Foraging grounds are critical to the survival of marine turtles, yet studies of these areas lag behind those of nesting sites. Our study represents the first data and discussion on marine turtle distribution, abundance, and health at a marine turtle foraging ground in the central Pacific, Palmyra Atoll National Wildlife Refuge, which constitutes a regionally important mixed-size-class foraging ground for green turtles (Chelonia mydas) and, to a lesser extent, for hawksbill turtles (Eretmochelys imbricata). Surveys and anecdotal reports suggest that nesting activity is rare, and we have confirmed the presence of limited suitable nesting habitat. During in-water activities from 2008 to 2011, we caught 211 green turtles ranging from postpelagic juveniles to adults (weight: mean  =  44.6 kg, range  =  7.2–146.3 kg; curved carapace length (CCL): mean  =  69.7 cm, range  =  41.0–113.6 cm) and 2 juvenile hawksbills (weight₂₀₀₉  =  16.3 kg, CCL₂₀₀₉  =  57.0; weight₂₀₁₁  =  11.2 kg, CCL₂₀₁₁  =  50.5 cm). Body condition indices did not significantly differ by year of capture. These indices, along with the absence of observed fibropapilloma tumors, indicated that turtles at Palmyra Atoll were on average in very good condition. We also conducted 11 relative abundance surveys from 2005 to 2011, a subset of which revealed an uneven distribution of turtles around Palmyra Atoll with 3 hot spots of turtle abundance off the flats to the north, south, and east. By linking several aspects of our research program with similar efforts at foraging grounds throughout the Pacific Basin, we can further our understanding of poorly known regional migratory connectivity.

The Bocas del Toro region of Panamá (Bocas del Toro Province and the Comarca Ngöbe-Buglé) has been known as an important area for sea turtles since at least the 17th century. Four species occur in the region: the hawksbill (Eretmochelys imbricata), green turtle (Chelonia mydas), loggerhead (Caretta caretta), and leatherback (Dermochelys coriacea). Multiple life stages of these species are supported by the diverse marine habitats and beaches in the region. We summarize the evidence for stages present and their known distributions in the Bocas region. Annual nest numbers, location, and monitoring status are given for 17 nesting beaches. These beaches support regionally significant numbers of leatherback and hawksbill nests, small numbers of green turtle nests and, rarely, loggerhead nests. We review the history of sea turtle use in the Bocas region and describe “velación,” a government-organized system that facilitated the extraction of hawksbills from nesting beaches throughout the Bocas region during the 20th century to supply the market for tortoiseshell. Current threats to sea turtles in the Bocas area include an illegal directed take of turtles at sea and of eggs and turtles on nesting beaches, bycatch in lobster and shark fisheries, and habitat degradation. Coastal development and increasing tourism have gradually become concerns for sea turtle conservation as the economic focus of the region has changed. The history of conservation efforts on behalf of sea turtles in Bocas is also summarized. This contribution was originally written to provide data on sea turtles for a coastal management plan for the region.

La región de Bocas del Toro de Panamá (Provincia de Bocas del Toro y la Comarca Ngöbe-Buglé), ha sido conocida como un área importante para las tortugas marinas desde por lo menos el Siglo XVII. Esta región alberga cuatro especies: la tortuga carey (Eretmochelys imbricata), verde (Chelonia mydas), cabezona (Caretta caretta), y baula (Dermochelys coriacea). Múltiples etapas de vida de estas especies están sostenidas por los diversos hábitats marinos y playas en la región. Resumimos la evidencia por etapas presentes y su conocida distribución en la región de Bocas. Números de nidos anuales, localización, y estado de monitoreo están dados por 17 playas de anidación. Estas playas sostienen regionalmente números significativos de nidos de baulas y carey, pequeños números de nidos de tortuga verde, y rara vez, nidos de cabezonas. Al revisar la historia del uso de tortugas marinas en la región de Bocas, describe la “velación”, un sistema organizado del gobierno que facilitaba la extracción de tortugas carey de las playas de anidación a través de la región de Bocas durante el Siglo XX, para suplir el mercado de concha de carey. Las actuales amenazas que enfrentan las tortugas marinas en el área de Bocas incluye, cosecha ilegal de tortugas directamente en el mar y de huevos y tortugas en playas de anidación, la captura incidental de langosta y pesquería de tiburón, y degradación del hábitat. El desarrollo costero y el crecimiento del turismo se han convertido en preocupaciones para la conservación de las tortugas marinas, ya que el enfoque económico de la región, ha cambiado. Además, se ha resumido la historia de los esfuerzos de conservación en favor de las tortugas marinas, en Bocas. Esta contribución fue originalmente escrita para proveer información de tortugas marinas para el plan de manejo costero de la región.

