The olive ridley sea turtle (Lepidochelys olivacea), a species listed by the International Union for Conservation of Nature as vulnerable, is characterized by its mass-nesting behavior, also known as arribada. For decades, this phenomenon has facilitated the utilization of this species by coastal communities, much of it illegally. At Ostional beach, Costa Rica, a community-based egg-harvest program operates legally to generate important income for the community while promoting the protection of the ridley nesting assemblage. However, to date, no analysis exists that indicates the long-term viability of the egg harvest program as a sound management tool. To address this void, we generated baseline abundance data of the major arribada events that occurred in the period 2006–2010, as well as egg harvest data, along with preliminary hatching success. Arribadas ranged between 3564 and 476,550 egg-laying females, which indicated a large variability in the magnitude of the mass nesting events. Estimated mean egg harvest was 4746.4 and ranged from 1527 to 8138 total clutches. In relation to the estimated number of clutches laid, the estimated mean of clutches harvested was 21.2%, ranging from 1.5% to 102.4%. Estimated monthly mean hatching rates ranged from 0.0% to 32.6%. It is not clear whether arribadas underwent a significant change in abundance during the study period, although the number of years covered is too short to establish a long-term trend. However, when compared with historical data, the population appears to have declined. Based on our data, we present various management recommendations aimed at increasing hatching rates.

We contrasted diets of three turtles (Elseya albagula, Myuchelys latisternum, Emydura krefftii) from free-flowing or impounded rivers in southeastern Queensland, Australia, to evaluate the effects of flow regulation. The turtle species encompassed the herbivorous, carnivorous, and omnivorous feeding guilds, respectively. The study design simultaneously considered ontogenetic dietary shifts and seasonal effects on prey availability. Relative to the river samples, diets for three turtles in impoundments were substantially reduced in prey abundance, species richness, and dietary breadth. Turtles with narrower dietary preferences in free-flowing rivers were more affected by dams than was the dietary generalist. For the most omnivorous turtle, qualitative differences were evident in diets from impoundments and rivers; yet considering its greater dietary breadth, quantitative effects on diet were minor. Diets of turtles in impoundments included fewer subaquatic plants and wind fallen fruits than did the diets of turtles in rivers. For the largely carnivorous turtle, fewer aquatic invertebrates were ingested in impoundments than in riverine habitats, and scavenging behavior was noted mainly in impoundments. Multidimensional scaling of the site characteristics identified dams or weirs with back-ups exceeding 20 km as being relatively similar in impacts on prey diversity. Canonical correspondence analysis identified factors of habitat alteration and turtle size as major determinants of underlying variance in the diets. The results suggest that turtle food webs are altered by river regulation. A general finding that turtle diets in impoundments were depleted of aquatic plants or macro-invertebrates pertains to other turtles of conservation importance.

When preparing management plans for species at risk, conservation practitioners need information on the habitat requirements of those species. In environmental extremes, the fitness of ectotherms is tightly linked to thermoregulation, as all physiological processes are temperature dependent. In an effort to better quantify the habitat requirements of Blanding's turtles (Emydoidea blandingii), a species at risk, at the northern extreme of their range, we quantified the thermoregulation patterns of adult males and gravid females during the active season. Turtles exploited their thermal environment significantly more in early season than in late season. Although basking allowed turtles to reach the highest daytime temperatures, surface water was the habitat with the highest thermal quality overall. Although not statistically significant, gravid females tended to maintain higher mean and maximum shell temperatures throughout the active season. Gravid females also spent substantially more time basking than males throughout the active season. Our results highlight the importance of stratifying field observations and thermoregulation data by reproductive class and time. Differences in behavior and thermal habitat requirements between reproductive classes and season must be considered in management plans for conservation efforts to be effective.

