Showing papers in "Chelonian Conservation and Biology in 2018"

Global conservation status of turtles and tortoises (order Testudines)

Abstract: We present a review and analysis of the conservation status and International Union for Conservation of Nature (IUCN) threat categories of all 360 currently recognized species of extant and recently extinct turtles and tortoises (Order Testudines). Our analysis is based on the 2018 IUCN Red List status of 251 listed species, augmented by provisional Red List assessments by the IUCN Tortoise and Freshwater Turtle Specialist Group (TFTSG) of 109 currently unlisted species of tortoises and freshwater turtles, as well as re-assessments of several outdated IUCN Red List assessments. Of all recognized species of turtles and tortoises, this combined analysis indicates that 20.0% are Critically Endangered (CR), 35.3% are Critically Endangered or Endangered (CR+EN), and 51.9% are Threatened (CR+EN+Vulnerable). Adjusting for the potential threat levels of Data Deficient (DD) species indicates that 56.3% of all data-sufficient species are Threatened. We calculated percentages of imperiled species and modifi...

The Role of Sand Moisture in Shaping Loggerhead Sea Turtle (Caretta caretta) Neonate Growth in Southeast Florida

Abstract: Many environmental variables that affect incubating turtle eggs in the nest may also affect hatchling development, following hatchling emergence. However, these effects may be subtle and are largely unexamined. In this study, we analyzed the effect of sand moisture content during incubation on the postemergence growth rates of loggerhead sea turtles (Caretta caretta) in southeastern Florida. We divided 10 clutches in halves, reburied them, and exposed them to 1 of 2 treatments. At emergence, 7 clutches met minimum criteria for inclusion in the study. One halfclutch received only ambient rainfall (“dry” treatment) while the other half-clutch received ambient rainfall plus daily watering (“wet” treatment). Data loggers were used to record incubation temperatures in both groups. Hatchlings were captured at emergence and laboratoryreared over a period of ∼ 3 mo. Mass, straight carapace length (SCL), and straight carapace width (SCW) were measured weekly to track growth. Initial measurements were larger for turtles from the wet nests in all metrics. Turtles from wet nests grew more in SCW than turtles from dry nests. Turtle growth from the 2 treatments did not differ in SCL or mass measurements. Larger initial sizes and faster SCW growth may enable the turtles to more quickly achieve a refuge size from their gape-limited predators. Moisture availability during nesting season is projected to decrease based on climate change models. If that change materializes, it could negatively affect hatchling sizes and neonate growth rates, survival, and hence the recovery of this imperiled species.

Marine turtle presence in the traditional pharmacopoeia, cosmovision, and beliefs of Wayuú indigenous people

