We present results of an inwater research program focusing on basic ecology of juvenile hawksbill turtles (Eretmochelys imbricata) in the Cayman Islands. We made 206 captures of 135 hawksbills in Little Cayman and 103 captures of 97 hawksbills in Grand Cayman. The Cayman Islands aggregation demonstrated a broad size distribution (20.5–62.6 cm straight carapace length), slow growth rate (3.0 ± 0.9 cm/y), and multiple recaptures, suggesting long-term residence in some individuals. Demonstrated home range was small (mean distance from capture to recapture 545 ± 514 m, range 2–2080 m); although, an international tag return suggested a long-range developmental migration. Vertical features provided important habitat in Little Cayman, and larger turtles were generally captured in deeper waters. Behavior at sighting varied by habitat: resting, swimming, and feeding were observed in coral reef, reef wall, and hardbottom colonized by sponges and gorgonians, and resting was frequently observed in uncolonized hardbottom. Images obtained from underwater photographers show that hawksbills forage on sponges and occasionally on jellyfish. We observed an apparent commensal feeding relationship between hawksbills and 3 species of angelfish as well as aggressive interactions between hawksbills. We also documented causes of injury and mortality in the study area—including legal, illegal and incidental take, vessel collisions, hurricanes, and natural predation.

Based on customs trade statistics from 1999 to 2008, a total of 1989 metric tons of shells of hard-shelled chelonians have been imported into Taiwan for consumption in the traditional Chinese medicine (TCM) market, with an average of 198.9 metric tons/y. The total amount of soft-shell turtle shells imported was 290 metric tons, averaging 29.0 metric tons/y. This volume indicates that millions of turtles and tortoises have been killed annually for the TCM market in Taiwan alone. The trade of turtle shells for TCM has existed in huge volumes for a long time, with no significant decrease in the market size through Convention on International Trade in Endangered Species of Wild Fauna and Flora listing of the main target species. Although the customs trade records were not species-specific, in the market survey conducted in 1996–2002, a total of 39 species of turtles and tortoises, mainly originating from China, Southeast and South Asia, were identified. Only 3 non-Asian species were found. The larger number and numerous species of origin in turtle-shell trade for the TCM market indicate blatant disregard by traders for law and authority of responsible agencies from both source and consumer countries. Observed levels of usage and trade of turtle shells appear to be highly unsustainable and may have a great impact on the chelonian fauna in source areas. For the sustainability of chelonian fauna in Asia, clear policies and close international cooperation for the regulation of turtle-shell trade are urgently needed.

Although the olive ridley sea turtle (Lepidochelys olivacea) is the most abundant sea turtle in the world, the species has exhibited a significant decrease in the size of arribadas at Nancite Beach, Costa Rica, since its discovery in 1970. In the present study, we compiled data on number of nesting females per arribada from previous authors for the period 1971–1997 and collected new data using a total count methodology and a strip transect method for the arribadas during 1999–2007. We used generalized additive models to assess the trend of arribada size for the period 1971–2007. Our data indicate a significant reduction of 42%, 84%, and 90% in the number of nesting females per arribada in the periods 1971–1984, 1971–1992, and 1971–2007, respectively. Although we could not determine the specific reasons for this attrition we speculate that this decline may be driven by embryo-associated mortality due to a poor nest microenvironment in this beach. Our data confirm that the Nancite arribada population has undergone a significant decrease over the past 36 years but that the population currently appears to be at a stable low point. In addition, our data show that hatchling production may be increasing at this beach, which suggests the possibility that this population may recover over a few decades. The significant attrition observed in this study underscores the ephemeral nature of arribada populations in general and the need for the continued monitoring of the Nancite population.

Hatchling marine turtles emerge at night from underground nests, enter the ocean, and swim offshore. Here, we measured the intensity (hours swimming) and the temporal patterning (diurnal vs. nocturnal expression) of activity shown by Malaysian (Sulu Sea) hawksbill (Eretmochelys imbricata) and green turtle (Chelonia mydas) hatchlings tethered inside pools for six days, postemergence. The results were compared to the activity shown during the same period of development by sea turtles in Florida. The two species from Malaysia showed significant differences in activity both from one another and from the Florida (leatherback, Dermochelys coriacea; loggerhead, Caretta caretta; and green turtle) species. Hawksbills were less active than the hatchlings from Florida, swimming on average < 6 h/d. Hawksbills did not show a frenzy period of hyperactive swimming, typical of the first day of offshore migration by the hatchlings from Florida. Green turtles swam on average about 17 h each day during a two-day frenzy period that was one day longer than the frenzy period shown by green turtles from Florida; thereafter, activity showed a significant decline. These results suggest the two species use different strategies to avoid predators near shore. Hawksbills may hide in flotsam or remain inactive to minimize detection; whereas, green turtles may reduce their exposure time by rapid locomotion through shallow water. We conclude that the frenzy period shown by hatchlings during offshore migration is a variable trait both among marine turtle species and between green turtle populations nesting on Western Atlantic and Sulu Sea beaches.