Despite the recognition of the historical importance of hawksbills in the Caribbean region of Honduras, prior sea turtle research in the area has been extremely limited, and little is known about hawksbill turtle (Eretmochelys imbricata) ecology from this region. We tracked 6 juvenile hawksbills (28.7–35.6 cm, straight carapace length [SCL]) with radiotelemetry off the coast of Roatán in the Bay Islands of Honduras, conducted habitat assessments at 14 sites, and examined the diet of 5 juvenile hawksbills (19.8–49.7 cm, SCL) using gastric (n  =  4) and fecal (n  =  1) samples. Home ranges of all 6 turtles were small, with 100% minimum convex polygons from 0.15 to 0.55 km², and a 50% fixed kernel density for all animals pooled of 5.46 km². The habitat assessment showed that common prey items in hawksbill diets were abundant in areas where juvenile hawksbills were resident and in nonresident areas, with sponges (Chondrilla sp., Geodia sp.) and octocorals (Pseudopterogorgia sp.) being most prevalent. We found sponge to be the primary component in the diet, comprising 59% of total ingesta. The most prevalent sponge species in the diet samples were Melophlus ruber and Chondrilla caribensis. Although C. caribensis is a common constituent of hawksbill diets, the current study provides the first report of M. ruber as a component of hawksbill diets. Home ranges of juvenile hawksbills in the Port Royal region of Roatán are small (< 1 km²), and their primary dietary component is the sponge M. ruber. Conservation efforts on Roatán should be established in the Port Royal region, and should include protection of dietary items and turtles.

Disturbances can affect the structure of ecological communities, and their impacts may have consequences for individual species' population dynamics and long-term persistence. Even without catastrophic mortality, survivorship could be reduced following a disturbance, thus leading to population decline. We used a 16-year mark–recapture dataset to determine the effects of catastrophic storms and the cutting of nonindigenous vegetation on the survivorship and abundance of a population of long-lived terrestrial turtles (Terrapene bauri). Our results indicate that these habitat disturbances had little long-term effect on abundance. Indeed, the population continued to grow despite severe changes to its habitat, although recapture probabilities decreased through time. Tertiary (adult) sex ratios became more highly skewed temporarily but eventually approached their predisturbance levels. In long-lived box turtles, short-term disturbances may alter growth rates and dispersal tendencies, but they appear to have little long-term effect on abundance as long as initial mortality is not severe and food resources remain available.

A study was conducted in 2009 to gather information on long-term gopher tortoise (Gopherus polyphemus) population dynamics, burrow distribution, and habitat use at Plum Creek/Lochloosa, a pine (Pinus elliottii; Pinus palustris) plantation in northern Florida. Mark–recapture surveys were conducted on this study site during the 1980s, and a follow-up survey was done in 1992. The ca. 66-ha study area is a mosaic of moderately well-drained and poorly drained soils, and it has had a history of clear-cutting and replanting. Recent management activities included a tree thinning in 2008 and a controlled burn in winter 2009. We located gopher tortoise burrows during late April and early May 2009, and captured tortoises in pitfall or wire traps during May–July. Fifty-two tortoises were captured on the study site and 4 others in an adjacent pine plantation across a paved rural road. Seventeen of the tortoises (33%) had been previously marked, including a male marked as a mature adult in 1982. Most (88%) marked individuals were found in the same approximate location (within 200 m) as during earlier surveys, despite the silviculture-related habitat changes over time. Only 8% of all marked (n  =  211) tortoises were recaptured in 2009. Recapture rates were 4% for tortoises marked when immature, 10% for adult males, and 21% for adult females. Drill marks held up relatively well in adult tortoises but were difficult to discern in some tortoises marked as juveniles. Size and sex class distributions of tortoises captured in 2009 were different from those observed during 1981–1987 and 1992, primarily because fewer juveniles were captured in 2009. This follow-up survey indicated that viable gopher tortoise populations can persist on sites undergoing intensive silviculture, and it further substantiated tortoise use of windrow berms, ecotones, and relatively well-drained soils.

