select warm temperatures (25°–33°C) within a narrow range. Confounding factors affecting microhabitat selection, such as predator avoidance, foraging, or social interaction, may influence thermal preference in some species, particularly softshell turtles (Apalone spp.) that frequently bury in the substrate to remain cryptic. We analyzed temperature selection of juvenile Apalone spinifera in an aquatic thermal gradient of 15°–30°C with either gravel, sand, or a combination of sand and no substrate. Across all substrate treatments in the gradient tests, hatchlings selected the warmest temperature available (30°C: 56.1% of observations) and avoided the 2 coldest temperatures (15°C: 5.3%; 18°C: 3.6%). Turtles relocated between chambers more often in control tests than when a gradient was present and fewer observations involved a chamber relocation in control tests. In gradient tests, chamber temperature significantly influenced selection, and the interactive effect of temperature and substrate was significant. We observed turtles more frequently in 30°C in tests conducted with a sand substrate than with a gravel substrate or without a substrate. In tests conducted with sand in the 4 coolest chambers only, turtles chose the warmest temperature with a sand substrate more often than all other temperatures, except 30°C. Our results indicate that hatchling A. spinifera can effectively detect temperature differences and select preferred temperatures within at least a 3°C range and that substrate type may affect selected temperature.

Five species of sea turtles, including leatherback (Dermochelys coriacea), loggerhead (Caretta caretta), green (Chelonia mydas), hawksbill (Eretmochelys imbricata), and olive ridley turtles (Lepidochelys olivacea), were found in the waters east and south of mainland China and the associated islands. Decades of harvesting and habitat degradation have led to a drastic decline in the sea turtle population in the last century. Many foraging grounds and nesting sites have been degraded or have disappeared as a result of human activities. Nowadays, there are only a few nesting sites and even fewer foraging grounds for sea turtles in China. Fishery bycatch is also believed to have been a major cause of sea turtle mortality in recent years. There is an urgent need for more efforts to be focused on the conservation of sea turtles in the region. However, limited information is available, which has impeded the formulation of effective conservation measures. The goal of this paper is to provide an overview on the current population and conservation status of sea turtles, as well as recommendations for their effective management in China.

Podocnemis unifilis and P. expansa abundance was compared at 3 sites in eastern lowland Bolivia in 2000. Two of the sites were adjacent to human communities while the third was not. The comparison was made to examine effects of hunting pressure on turtle abundance. Data suggest that hunting pressure has a negative effect on the abundance of Podocnemis turtles and it is more severe closer to human communities. The greater abundance at a less-hunted site suggests that turtle populations facing reduced hunting pressure may be recovering.

Although barrier island beaches provide important nesting habitat for sea turtles, they are constantly changing. To determine how nesting sea turtles have responded to this dynamic environment, we assessed: 1) wind, current, and tidal patterns and changes in beach profiles, 2) sea turtle nesting patterns, and 3) success of turtle nests deposited along 5 km of beach on Cape San Blas, Florida, an extremely dynamic barrier beach in northwest Florida. From 1998 to 2000, nesting turtles were tagged, nests were monitored, and hatching success was determined. Throughout this study, West beach lost ∼ 5 m of sand while East beach gained ∼ 4 m; however 61% of nests were deposited on West beach and 39% on East beach. Hatchling emergence success did not differ between beaches. Wind direction influenced current direction and sand movement and affected the number of nests deposited along East beach but not on West beach. Nearly all nests (98%) oviposited on both beaches were deposited during a rising tide. Although West beach is narrow and eroding, the steep slope may enable nesting turtles to expend less energy to reach higher nesting sites while still providing successful nests. Nesting on a rising tide and using offshore currents during the internesting period may assist this effort.