Coastal development can alter the natural dynamics of beach environments, with strong implications for associated biota. Sea turtles nest on oceanic beaches and often depend upon a specific range of conditions for successful nesting. In the case of the critically endangered leatherback turtle (Dermochelys coriacea), we know little regarding what features they select for nest sites, including how they respond to anthropogenic development. We examined relationships between leatherback nest frequency, beach environments, and tourism development at Playa Grande, Costa Rica, the location of the largest current nesting population in the eastern Pacific Ocean. Developed beach sections had shallower slopes, lower pH, and less air-filled pore space, but higher water content and salinity than undeveloped areas. Developed areas were also comprised of more sand in the smaller grain size classes relative to undeveloped sections. Leatherback nesting was positively correlated with deepness of the offshore approach, beach slope and elevation, pH, and sand in intermediate size classes (0.025-mm diameter), but negatively correlated with sand in the smallest silt size class (< 0.0625-mm diameter). Leatherback nesting frequency was 3.4 times higher in undeveloped sections of the beach relative to developed areas, while nonnesting emergences were 2.6 times more likely in developed relative to undeveloped areas. It is apparent that coastal development has impacted beach environments with consequences for leatherback nest site distribution. It is likely that additional development of the beach under mixed-management plans to support a growing tourist industry will further degrade the attractiveness and quality of the beach for leatherback nesting.

It has become widely recognized that a large gap exists in the global knowledge of fisheries due to the continued oversight of the small-scale sector. For populations of marine turtles restricted to the eastern Mediterranean, bycatch in small-scale fisheries is a concern. By using North Cyprus as a case study for the region, we used anthropological methods to estimate the magnitude of marine turtle bycatch, while presenting novel information on the marine turtle life stages using the coast and profiling the fishery itself. Our analyses suggest that as many as 1000 turtles may be caught annually by this fishery with an estimated mortality rate of 60%. Trammel nets were the main cause of marine turtle bycatch. Strandings coincided with setting of trammel nets that target siganids (Siganus luridus and Siganus rivulatus) and the majority of bycatch registered by fishers were caught in these gear types. We demonstrate a relatively simple approach to evaluating marine turtle bycatch, providing information that will allow local authorities and conservation groups to direct further research and possible mitigation measures.

Astrochelys radiata is one of the threatened tortoise species of Madagascar. We studied their home range size, use of shelters, and diet in Tsimanampetsotsa National Park. The goal was to identify suitable habitats and food chemistry. These data could serve as bases for future evaluations of the suitability of habitats under altered environmental conditions, such as degradation and climate change. The study was performed with the help of radio-tracking in two different types of vegetation: dry deciduous forest on sand and spiny bush on limestone between November 2007 and October 2008. Monthly range sizes were 2.3 ha in the littoral forest and 1.4 ha on the limestone massif when calculated with the kernel method. Based on the minimum convex polygon, the values were 1.0 and 0.5 ha, respectively. Monthly range size did not vary significantly between sexes, but range sizes were larger in the littoral forest than on limestone. A. radiata chose shelters under trees with large trunk diameters (> 15-cm DBH) and lower heights than trees in representative samples in the habitats. Plant items eaten and not eaten by this species were analyzed for primary and secondary plant chemicals. A. radiata consumed a wide variety of plants. Its diet was composed of leaves (91%), flowers (5%), and fruits (4%) from 109 plant species. During the dry season, high energy content was the most important factor for food selection by A. radiata.