Spatial distributions and movements of aquatic animals are typically defined by the dimensions of the aquatic system in which they live. Aquatic turtles often confound such definitions with terrestrial movements, and movements within the aquatic system remain largely undescribed. We studied the movements of adult female painted turtles (Chrysemys picta) and red-eared sliders (Trachemys scripta) in Reelfoot Lake, a large aquatic system. We determined the distance moved, home-range size, and habitat use to investigate interspecific variation, as well as the influence of habitat dimensions on turtle spatial ecology. Daily movements peaked for both species between May and August. Trachemys scripta exhibited longer movements, maintained larger home ranges, and selected deeper areas of the lake than did C. picta. Compositional analysis indicated that the shoreline habitat was used most frequently by both species, relative to its availability. However, although C. picta selected the shoreline above all other habitat types, T. scripta selected the open water areas of the lake as well. Morphological differences and dietary preferences likely explain much of the interspecific variation we observed. Turtle movements and home-range sizes we report are remarkably larger than previous estimates and may be related to the abundance of suitable habitat within Reelfoot Lake. These results demonstrate that turtle spatial ecology is strongly influenced by local environmental factors and illustrate the potential pitfalls of describing “typical” movements of aquatic turtles.

The dash of freshly emerged hatchlings to the sea is a short but critical phase in the life cycle of sea turtles. We examine the time spent on a Mediterranean beach from the perspective of substrate composition and temperature, marine debris, and hatchling crawling speeds and times. Crawling speeds depended on beach quality. The hatchlings crawled significantly faster on sand than on cobbles, and cooler temperatures considerably prolonged the crawls. Marine debris was a major impediment: hatchlings were severely entangled in fishing nets and entrapped in simple containers such as plastic cups and cut-open canisters. They never avoided contact with such experimentally deployed debris or reversed their direction to escape. The overall debris density at the study site averaged 1.03 items m⁻², mostly plastic, and 2 out of 3 hatchlings had contact with such debris on the way to the sea. Marine debris is a new aspect of habitat quality for sea turtle nesting site monitoring and conservation efforts and may help explain the long-term decline in nest numbers on this beach. This serves as a case study for the role of habitat quality in the survival of endangered species.

The destruction of prairies has led to the decline of the ornate box turtle (Terrapene ornate) across much of its range. Land management agencies are considering translocation programs to restore populations to areas from which they have been extirpated. For these conservation efforts to be successful, long-term posttranslocation monitoring is necessary to ensure that translocated individuals behave and use habitat similarly to unmanipulated individuals. We conducted a 3-yr radiotelemetry study of a potential source population of ornate box turtles to provide baseline data on home range size and site fidelity pretranslocation. Adult males and females did not differ in minimum convex polygon home range size (mean 4.0 ha), 95% fixed kernel home ranges (mean 2.6 ha), or 50% fixed kernel home ranges (mean 0.4 ha). Both sexes showed high site fidelity to annual home ranges and to previously used overwintering sites, although distance between subsequent overwintering sites was less for females than for males. At our study site, ornate box turtles have relatively small home ranges and exhibit strong site fidelity. Translocation programs for this species should closely monitor movements of translocated individuals to assess whether they are successfully establishing new home ranges or attempting to return to their site of origin. Moreover, the high site fidelity exhibited by this species suggests that newly translocated individuals may be at increased mortality risk because they are unfamiliar with suitable overwintering and/or nesting sites in their new location. The results of our study will be used to ensure that sites to which animals are translocated are comparable to the site of origin in terms of home range size requirements and important habitat features. In addition, our data serve as a critical baseline to which the habitat use and movement patterns of monitored animals posttranslocation can be directly compared to assess the success of the translocation.

We examined overwintering behavior in gopher tortoises (Gopherus polyphemus) translocated to the northern periphery of their geographic range by using miniature temperature data loggers during 2 winters. All adult and juvenile tortoises monitored with temperature loggers survived overwintering; however, during the course of the study 2 translocated juvenile tortoises without temperature loggers died during winter months. Onset and termination of overwintering were not different between the 2 yrs and were not correlated with mean above-ground air temperature. Mean overwinter duration was 127 ± 9 d SD and 128 ± 13 d SD during 2002–2003 and 2004–2005, respectively. Tortoises experienced temperatures as low as 7°C and as high as 31°C while overwintering; however, most (12 of 15) tortoises experienced very little (< 1°C) mean daily temperature fluctuation despite air temperatures regularly dropping below 0°C and exceeding 20°C. The overall mean temperature of overwintering tortoises was 12.4° ± 0.8°C (2002–2003) and 12.6° ± 1.2°C (2004–2005). Large fluctuations in temperature occurred when tortoises actively basked, and half of the monitored tortoises did, particularly juveniles, which accounted for 42% of winter basking events. Our results suggest that, given timely access to suitable refugia at recipient sites, overwinter mortality of translocated adult individuals may be minimal.