Abstract: Marine turtles are considered by people of several cultures to be a gift from God. This belief often leads to the use of these reptiles in the traditional and belief systems among aboriginal peoples. Certainly this is the case among Wayuu people, who are an indigenous group settled between Venezuela and Colombia, in the Guajira Peninsula. To assess the value of marine turtles to Wayuu ancestral people, especially as a medicinal resource, we carried out a comprehensive open-ended question-based survey of traditional healers and caretakers (locally known as Piaches and Outsus) from 4 Wayuu communities in the Venezuelan portion of the Guajira Peninsula. We documented customary practices where marine turtles' body parts are used as a key element of the remedies. Eleven marine turtle body parts were identified by respondents as remedies used by Wayuu people, with 7 different ways to administer them (drink, worn, powder, among others). Four of the 5 species of marine turtles present in Venezuelan waters were identified as being used in the traditional pharmacopoeia of Wayuu people; their traditional names are included on this article. Some considerations about the Wayuu's cosmovision, customs, traditions, and belief systems are included here. Our results are important in the context of likely future evaluation of the current Venezuelan legal framework to consider inclusion of traditional use of marine turtles in Venezuela. Abstract [Spanish] Las tortugas marinas son consideradas por diversas culturas como un regalo proveniente de Dios. Es en esta creencia en la que usualmente se basan las tradiciones y costumbres de numerosas comunidades indigenas que utilizan a estos reptiles a nivel global. Ciertamente, este es el caso de los indigenas Wayuu, grupo el cual se encuentra asentado entre Colombia y Venezuela, en la Peninsula de la Guajira. Se realizo una valoracion ancestral de las tortugas marinas para los indigenas Wayuu, con especial enfasis en los usos medicinales, se llevaron a cabo una evaluacion comprensiva y exhaustiva, la cual incluyo entrevistas y encuestas con preguntas abiertas, a pobladores Wayuu con amplio conocimiento sobre las practicas medicinales tradicionales (conocidos localmente como Piaches y Outsus) en comunidades localizadas en la porcion venezolana de la Peninsula de la Guajira (territorio ancestral Wayuu). Se documentaron las practicas y costumbres en las que diversas partes del cuerpo de la tortuga marina juegan un papel primordial en la creacion y aplicacion de estos remedios tradicionales. Los entrevistados identificaron hasta once diferentes partes del cuerpo de la tortuga marina que son utilizados en la elaboracion de remedios, asi como siete diferentes formas de administracion de la medicina (tomada, untada, granulada, entre otros). Cuatro de las cinco especies de tortugas marinas presentes en las aguas territoriales venezolanas fueron identificadas como parte importante de la farmacopea tradicional de los indigenas Wayuu, en este articulo se incluyen los nombres tradicionales en Wayuunaikii de estos reptiles. Asi mismo, en la presente investigacion se mencionan algunas consideraciones sobre la cosmovision, costumbres, tradiciones y creencias Wayuu. Estos resultados son importantes en el contexto de una posible futura revision del marco ambiental legal venezolano para considerar una posible inclusion de estos usos tradicionales de tortugas marinas en Venezuela.

Did Declining Carrying Capacity for the Kemp's Ridley Sea Turtle Population Within the Gulf of Mexico Contribute to the Nesting Setback in 2010−2017?

Abstract: The Kemp's ridley (Lepidochelys kempii) is the most endangered sea turtle species. During 1966–2017, an annual count of nests (i.e., clutches of eggs laid) has served as an annual index of Kemp's ridley nesting female abundance on the Gulf of Mexico (GoM) index beach in Tamaulipas, Mexico. This index was increasing exponentially at 19% per year in 2009, but it dropped unexpectedly by more than a third in 2010 and through 2017 remained well below levels predicted. We hypothesize that pre-2010 declining carrying capacity for the Kemp's ridley population within the GoM contributed to this nesting setback. We discuss pre-2010 factors that may have caused carrying capacity to decline, including degradation of the GoM ecosystem, the exponentially increasing Kemp's ridley population, and declining per capita availability of neritic (i.e., postpelagic) Kemp's ridley food, including natural prey and scavenged discarded bycatch from shrimp trawling. We encourage evaluations (especially those within a robus...

A Distinctive New Species of Mud Turtle from Western México

Abstract: The genus Kinosternon in Mexico is represented by 12 species of which only 2 inhabit the lowlands of the central Pacific region (Kinosternon chimalhuaca and Kinosternon integrum). Based on 15 standard morphological attributes and coloration patterns of 9 individuals, we describe a new microendemic mud turtle species from the central Pacific versant of Mexico. The suite of morphological traits exhibited by Kinosternon sp. nov. clearly differentiates it from other species within the genus Kinosternon by a combination of proportions of plastron and carapace scutes, body size, and a large yellow rostral shield in males. The new species inhabits small streams and ponds in and near the city of Puerto Vallarta, Jalisco. Unfortunately, natural populations are unknown so far. The habitat is damaged by urban growth, and only one female is known. The available information would suggest that Kinosternon vogti sp. nov., is one of the most threatened freshwater turtle species. An urgent conservation program is...