A new subspecies of Chelodina mccordi is described from Timor-Leste (East Timor). The nominate subspecies Chelodina m. mccordi is endemic to the small island of Roti to the southwest of Timor. The new subspecies has a very limited distribution in the area of Lake Iralalaro in Lautém District near the eastern tip of Timor-Leste and is endemic to that nation. In some morphological characters, the new subspecies is intermediate between C. m. mccordi from Roti and Chelodina novaeguineae from the island of New Guinea, but, in supporting its subspecific taxonomic status, the new taxon shows more similarities to the nominate form than to C. novaeguineae. The nominate form C. m. mccordi on Roti Island was nearly extirpated by commercial trade in the recent past and has been listed as critically endangered in the IUCN Red List since 2000. Chelodina mccordi is the only species of the genus listed in CITES Appendix II. As a subspecies of C. mccordi, the new taxon from Timor-Leste is automatically included in CITES Appendix II, meaning that any international export of this new taxon to a CITES signatory country requires an export permit from the government of Timor-Leste. This legal requirement will hopefully spare the new subspecies from Timor-Leste the fate of the nominate subspecies from Roti Island, to be nearly driven onto the cusp of extinction through commercial trade shortly after its description as a new taxon.

We present long-term data for hawksbill (Eretmochelys imbricata) nesting in the 2 main rookeries in Brazil: 1) northern Bahia and Sergipe, where the estimated number of nests laid each year increased from 199 in the 1991–1992 nesting season to 1345 in the 2005–2006 season and 2) Rio Grande do Norte, where the estimated number of nests laid in the 2005–2006 season was around 185–475. Adding these results, we estimate that the number of hawksbill nests laid in the 2 main Brazilian nesting grounds in 2005–2006 was between 1530 and 1820 nests. Data on the percentage of hawksbill clutches kept in situ by season in each rookery are also presented. The apparent increasing trend in hawksbill nesting in northern Brazil is encouraging and seems to reflect a range of conservation measures implemented over the past 25 years.

In the 1994 Recovery Plan for the Mojave population of the desert tortoise, Gopherus agassizii, the US Fish and Wildlife Service established 6 recovery units by using the best available data on habitat use, behavior, morphology, and genetics. To further assess the validity of the recovery units, we analyzed genetic data by using mitochondrial deoxyribonucleic acid (mtDNA) sequences and nuclear DNA microsatellites. In total, 125 desert tortoises were sampled for mtDNA and 628 for microsatellites from 31 study sites, representing all recovery units and desert regions throughout the Mojave Desert in California and Utah, and the Colorado Desert of California. The mtDNA revealed a great divergence between the Mojave populations west of the Colorado River and those occurring east of the river in the Sonoran Desert of Arizona. Some divergence also occurred between northern and southern populations within the Mojave population. The microsatellites indicated a low frequency of private alleles and a significant correlation between genetic and geographic distance among 31 sample sites, which was consistent with an isolation-by-distance population structure. Regional genetic differentiation was complementary to the recovery units in the Recovery Plan. Most allelic frequencies in the recovery units differed. An assignment test correctly placed most individuals to their recovery unit of origin. Of the 6 recovery units, the Northeastern and the Upper Virgin River units showed the greatest differentiation; these units may have been relatively more isolated than other areas and should be managed accordingly. The Western Mojave Recovery Unit, by using the new genetic data, was redefined along regional boundaries into the Western Mojave, Central Mojave, and Southern Mojave recovery units. Large-scale translocations of tortoises and habitat disturbance throughout the 20th century may have contributed to the observed patterns of regional similarity.

We determined the relationship between incubation success and physical characteristics of Podocnemis expansa nests on 4 sand beaches of the Araguaia River in the southern Amazon basin, Brazil. Sand samples measuring grain size, humidity, and density were collected during the first 7 days after egg laying. The choice of nest site seems to be more relevant for the reproductive success of a P. expansa than the female's capacity to build a nest.

We tested the hypothesis that handling turtle eggs decreases embryo survival in a well-studied population of midland painted turtle (Chrysemys picta marginata) by comparing embryo survival in handled and nonhandled natural nests during 3 nesting seasons. All nests were protected from mammalian predators. Upon excavation of the nests in the following spring, we found no differences in survival between the 2 treatments, suggesting that the benefits in knowledge gained from nest excavation far outweigh the possibility of a small increase in mortality that could arise from handling the eggs.