The giant tortoises (Aldabrachelys or Dipsochelys) of the Indian Ocean Islands have been in decline since the first human settlement of the islands. They retain only a single natural population on Aldabra Atoll (and possibly Ile aux Cerfs, where tortoises are descendants of a mixture of indigenous and imported animals). Several additional wild populations are known, resulting from reintroductions to the historic range and introductions outside of that range. The historical distribution of tortoises in Seychelles is summarized, with reliable tortoise records from only 4 coralline islands and 23 granitic islands and the status of all the wild populations reviewed. This includes the first census of the Frégate Island population. In the granitic islands, only 9 islands support tortoises today and the wild population of these islands is estimated at 500–550 adults. In the coralline islands, tortoises are now present on 11 islands, with a total population of over 100,000 (almost all on Aldabra). Climate change impacts over the next 100 yrs are expected to be severe in low-lying areas of the Seychelles Islands attributable to sea-level rise and storm impacts on coastal erosion. These are projected to result in the loss of many populations and significant declines in the Aldabra population. As a result, the species should be regarded as Vulnerable by IUCN Red List Threat Criteria. Reintroduction to more of the high granitic islands could offset some of these projected declines, and it is recommended that such reintroductions be included in future conservation programs to restore ecosystem function.

Freshwater turtle courtship is an exciting and potentially phylogenetically important field of study. Scattered data exist from the past century of research, yet no recent summary is available. Courtship in freshwater turtles includes a number of common behaviors, which usually involve visual, tactile, olfactory, and auditory signals. These signals function in both species and sex recognition and in the seduction of potential mates. Specific behavioral sequences are required to facilitate successful copulation, and these behaviors presumably play a role in mate choice. We performed a series of meta-analyses to investigate the evolution of courtship behavior in freshwater turtles. Biting, an aggressive form of courtship behavior, is plesiomorphic, conserved only in the Chelydridae, Kinosternidae, subfamily Emydinae and South American species in the Pleurodira. Head movement and foreclaw display are apparently apomorphic and evolved independently in the Geoemydinae, Deirochelyinae, and Australian species of the Pleurodira. Display type (pre- or postmounting display) and sexual size dimorphism also show phylogenetic patterns. Therefore, the evolution of courtship behavior in freshwater turtles might accompany the evolution of sexual dimorphism, which is directly subject to natural selection.

Understanding of evolutionary history and speciation events to inform phylogeography of extant species can be gleaned from the fossil record. However, the fossil record for Australian freshwater turtles contains many gaps and interpretation of the fossils that are known is difficult because of poor knowledge of the morphology of extant forms. There are no fossils currently assigned to short-necked turtles in the genus Myuchelys. In an alternative approach, morphological characters of the extant species Myuchelys bellii, Myuchelys georgesi, Myuchelys latisternum, and Myuchelys purvisi were mapped against their current molecular phylogeny. The cryptic species pair, M. georgesi and M. purvisi, are morphologically very similar, but distant phylogenetically, and their common ancestor includes M. latisternum and M. bellii in its decendents. This suggests that current shared morphology of M. georgesi and M. purvisi represents a suite of symplesiomorphies (shared primitive characters). These characters include presence of a cervical scute, lack of prominent neck tubercles, a relatively small head size, minor or no serrations of marginal scutes, an oval carapace, and a smooth head shield extending down the parietal arch toward the tympanum. This commonality of characters of this cryptic species pair represents a rare insight to the ancestral phenotype of the Myuchelys. The loss of the cervical scute and presence of enlarged neck tubercles, a large robust head and furrowed head shield, deep serrated shell margins, and compressed shell profile in M. bellii and M. latisternum are synapomorphies (shared derived characters). There is no morphological support for the distinction at the level of species or subspecies between discrete populations of M. bellii. A dichotomous key to species is provided.