Potential for Relocation to Alter the Incubation Environment and Productivity of Sea Turtle Nests in the Northern Gulf of Mexico

Abstract: Sea turtle nest relocation is a management strategy commonly used to mitigate hatchling mortality, particularly that due to wave wash-over and tidal groundwater inundation. Relocation can alter the incubation environment, so there is concern regarding potential modifications to embryonic development. Several studies have explored the effects of relocation on nest productivity; however, these studies often only compare reproductive output and incubation environments between relocated and in situ nests without accounting for the incubating environment of the original nest location. We assessed the differences in sand temperature, inundation exposure, grain size, and moisture content between the original and final locations of relocated nests at a loggerhead (Caretta caretta) nesting beach in Fort Morgan, Alabama, as well as differences in nest productivity between in situ and relocated nests. Differences in mean sand temperature, likelihood of inundation, and sand moisture between original–relocated locations and in situ–relocated nests were not significant. Emergence success was significantly lower in relocated vs. in situ nests, and sand grain distributions were significantly different between original and relocated nest locations. Given that relocation did not improve nest productivity nor reduce the likelihood of inundation, this practice conferred minimal net benefit to sea turtle nests on dissipative-to-intermediate beach conditions typical of the northern Gulf of Mexico. To improve the justification for nest relocation under these beach conditions, a better understanding of embryonic tolerance to inundation and clarification of relocation criteria and guidelines is required.

Factors Affecting Nesting Ecology of Apalone spinifera in a Northwestern Great Plains River of the United States

Abstract: The nesting ecology of Apalone spinifera in large North American rivers is largely unknown despite the wide distribution of the species in these naturally dynamic ecosystems. We describe the nesting locations, timing, behavior, and habitat of A. spinifera in relation to natural and anthropogenic factors in the Missouri River. Nesting followed annual peak river stage, mostly occurred in the afternoon when air temperatures were 25°–30°C, and did not occur when human activity was nearby. Apalone spinifera nested in June in a year with average discharge (2012), but nested 20 d later in a year with a large flood event (2011). During the average discharge year, 90% of nests were found on islands, but similar proportions of nests were found on island and mainland habitats during the flood year because many islands were inundated. Nests were mostly in mixed-gravel substrates where vegetation cover was sparse or absent. Depredation occurred only after the emergence of hatchlings (∼ 60 d after nesting) and...

Development and Validation of an Environmental DNA Method for Detection of the Alligator Snapping Turtle (Macrochelys temminckii)

Abstract: The alligator snapping turtle (Macrochelys temminckii) is under consideration for listing as a federally endangered species. Distributional data and estimates of population sizes are needed to make a sound decision regarding listing, but this information is largely unavailable due to the immense effort required for M. temminckii trapping surveys. To alleviate difficulty in detection and to help inform subsequent field-intensive survey efforts, we developed an environmental DNA (eDNA) method capable of providing presence data even in systems with high turbidity and suspended organic material. The assay we developed utilizes probe-based quantitative polymerase chain reaction and reliably amplifies M. temminckii eDNA in both lentic and lotic systems, with no amplification observed in other nontarget, sympatric turtle species. The novel eDNA method developed, optimized, and field-tested in this study provides a promising tool for detection of alligator snapping turtles, with resultant presence data likely to prove beneficial for the management and conservation of this species.

Space Use of Yellow-Spotted River Turtles (Podocnemis unifilis) in Yasuni National Park, Ecuador

Abstract: The yellow-spotted river turtle (Podocnemis unifilis) plays ecological roles in the Amazonian aquatic ecosystem and has cultural and economic significance for indigenous peoples. Because spatial ecology and movement data are nonexistent for this species, we radio tracked 63 individuals in the Napo River between August 2015 and February 2017. Mean linear range size was 16.2 km (n = 31) and mean home range size was 5.2 km2 (n = 27). Our results are the first range size estimates for P. unifilis and suggest that the species could be treated as a short-distance facultative migrant with local seasonal movements.