The evaluation of offspring sex ratios is important in any large-scale threatened species breeding programs if temperature-dependent sex determination is a possibility. We assessed the sex ratio in captive-bred juvenile Aldabra tortoises (Aldabrachelys gigantea or Dipsochelys dussumieri) at the La Vanille Crocodile and Tortoise Park in Mauritius. The gonads of small juvenile Aldabra tortoises are thin and elongate and fixed to the dorsal part of the body cavity, with ovaries appearing as transparent sheaths with some visible oocytes and testes appearing as small, transparent, thin, sausage-like structures with a net of fine blood vessels on the surface. With growth, ovaries expand and masses of previtellogenic follicles appear on the surface; testes first turn pinkish-white and then yellowish, with tubular structures visible through a thin, transparent theca containing a network of fine blood vessels but no melanocytes. Three tortoises had both testes and ovaries and were classified as intersexes. Aldabra tortoises bred in La Vanille in the late 1990s and 2000s show a male∶female ratio of 1∶4 (n  =  106), suggesting that Aldabra tortoises have temperature-dependent sex determination. However, the incubation conditions were not monitored rigorously enough to allow the determination of pivotal temperatures or the transitional range of male- and female-producing temperatures. Because a female-biased sex ratio seems to be preferable to a male-biased or even to a balanced sex ratio in recovery programs of threatened species, there does not seem to be an immediate need to change egg incubation methods to adjust sex ratios.

The Central American river turtle (Dermatemys mawii) is a large Critically Endangered freshwater turtle historically found in the coastal lowlands of southern Mexico, northern Guatemala, and Belize. Due to years of intense harvesting for its meat, D. mawii has been virtually eliminated from much of its former range in southern Mexico, while its status in Guatemala remains unclear. During April and May 2010, we conducted a countrywide survey in Belize to assess the current conservation status of D. mawii in what is believed to be its last stronghold. We surveyed approximately 30 localities from deep southern to extreme northern Belize, including 17 areas previously surveyed during the early 1980s and 1990s. Results indicate D. mawii is heavily depleted in most of Belize, but healthy populations remain in a few remote areas (including multiple, previously unsurveyed localities in southern Belize), especially those receiving some level of protection. While this mirrors the trend observed in previous surveys, the current findings are of particular concern because the number of localities where turtles were observed and the number of turtles observed at these localities were both much reduced compared to earlier surveys. Large turtles (reproductive adults) continue to be targeted during harvests, significantly reducing the most demographically important segment of the population. Further, interviews with fishermen and hunters indicate that laws and regulations enacted for the protection of D. mawii are largely ignored by locals, as broad-scale enforcement is difficult or impossible to achieve. In this paper, we discuss survey results in the context of previous investigations, describe levels and sources of exploitation, and provide conservation recommendations.

We examined loggerhead nest temperatures and hatchling sex ratios in an effort to more accurately predict hatchling sex ratios produced from 2 barrier islands in the northern management unit (Blackbeard Island National Wildlife Refuge and Wassaw National Wildlife Refuge, Georgia, United States) from 2000 to 2004. Temperature data loggers were placed into 169 nests to monitor incubation temperatures. Average critical period temperatures ranged from 26.3°C to 33.2°C (mean ± SE, 29.2° ± 0.1°C) and indicated seasonal variation in sex ratios. The sex of 669 hatchlings found dead in nests was histologically evaluated (n  =  212 nests; 14–90 nests/yr). The sex ratios varied from 0% to 100% female per nest (n  =  1–53 hatchlings/nest) and average sex ratio for all nests ranged from 55.5% female in 2003 to 85.4% female in 2002. In addition to monitoring nest temperature, 10 hatchlings per nest were euthanized to verify sex during 2003 on Blackbeard Island National Wildlife Refuge (n  =  10 nests) and 2004 on Wassaw National Wildlife Refuge (n  =  9 nests). Sex ratios were analyzed by using an advanced statistical program for evaluating temperature-dependent sex determination and indicated a 1∶1 temperature (temperature that produces a 1∶1 sex ratio) of 28.9°C. We offer an equation for predicting northern management unit hatchling loggerhead sex ratios by using critical period temperature and tested its validity. Sixteen of 18 nests (n  =  10 hatchlings/nest) showed no significant difference between the predicted sex ratios based on the equation vs. sex ratios obtained through histology. Our data indicated that rookery beaches north of Florida are important areas for the production and recruitments of male loggerhead hatchlings into the overall western North Atlantic Ocean and nests deposited earliest within a nesting season are primary contributors of male turtles. We suggest that nest monitoring programs grant such nests particular protection to increase their survivability and the production of hatchlings.