Previously, we showed that during their first six days of swimming hawksbill hatchlings are less active than the hatchlings of other marine turtle species. Here, we document that hawksbills also employ slower, drag-based swimming gaits during the brief periods when they do swim. These gaits may render the turtles less conspicuous to predators that detect prey on the basis of movement. Over the 6-day period of observations, predominantly drag-based locomotion (by “rear-flipper kicking” and “dogpaddling”) was gradually replaced by a larger proportion of “power stroking”, a more powerful and faster lift-based means of locomotion. Under natural conditions, this change probably occurs after the hatchlings have reached deep water where predator concentrations are lower. Hawksbill hatchlings are smaller than those produced by most other marine turtles, suggesting that their unique migratory strategy might be correlated with insufficient power to swim rapidly. However, a comparison among species of marine turtle hatchlings suggests that size is poorly correlated with swimming speed. We hypothesize instead that both hatchling size and swimming speed independently determine vulnerability to inshore fish predators. Thus, hawksbills may opt for “hiding by flotsam mimicry” because their size makes them vulnerable to so many fish predators. Therefore, their slower swimming speed may be a consequence, rather than a cause, of that strategy.

Recent evidence suggests that higher sea-surface temperatures are affecting nesting patterns in loggerhead turtles (Caretta caretta), specifically by causing nesting to begin earlier in years with higher oceanic temperatures. I tested whether a sympatrically nesting species (Chelonia mydas) also shows the same pattern and found that green turtle seasonal nesting patterns at Canaveral National Seashore, Florida, were unrelated to environmental temperatures at the nesting beach; although, the date of the first nest predicted the magnitude of the nesting season (nesting earlier in the year led to higher numbers of nests). Although the reasons for differences in loggerhead and green turtles remain unclear, these results indicate that the timing of loggerhead turtle nesting may change in a warming environment; whereas, green turtle nesting may remain relatively fixed with regard to temperatures at the nesting beach.

Performance payment conservation approaches are based on a willing buyer–willing seller model. Sellers deliver conservation outcomes in exchange for a negotiated payment in cash or in kind. The use of performance payments to achieve conservation outcomes is increasingly being used as an alternative to traditional regulatory and development-based approaches in low-income nations. Although payments are increasingly common in terrestrial species and ecosystem conservation initiatives, they are rare in marine conservation efforts such as sea turtle protection. This paper describes sea turtle incentive payment initiatives taking place around the world, most of which are found in projects focusing on nesting beach protection. We find that many of these initiatives have achieved substantial results for a very low annual cost. The potential for expanding payment incentive schemes beyond nest protection to reduce bycatch and hunting pressures on juvenile and adult turtles is unknown but should be further explored.

This study evaluates the potential impacts of the release of the giant tortoise, Dipsochelys arnoldi, to vacant habitat within the species' presumed historic range. Five individuals (3 males and 2 females) were released in December 2006 in the isolated Grande Barbe area of Silhouette Island, Seychelles. A comprehensive vegetation survey of all plant species within feeding height of the tortoises in Grande Barbe was conducted. These data, combined with daily feeding observations, were used to calculate feeding rates and diet preferences. Tortoises were observed to have a mean diurnal active time of 257 minutes per day exhibiting a mean feeding rate of 3.86 g of plant material consumed per minute of active time. Individuals were recorded feeding on 18 of 26 recorded plant species, 9 of which were selectively foraged. Species composition of plant species ingested differed between sexes. Males selectively foraged on 6 plant species and females selectively foraged on 7 species. Only 2 plant species were selectively foraged by both sexes.

We studied the reproductive, nesting, and hatchling ecology of the endangered Alabama red-bellied cooter (Pseudemys alabamensis) from 1997 to 2001 and in 2003 in the Mobile–Tensaw Delta, Alabama, USA. Nesting activity peaked in June and July and mean clutch size was 13 eggs (n = 31), with a strong positive correlation between clutch size and female carapace length. Females may lay multiple clutches in single- or multiple-chambered nests; adult and juvenile females dig false nests. Nonoverwintering hatchlings had a development period of 101 days (n = 21 nests); overwintered hatchlings emerged beginning in March of the next year. Mean hatchlings weight was 11.7 g with a carapace length of 39.1 mm (n = 262). We tested a headstart program on 6 hatchlings raised in captivity for 16 months and released as large, juvenile turtles; results suggest that the headstart program is a feasible approach to increase juvenile survivorship. We propose the following plan to prevent further population declines: 1) construction of a permanent barrier to prevent nesting females and hatchlings from being killed by vehicular traffic on the Causeway (US 90/98), 2) limitation of disturbance to nesting habitat in the Mobile–Tensaw Delta, and 3) initiation and evaluation of a 1-year headstart program to increase recruitment.