Identification of Potential Sea Turtle Bycatch Hotspots Using a Spatially Explicit Approach in the Yucatan Peninsula, Mexico

Abstract: A spatially explicit participatory approach was used to collect fishing effort and sea turtle bycatch data from local fishers at 15 ports in the Yucatan Peninsula, Mexico. These data were combined with satellite telemetry data to define potential bycatch hotspots. This is the first participatory and spatially explicit study on sea turtle bycatch rates in the region. Hawksbill turtles (Eretmochelys imbricata) were the most frequently caught bycatch species, followed by loggerheads (Caretta caretta) and green turtles (Chelonia mydas). Gillnets were the most dangerous for sea turtles, with the greatest incidence of dead turtles caught. Three particular bycatch hotspots were identified at the northeast, northwest, and southwest coasts of the peninsula. Identification of bycatch hotspots is recognized worldwide as a key element for protecting these endangered species, particularly in a region such as the Yucatan Peninsula that harbors critical habitats for ≥ 4 sea turtle species, 2 of them categorized...

Status of Olive Ridley Sea Turtles (Lepidochelys olivacea) After 29 Years of Nesting Rookery Conservation in Nayarit and Bahía de Banderas, Mexico

Abstract: Olive ridleys (Lepidochelys olivacea) are the most numerous sea turtle species worldwide and also locally along the Pacific coast of Mexico. Published data on their distribution and nesting abundance along the coast of Nayarit and northern Jalisco, Mexico are, however, scarce. Here we describe the current extent of conservation activities and the history of efforts to protect sea turtles along this 394-km stretch of coastline. We found that 110 km (of the total of 394 km) are monitored by 18 sea turtle conservation programs, which in 2015 accounted for 43.2% of the total shoreline. Olive ridley sea turtle nesting was encountered on all monitored beaches. Our use of hatchery-protected nests as a measure of nesting levels is undoubtedly an underestimate of overall nesting in the region; however, it nevertheless provides a baseline of current nesting intensity in sites under conservation. Bahia de Banderas presented the highest nesting levels in the study area with 46.4% (3742 ± 904; mean ± SD) of t...

Natural Beach Vegetation Coverage and Type Influence the Nesting Habitat of Hawksbill Turtles (Eretmochelys imbricata) in Campeche, Mexico

Abstract: The hawksbill turtle (Eretmochelys imbricata) is a critically endangered species with a global distribution and is broadly distributed along the Yucatan Peninsula in the Gulf of Mexico. To complete its life cycle, this species uses sandy beaches with particular environmental conditions that facilitate nesting and hatching. This study aimed to identify if beach physical characteristics influence biological reproductive parameters (hatching and emergence success). Nesting activity was monitored along 18 km of beach in the state of Campeche, Mexico, during 2014. Seventy-eight nests were recorded, 12 physical and environmental variables were measured in the nests and contiguous areas, and the hatching and emergence success of each nest was determined. Beach slope and width had no significant relationship to nest site selection. Nest depth and nest distance to highest tide and vegetation, including vegetation type, did influence hatching and emergence success. Herbaceous and bushy plants were positive...

Morphometric Models of Growth in Ornate Box Turtles (Terrapene ornata ornata) as Related to Growth Rings

Abstract: Few studies document early growth of hatchling turtles. We fit growth models to 606 carapace length (CL) measurements of ornate box turtles (Terrapene ornata ornata) for 231 males, 226 females, and 53 individuals of undetermined sex. We used the Richards model to fit 95% confidence bands and 95% prediction bands on the best-fit curves for males and females. We also computed Spearman's rho correlation relating growth ring counts to CL and plotted change in CL for 131 recaptured individuals (45 males, 57 females, and 29 individuals of undetermined sex) for which we had two or more measurements from different years. There was a strong correlation between CL and number of growth rings. Using the properties of the derivative of Richards growth model, juvenile 1, juvenile 2, subadult, and adult stages were defined for male and female growth. Our overall growth models were similar to those for studies of ornate box turtles in Kansas and South Dakota and the desert box turtle (T. o. luteola) in New Mexico; however, our growth stages were defined by smaller turtles. Unlike a previous study in South Dakota, our adult males were larger than adult females. Prior to a CL of approximately 86 mm and 8 growth rings, the carapace grew faster than the plastron, after which the plastron grew faster than the carapace. Five hatchlings' plastra grew an average of 26% (SD = 14%) the first year and the carapace grew an average of 15% (SD = 7%). During the first 3 yrs, most individuals developed only one growth ring per year. If major growth rings approximate age, size can be used to estimate age in ornate box turtles up to 60–90 mm (about 8 growth rings). Between 8 and 12 growth rings, size and age are also correlated, but accuracy of age estimates decreases. Life-history traits such as age at reproductive maturation and size at which individuals are vulnerable to predation are important to assess long-term viability of a population; therefore, understanding environmental impacts on individual growth is important for conservation planning and management of this threatened species in Iowa.