The twist-necked turtle (Platemys platycephala, Schneider 1792) is the only member of the genus Platemys. Despite a pan-Amazonian distribution in South America, ecology and population status of this small, forest-dwelling species are unknown in many countries within its range. Currently it is not listed in the IUCN Red List of Threatened Species, and there are almost no published data on reproduction, feeding, or habitat preferences in the wild. In this article, observations on habitat selection, short-term movements and feeding in the Nouragues Field Reserve, French Guyana, are reported for the first time. Study specimens used the same areas in the late rainy season of 2009 and 2010, moving total distances of 503–686 m over a period of approximately 3 wk within calculated areas of activity ranging in size between 0.73 and 1.59 ha. The main habitats used were palm swamps, temporary flooded forest, and primary nonflooded forest. The analysis of 4 stomach and 2 fecal samples showed that different classes of insects, worms and crustaceans as well as amphibian eggs were consumed as food items.

We describe here the feeding habits of the Yellow-spotted River turtle (Podocnemis unifilis) (n  =  20), Geoffroy's side-necked turtle (Phrynops geoffroanus) (n  =  10), and Gibba turtle (Mesoclemmys gibba) (n  =  4) from central Peru, Pasco Department, and evaluate food overlaps among them. Podocnemis unifilis showed a generalist feeding habit, ingesting animal and plant matter, but tending to be herbivorous, because plant matter made up 62.9% of the volume vs. 3.9% for animal material. The most important items in P. unifilis diet were seeds from the Fabaceae (Leguminosae) family and bark. Podocnemis geoffroanus and M. gibba also had generalist feeding habits. The most important items for P. geoffroanus were insects, especially Libellulidae larvae, and plant material. Mesoclemmys gibba ingested insects, fish, crustaceans, unidentified plant matter, bark, leaves, stem, and algae, with plant matter being more representative by frequency and volume. Low dietary overlap was observed between P. unifilis and P. geoffroanus, and both species appeared to overlap with M. gibba. To our knowledge, this is the first quantitative dietary study of Peruvian freshwater turtles, and the first diet analysis of wild M. gibba in the Amazon basin.

In reptiles, the hatching and emergence of a single clutch may be synchronized or may take place over a number of days, weeks, or even months, depending primarily on the microenvironment of the nest. The present study focused on the patterns of hatching and emergence of Podocnemis unifilis hatchlings in an area of várzea floodplain on the lower Amazon River in Santarém, in the Brazilian state of Pará, in 2007 and 2009. Two groups of nests were monitored for hatching and emergence, with the nests in one group being undisturbed during the entire study period. The difference between the oviposition–hatching and oviposition–emergence intervals was determined based on the monitoring of these processes in the monitored clutches. Hatchlings took 1.5 d to leave the eggshell and the eggs at the top of the nest hatched first. The size of the clutch influenced the length of the interval between the first and last hatching. Most hatchlings emerged from a nest during a single night. Hatchlings in late nests and those closer to vegetation took significantly longer to emerge. The hatching–emergence interval was greater in 2007 (11.0 d) than in 2009 (7.3 d). This study contributes to the understanding of hatching and emergence patterns in P. unifilis and the physical and environmental factors that influence them, including the variation between reproductive seasons.

Podocnemis unifilis is found throughout the Amazon basin, where it has been harvested as a highly valued source of animal protein since precolonial times. Harvesting rates are also lower during the flooding season due to the availability of habitat for turtle dispersal. This study investigated the effects of the hydrological cycle and human impacts on the abundance and population structure of the species on the middle Xingu River between September 2007 and March 2008. The highest density of basking turtles was recorded during the flooding period, while the number of specimens captured in hand nets was greater during low water. Density and capture rates varied positively with increasing distance from Altamira, the study area's main urban center. Consequently, the abundance of P. unifilis was affected negatively by proximity to urban centers. In the Great Bend area of the Xingu River, densities and abundance were lower, and the mean size of the animals was smaller. These results likely reflect the effects on local stocks of the presence of local gold-prospecting operations and, thus, more harvesting pressure on the P. unifilis population. The sex ratio was biased in favor of males (1.90∶1), possibly as a result of preferential harvesting of females, which are larger in size than males and are often laden with eggs. Further long-term studies are needed to better understand the impact of anthropogenic pressures on long-lived organisms such as turtles. In addition, such information would aid the ecological sustainability of turtles in the Amazon Basin that provide rural communities with subsistence resource.