This study reports observations of Hawksbill sea turtles (Eretmochelys imbricata) in the Northwestern Hawaiian Islands, a remote and protected expanse of coral atolls considered outside the species range. Since no direct monitoring efforts exist, we synthesized records from historical accounts, opportunistic sightings, and internet crowdsourcing. We found 6 definitive hawksbill observations and 3 additional potential nesting records, documenting that hawksbills currently reside in the Northwestern Hawaiian Islands and suggesting that they occurred there in greater numbers historically.

The aquatic movement patterns and home-range size of the Eastern Mud Turtle, Kinosternon subrubrum, have received little attention. We radio-tracked 5 adult females and 5 adult males during 2 yrs in the Mid-Atlantic region of the United States. Our mean estimates of home-range size (18.6 ± 23 ha in 2008 and 16.3 ± 16.3 ha in 2009) and maximum aquatic distance traveled (815 ± 455 m in 2008 and 774 ± 331 m in 2009) suggest that K. subrubrum is highly adept at movement in aquatic environments.

We evaluated the diets of 81 Carolina diamondback terrapins (Malaclemys terrapin centrata) from northeastern Florida by analyzing fecal samples. Female diets were significantly different from male diets (p < 0.01); fecal samples from females contained crabs, marsh periwinkles (Littorina irrorata), and dwarf surf clams (Mulinia lateralis) in that order of occurrence, whereas fecal samples from males had dwarf surf clams and crabs in that order. We suggest that head-size dimorphism is advantageous to females during nesting forays when they experience a shift in prey availability.

We report two new localities for Trachemys dorbigni that expand the southern range border for approximately 120 km. These new localities are Arroyo Buñirigo and Arroyo Zapata. Both are streams related to the Río de La Plata shoreline at Buenos Aires province, Argentina. We also record the nonnative Trachemys scripta elegans for the first time for Argentina.

Turtle mortalities in Bahrain waters were assessed by examining carcasses and a questionnaire survey of fishermen. The evidence indicates that the shrimp trawl fishery was responsible for most of the green and loggerhead turtle mortalities; however, wire fish traps were responsible for the hawksbill and olive ridley turtle mortalities. This study provides the first record of the olive ridley turtle in Bahrain's waters.

In 2009, we repeated a freshwater turtle survey first conducted in 1976 in the Lower Rio Grande Valley (LRGV) of Texas to determine whether the abundance of freshwater turtles in the LRGV has changed over the past three decades. We captured significantly fewer red-eared sliders (Trachemys scripta elegans) and Texas spiny softshells (Apalone spinifera emoryi) in 2 recently urbanized counties (Cameron and Hidalgo), and more red-eared sliders and Texas spiny softshells in a nonurbanized county (Willacy). Land-use changes, increased urbanization, and commercial turtle harvest are likely responsible for the decline of freshwater turtles in the LRGV.

Buccal and cloacal swabs have been used for genetic sampling for a variety of reptiles but not for marine turtles to date. We evaluated whether this method offers a simple and quick way to sample cells from live marine turtles in the wild when it is not feasible to obtain blood or skin. Good-quality DNA was obtained for genetic analyses from both buccal and cloacal swabs. Although we recommend blood and skin sampling whenever possible to collect the highest quality DNA, buccal and cloacal swabs do represent a useful alternative for genetic sampling when these preferred methods are not feasible.

Nest guarding is rarely observed among reptiles. Specifically, turtles and tortoises are generally perceived as providing no nest protection once the eggs are laid. Here, we describe observations of nest guarding by female gopher tortoises (Gopherus polyphemus).