The trade traffic estimate was made by using real data from 2 years of seizures (2000 and 2001), combined with river stage-level data. Abufari Reserve is located about 600 km south of Manaus, where the largest stretch of the Amazonian floodplain is protected by a federal conservation unit. In the minds of the local people, the chelonian populations are still abundant and inexhaustible. However, records show that in 2000 and 2001, 3992 chelonians and 122 Podocnemis nets were confiscated, which represent only a small part of the total catch from this river. Consequently, these natural stocks could be decreasing because of trafficking by animal peddlers who invade the area and escape with animals to the detriment of the ecosystem and the local people.

To determine the time interval between embryonic death and physical alterations in appearance of green turtle (Chelonia mydas) eggs, one each of matched pairs of eggs were inverted after 7–10 days of incubation. Chalkiness of the white spot diminished after 44 hours as maintenance of the chorio-allantoic membrane, contributing to the opaque appearance of viable eggs, ceased after embryo mortality. Results of this study will allow embryo mortality to be attributed to known specific events or conditions within the incubation period.

Eight genera and 14 species of fungi were isolated from soil and eggshells samples collected from the nesting site of the green sea turtle (Chelonia mydas) at Ras Al Jinz Reserve, Oman. The genus Aspergillus was the commonly represented, including 6 species: A. flavus, A. niger, A. terrus, A. nidulas, A. fumigatus, and A. ochraceus. Seventy-five percent of A. flavus strains isolated from eggshells were aflatoxigenic, producing aflatoxins in a concentration range of 0.3–28 ppb. The growth of fungi on turtle eggs and secretions of mycotoxins may affect embryonic development and possibly contribute to the green turtle egg mortality.

Laparoscopies were performed on 225 hawksbill turtles (Eretmochelys imbricata) following nesting emergences on Milman Island, northern Great Barrier Reef, Australia during the 1992–1995 summer seasons. New recruits (first time breeders) made up between 9.8% and 14.3% of the nesting population across 4 summer seasons. Remigrants were not significantly larger or heavier than recruits, indicating that females nesting for the first time do not necessarily recruit to a nesting population at the smallest sizes. Further investigations are required to determine if the summer recruitment rate is reflective of the entire nesting population, which nests year-round.

We present a long term record (1984–2004) of registered occurrences of Kemp's ridley turtles in the marine zone and nesting beaches of the Yucatan Peninsula, Mexico.

The South China Sea is one of the most important areas for sea turtles in China. Taipin Tao is the largest island in the Nansha Archipelago and is a nesting site for green and, possibly hawksbill, turtles. Satellite telemetry studies from the year 2000 till 2003 demonstrated that the green turtles nesting at Taipin Tao are a shared natural resource among the nations in the southern South China Sea. Regional and international cooperation overseen by international organizations is desperately needed for the effective protection of the green turtles nesting at Taipin Tao.

We report on the first confirmed occurrence of Lepidochelys olivacea nesting in Ecuador based on the presence of eggshells and the identification of a late-stage embryo at a beach located in Manta (lat 0.94°S, long 80.7°W), Manabí Province, Ecuador, in October 2004. This is the second-most-southerly record of olive ridley nesting on the Pacific coast of South America.

Movements of a bog turtle, Glyptemys muhlenbergii, outside of characteristic wetland habitat were recorded using radiotelemetry. Data suggest that permit reviewers and park managers should consider the conservation implications of stream use, undercut banks, and streamside habitat in formulating mitigation and management plans within the range of this federally protected species.

We report several boat propeller- and fishing-related injuries sustained by eastern spiny softshell turtles (Apalone spinifera) from the northern Lake Champlain basin of Québec and Vermont. These incidents may have negative impacts at the population level when added to habitat alterations and other mortality factors challenging this threatened and isolated northern population.

Aural abscess incidence in 22 painted turtle (Chrysemys picta) populations in Minnesota averaged 0.7% (range, 0.0%–9.1%) of more than 2700 captured turtles. Results indicate the need for more research regarding incidence and causes of aural infections in turtles and possible directions for future work are suggested.