Podocnemis sextuberculata is cited as “vulnerable” on the International Union for Conservation of Nature Red List due to a decline in its population as a result of the intensive exploitation pressure throughout its range. Understanding the effects of environmental characteristics and human activities on turtle populations is essential to improve current conservation programs. We analyzed the abundance of Podocnemis sextuberculata in the lower Amazon, where a management experiment is under way, by comparing neighboring areas with and without community-based management (CBM) initiatives. In addition, we analyzed the influence of environmental variables on the species' abundance. Abundance was measured by captures per unit effort expressed in number of individuals (CPUE_N) and biomass (CPUE_B). The effects of CBM and environmental variables were tested by General Linear Model analysis. A total of 354 individuals were captured, 321 in the areas under CBM and 33 in areas without CBM. CPUE_N and CPUE_B were strongly correlated, and their values were about 10-fold higher in the areas carrying out CBM initiatives. The variable that best explained variation in CPUE_N and CPUE_B was CBM. Distance between the sampling point and the nearest nesting beach and river level also influenced capture rates. Results clearly show that local fishing restrictions can have a positive influence on turtle populations.

Adult mortality at the nesting site is an important demographic parameter for green turtles (Chelonia mydas) at Aldabra Atoll, Seychelles, where, between 1995 and 2008, records were kept of adult green turtles found dead (n  =  158) or so trapped or incapacitated in the vicinity of the nesting beaches as to be unable to return to the sea without human assistance (n  =  50). The main cause of death (n  =  121) was entrapment and/or incapacitation on beach rock (62.0%), and adjusted rates of mortality were twice as high on the windward south coast as on the north coast and 3 times that on the west coast. Annual natural mortality, conservatively reported at 16–30 females per year, claims an estimated 0.3%–1.0% of the annual adult female nesting population at Aldabra, which is otherwise healthy, increasing, and free of terrestrial predation.

There is a paucity of information on the presence and nesting of green turtles, Chelonia mydas, in Kuwait, and known nesting habitats have been altered in recent years. Through beach monitoring and satellite telemetry, we determined that green turtle nesting is now limited to Qaru Island with 1–5 turtles nesting annually and that foraging habitats occur along the northern shore of Failaka Island (n  =  2 turtles) and coastal region of central Saudi Arabia (n  =  1 turtle). Foraging habitat in Kuwait overlaps with a coastal trap-fishery, raising concerns for the conservation of this depleted population.

Six sites that were sampled for alligator snapping turtles in 1993–1994 were resampled in 2009 at the same locations where previous researchers trapped. Significantly fewer alligator snapping turtles were captured per trap night at all 6 sites, and the population structure of the alligator snapping turtles had a significantly different distribution in 2009 compared with 1993–1994. In order to continue monitoring their long-term trends in relative abundance and population structure, future sampling of alligator snapping turtles at these 6 sites is recommended.

A phylogenetic analysis of partial sequences of 2 mitochondrial genes, NADH dehydrogenase subunit 4 (ND4) and cytochrome b (cyt b), supports the generic distinction and sister taxon relationship of Platemys and a monophyletic Acanthochelys. Acanthochelys radiolata is the most distinct member of the genus Acanthochelys and is sister to a clade that includes A. spixii, A. pallidipectoris, and A. macrocephala. Parsimony and maximum likelihood analyses suggested A. spixii (A. pallidipectoris, A. macrocephala), but this was not strongly supported in bootstrap analysis parsimony and maximum likelihood analyses and low Bayesian posterior probabilities. Evidence of molecular diversity within morphologically defined species suggests that there may be additional cryptic species in this group.