Alligator snapping turtle (Macrochelys temminckii) populations have declined across much of the southeastern United States in recent decades, due at least in part to overcollection. Recently, however, legal protection from large-scale harvesting has been granted to the species in all states where it is native, thereby drastically reducing one of the greatest threats to its survival. There is growing interest in captive propagation of alligator snapping turtles for reintroduction where populations have been decimated. In conjunction with one such effort, we analyzed the physiological effects of temperature on embryonic and posthatching development. Results indicate that extreme high and low incubation temperatures negatively affected embryo survival, and high incubation temperatures corresponded with shorter incubation time but also produced smaller hatchlings. The effects of temperature on gonadal differentiation indicated that the upper pivotal temperature was approximately 27.5°C. Posthatching growth was faster at warmer water temperatures, and there was little to no acclimation of metabolic rate to exposure to either incubation or water temperature. We conclude that intermediate (27.5°–28.5°C) incubation temperatures produce a female-biased mixed sex ratio and maximize hatching success and hatchling size while increasing incubation duration only slightly over that at the higher temperatures. In addition, posthatching growth was positively influenced by hatchling body temperature; therefore, warmer water temperatures (∼30°C) decreased the time required to rear turtles to a size suitable for reintroduction.

The radiated tortoise (Astrochelys radiata), endemic to the spiny forest of southern Madagascar, had virtually never been studied in the wild until the late 1990s. Recent research projects and surveys have contributed to defining the extent of the decline of the species, and it now appears that A. radiata faces serious extinction risks unless current trends are halted. As part of an ongoing conservation genetics project concerning the species, we investigated genetic diversity and differentiation of the isolated tortoise population from Parc National d'Andohahela (PNA), considered as one of the last remaining sanctuaries of the species in the southeast, where Antanosy people consume tortoise meat. Genetic diversity at PNA was similar to other populations, but differentiation was the greatest of all sites sampled, emphasizing the conservation value of this population. However, our most important finding was that the majority of captured tortoises at PNA were relatively small males, indicating that recruitment may be very low. We found physical evidence that Antanosy poachers are removing the largest individuals from the population, despite their official protection within the park. We discuss conservation issues related to A. radiata, including the role of protected areas in Madagascar, the importance of understanding the taboo toward tortoises in Antandroy and Mahafaly communities, and the pertinence of the current Convention on International Trade in Endangered Species listing of the species.

Three kyphotic Emydura macquarii krefftii that appeared in good health were recorded. Kyphotic turtles from other studies also appear to be able to feed and reproduce readily, thus showing this deformity may have minimal affects on a turtle's biology.

Charles Alexandre LeSueur discovered the common map turtle Graptemys geographica in 1816. He named the species Testudo geographica in 1817 and described it with a drawing of a specimen he collected from a Lake Erie marsh, but further details on the collecting locality were not given. I designate the drawn specimen as the lectotype of the species and review historical documents and specimen records that allow restriction of the type locality to the peninsula of Presque Isle and adjacent Presque Isle Bay in Erie County, Pennsylvania.

Recreational and commercial crab pots are considered major threats contributing to recent declines in diamondback terrapin populations. In a single Georgia (USA) tidal marsh, 133 diamondback terrapin (Malaclemys terrapin centrata) carcasses were observed in abandoned crab pots, consisting of more than double the remaining estimated population. We suggest that the potential for just a few neglected or abandoned crab pots to significantly deplete a terrapin population makes enforcement of explicit soak laws and implementation of a derelict crab-pot removal program a priority for conservation of diamondback terrapins in Georgia.

We report on a green turtle, Chelonia mydas, captured along central coastal Queensland, Australia, that had a cloacal opening on the dorsal side of its tail. Here we describe the internal anatomy and possible embryonic development of this abnormality and discuss the functional and reproductive implications for this turtle. To our knowledge, this is the first report of an ectopic cloaca (supra-caudal vent) deformity occurring within any turtle, tortoise, or terrapin species.

We report on an intersex green turtle, Chelonia mydas, observed at Raine Island, Australia that externally resembled an adult male but internally—based on laparoscopic examination—had both ovarian and testicular structures resembling those of an adult. This individual was the first intersex turtle that has been recorded on a nesting beach during the 39 years of extensive census studies in Queensland. Its observation confirms that the definitive identification of sex with marine turtles remains dependent on observations of their gonads or on observing eggs being laid.