Movements of Green Turtles (Chelonia mydas) Rescued from Pound Nets Near Jeju Island, Republic of Korea

Abstract: Green turtles (Chelonia mydas) are observed year-round in the Sea of Jeju Island, Republic of Korea; however, there is limited information on their migration and seasonal distribution outside of Korean waters. To investigate their spatial and temporal movement, we tracked 8 green turtles (straight carapace length range, 49.7–85.9 cm; mean ± SD, 63.36 ± 10.99 cm), taken as bycatch in pound nets near Jeju Island, using satellite transmitters from August 2015 to January 2017. Turtles were mainly juveniles and were tracked for 17–314 d. Three turtles traveled more than 400 km from their release site in 2 different directions: one individual moved westward to China within 17 d of release, and 2 individuals traveled eastward to Japan. One turtle that moved to Japan had been flipper-tagged at Kagoshima, Japan, 1 mo prior to its capture at Jeju Island. The other 5 individuals remained near the coast of Jeju Island. The individual tracked for the longest period (314 d) overwintered (water temperature, 12°–14°C) in the eastern area of Jeju Island. These results indicate that green turtles from different regions, including China and Japan, may use the areas around Jeju Island for foraging, for overwintering, and/or as a migratory corridor. To fortify the conservation of green turtles in the region, international cooperation and expanded research efforts, such as genetic studies, are needed.

Importance of Sand Particle Size and Temperature for Nesting Success of Green Turtles in Penang Island, Malaysia

Abstract: The microhabitats of green turtle (Chelonia mydas) nests were investigated to identify key factors influencing nesting success by monitoring both successful nests (n = 43) and aborted nests (n = 106) created by the same individuals (n = 9) from September 2013 to September 2014 on Penang Island, Malaysia. The effect of sand particle size on nesting success was significant, suggesting that green turtles tend to abort nesting at sites with sands of particle sizes < 1 mm. In addition, nests were successful at superficial sand temperatures less than 32.95°C.

Green Turtles Nesting at Their Northern Range Limit in the United States Represent a Distinct Subpopulation

Abstract: Green turtle nesting has been recorded in North Carolina, since 1980, but how these nesting females fit into the broader regional context genetically has not been determined. Genetic tagging through microsatellite genotyping of clutches laid in northern South Carolina, North Carolina, and Delaware from 2010 through 2014 identified at least 52 individual nesting females. The mitochondrial control region haplotype frequencies of these individuals were significantly different from all northern Greater Caribbean subpopulations, including those in Florida, suggesting that these northern US females represent an incipient subpopulation that warrants distinct management unit status.

Origin and Structure of a Large Aggregation of Suwannee Cooters (Pseudemys concinna suwanniensis) in a Florida Spring

Abstract: Animals aggregate to reduce predation risk, facilitate mating, and access resources with patchy distributions. During a long-term study of turtle populations in the Santa Fe River (SFR) ecosystem in northern Florida, we observed a large aggregation of turtles at Gilchrist Blue Springs Park (GBSP) in August–October 2013 and again in March–May 2014. On 8 September 2013, we hand-captured 496 turtles of 5 species in GBSP. The Suwannee cooter (Pseudemys concinna suwanniensis) was the most abundant species in the sample, with 477 individuals representing all demographic groups. Density of this species was 530 turtles/ha and biomass was 2242 kg/ha. We hypothesize that hydrological changes in the SFR basin contributed to the temporary turtle aggregations at GBSP. The 113-km SFR originates as a tannin-stained blackwater stream, but receives input of clear water from ≥ 45 artesian springs in its lower 37 km. Heavy rainfall in the upper SFR basin from Tropical Storm Debby in June 2012 resulted in a large in...