We conducted an experiment using freshwater painted turtles (Chrysemys picta) to determine if keeping turtles out of water for an hour enhances anoxia recovery following a simulated bycatch event in nets (i.e., 12 hrs of submergence at 25°C). Traditional blood physiology measures and the novel application of a reflex impairment index (e.g., responses to gravity, light, and tactile stimuli) indicated that keeping turtles in or out of water for an hour did not yield a significant improvement in anoxia recovery; however, when the majority of reflexes are impaired, in particular the tactile response (e.g., limb movements), it appears that assisted recovery (keeping turtles out of water) can reduce the chance of postrelease mortality. The use of the reflex impairment index is a simple and inexpensive way to determine turtle bycatch condition after submergence in nets and discern whether assisted recovery may be required.

Exhaustive interview surveys were carried out on the upper Red River (Honghe) and nearby river systems of southwest China to characterize the distribution of Rafetus swinhoei, one of the rarest turtles in the world. The results show that the species once ranged strictly in the Red River system, apart from the lower Yangtze, and still existed in recent years, although it was on the brink of extinction due to overharvesting and habitat degradation. Further conservation efforts require monitoring of the hunting and trade of turtles in this region, public education, delaying the building of dams, setting up new protected areas, and international cooperation.

The keeled box turtle, Cuora mouhotii, is documented in southern Vietnam for the first time, extending the range of the species approximately 300 km southward. The southern population is morphologically similar to the subspecies C. m. obsti and occurs in sympatry with Cuora picturata, a species recently discovered in the wild for the first time. As C. mouhotii is known to hybridize with the closest living relatives of C. picturata (Cuora galbinifrons and Cuora bourreti), this finding allows for the possibility, on the basis of geography, that C. mouhotii and C. picturata may also hybridize in the wild.

Sexual dichromatism is common in many animal taxa, but little quantitative information on sexual dichromatism is available for turtles. We quantified sexual dichromatism in the postorbital spots of northern map turtles (Graptemys geographica) using reflectance spectrometry and examined the relationship between postorbital spot coloration and circulating testosterone among males. We found that the coloration of postorbital spots differs between the sexes, with adult males exhibiting brighter spots than adult females. However, adult males and juvenile females did not exibit siginficant differences in coloration, and testosterone levels did not explain the variation in postorbital spot coloration among males.

We quantified basking site usage by native western pond turtles (Emys [ =  Actinemys] marmorata) and introduced red-eared sliders (Trachemys scripta elegans) in an urbanized waterway. A lower frequency of human disturbance, steeper slopes, shallower water adjacent to basking sites, and a concrete substrate were all associated with a higher abundance of native threatened pond turtles relative to introduced sliders. These differences suggest new habitat management practices that could favor native pond turtles in the face of competition from invasive sliders.

Little is known about the movement behavior of the stripe-necked musk turtle, Sternotherus minor peltifer. Using radiotelemetry, we calculated mean (± SD) home range length, which was 341.4 ± 90.3 m, with home range length not differing between the sexes (males, 335 ± 194 m; females, 346 ± 79.5 m). Sternotherus m. peltifer were active in every month of the year but decreased their movement distance and frequency between December and March; during nonwinter and winter periods, individuals used limestone bluffs most often.

The goal of this project was to carry out surveys in northern and central México to locate extant populations of Kinosternon hirtipes chapalaense, K. h. magdalense, and K. h. megacephalum, evaluate their conservation status, help establish captive breeding colonies of these taxa in the near future, and collect tissues for phylogenetic studies. During 2010 and 2011, we were able to locate extant populations of 2 of the subspecies (K. h. chapalaense and K. h. magdalense), but K. h. megacephalum could not be found. We also failed to locate natural springs in a radius of approximately 60 km from the type locality (and only known locality) of K. h. megacephalum and believe that this turtle is extinct.