Northern diamondback terrapins, Malaclemys terrapin terrapin, were tagged with passive integrated transponder tags to mark them and monitor their activity along a road through salt marsh habitat in Tuckerton, New Jersey. A mark-recapture study was conducted to evaluate terrapin movements, nesting frequency, and nest site fidelity. During sampling periods throughout 2 nesting seasons (2004–2005), 300 adult females were tagged. Ninety-two recaptures were made of 54 individual terrapins, with most recaptures (81.5%) occurring within a season (range = 1–45 days, mean = 7.5 days). Some recaptures (18.5%) occurred the following year. Some females crossed the road multiple times during nesting, and nearly half searched for a site within 50 m of the area where they were initially tagged. Nest site selections of all multiple nesters (within and among seasons) varied greatly from approximately 4–1307 m (mean internesting distance = 202.75 m), yet 39% were recaptured within 50 m of their initial tagging location. One-third of yearly nesters showed an internesting distance within 25 m of their initial-year tagging location. These results indicate that some females travel variable distances between nest sites and may demonstrate evidence of nest site fidelity.

Many of the world's turtles and tortoises are currently threatened with population extinction. Some species are so threatened in their native habitats that the only way to ensure their survival may be through captive propagation, an endeavor in which many private conservation organizations are currently engaged. In this review we outline the genetic issues that need to be considered when establishing captive breeding colonies of tortoises and turtles for eventual reintroduction or population supplementation. The first section of this review stresses the importance of creating breeding units that are based on the population structure of a species in its native range. We discuss how molecular methods and the concepts of evolutionarily significant units (ESUs) can be used to define breeding units for captive breeding colonies and determine their geographic origin for reintroduction. In the second section we discuss the need to maintain the genetic variability of the colony members and the techniques that are available to achieve this goal.

From 1978 to 2006, oviposition was induced in 13 North American turtle species. Of 245 inductions, 195 used oxytocin alone, 22 used arginine vasotocin (AVT) alone, 13 used a combination of oxytocin and ketamine, 8 combined propranolol and oxytocin, and 7 used propranolol and AVT. For wild Chrysemys picta picta, oxytocin-induced eggs were as viable as natural nest eggs. Suggested dosage ranges for oxytocin used alone vary from 0.7 to 4.0 units per 100 g, depending on species. In species where more than 28 animals were injected with the suggested dosage all eggs were oviposited after the first injection between 74% and 82% of the time. With a second injection, all eggs were laid between 83% and 94% of the time. It would be desirable to find a combination of easy-to-use drugs that yielded a higher success rate with the initial injection, especially for species with a history of not responding to oxytocin. Although only small numbers (13 animals) were involved, there was a suggestion that the combination of ketamine and oxytocin may prove more effective than oxytocin alone. A significant adverse effect observed with oxytocin induction was that some successfully induced turtles still displayed nesting behavior over the following days to weeks. This adverse effect might increase the risk of predation or trauma to wild animals after treatment with oxytocin. It might be avoided by using a more physiologic drug combination to induce oviposition rather than oxytocin alone. Natural oviposition is complex and, at least, involves the interaction of peripheral beta-adrenergic neurons, AVT, and prostaglandin F_2α (PGF). Other, more physiologic approaches to induce oviposition might be to use a beta-adrenergic blocker with oxytocin or PGF, PGF   oxytocin, PGF   ketamine, or oxytocin   ketamine.

Oxytocin dosage was determined experimentally for the red-eared slider (Trachemys scripta elegans). Five dosages including 20, 10, 5, 4, and 2 units/kg were experimentally compared in 253 female turtles in a series of experiments conducted in 1999 and 2000. The 3 highest doses were equally effective overall following a maximum of 2 injections. The 2 lower doses were equally effective overall following a maximum of 2 injections. Success rate (i.e., turtles laid all eggs or retained 2 or fewer eggs following a maximum of 2 injections) ranged from 100% (20 and 10 unit/kg doses) to an average of 88.9% for the lowest doses (4 and 2 units/kg). When reduction in oxytocin exposure is desired, the lower dosages are recommended; when turtles are being treated for egg retention, the higher dosages may be more desirable. No difference in oxytocin efficacy was found among 3 species of chelonians (red-eared slider; stinkpot, Sternotherus odoratus; and painted turtle, Chrysemys picta) when oxytocin was given at 4 units/kg. No difference in efficacy was found among 2669 red-eared sliders from 2 collecting areas in west-central Illinois induced with 4 units/kg between 2000 and 2005.