Relative abundance of invasive red-eared sliders (Trachemys scripta elegans) and native western pond turtles (Emys marmorata) at Clear Lake, Lake County, California.

Abstract: During 2010–2018 we studied the relative abundance of invasive red-eared sliders (Trachemys scripta elegans) and native western pond turtles (Emys marmorata) at Clear Lake and its associat...

Ecological Observations of the Mexican Mud Turtle (Kinosternon integrum) in the Pátzcuaro Basin, Michoacán, México

Abstract: Capture–mark–recapture and radiotelemetry was used in a population of the Mexican mud turtle (Kinosternon integrum) in the Patzcuaro Basin. Calculated population size was 60 individuals. Sex ratio was skewed to females (1:4.75). Home range of the tracked females ranged from 0.08 to 2.7 ha and indicates a high fidelity with their aquatic and terrestrial microhabitats.

Lights On, or Lights Off? Hotel Guests' Response to Nonpersonal Educational Outreach Designed to Protect Nesting Sea Turtles

Abstract: Light pollution from beachfront hotels has the potential to impact nesting and hatching sea turtles. Education strategies could be used to alter visitor behavior and mitigate this threat. We tested the efficacy of a sea turtle–friendly education card that encouraged visitors to “protect the night, hide the light.” Cards were placed in beachfront hotel rooms at a prominent sea turtle nesting site: Jekyll Island, Georgia. We assessed visitor responses by conducting nightly observations to determine the proportion of occupied guest rooms with beach-visible lights under 2 different scenarios (cards present or cards absent). We found that less than half of all hotel guests closed room blinds to minimize artificial light on the nesting beach, and compliance rates seemed to be lower during peak visitation times. The nonpersonal educational treatment (card) had little effect on visitors' sea turtle–friendly lighting choices and behaviors, highlighting the need for other approaches to encourage responsible tourist behavior at ecologically sensitive beach destinations.

Genetic Differentiation of Hawksbill Turtle Rookeries on St. Croix, US Virgin Islands

Abstract: We collected tissue samples from 41 nesting hawksbill turtles (Eretmochelys imbricata) at Sandy Point National Wildlife Refuge, St. Croix, US Virgin Islands, to characterize the genetic structure of this rookery in terms of mitochondrial DNA; we compared haplotype frequencies from this rookery to those from Buck Island, another hawksbill nesting beach on St. Croix. Pairwise FST comparisons showed that Sandy Point was demographically distinct from Buck Island (FST = 0.501, p < 0.001), a finding reinforced by significantly different haplotype frequencies (χ2 = 51.76, p < 0.001) and a lack of interchange of nesting females between both sites based on mark–recapture data. Our results support the delineation of the nesting populations at Sandy Point and Buck Island into separate units for the purposes of management.

Movements of Olive Ridley Turtles (Lepidochelys olivacea) in the Bay of Bengal, India, Determined via Satellite Telemetry

Abstract: The migratory movements of 14 olive ridley turtles (Lepidochelys olivacea) in the Bay of Bengal were studied using satellite telemetry during 2009–2010. Tracking data show that olive ridley turtles undertake open-ocean migrations in the bay and exhibit migratory corridor between foraging habitat of Sri Lanka and nesting sites along the Odisha coast of India. Tracking durations ranged 7–331 d (mean = 151 ± 95.9 d). The tracked turtles had a mean traveling speed of 2.49 ± 0.02 km/hr and moved an average of 31.7 km/d, remaining within a mean distance of 163.28 ± 50.9 km (range, 1–535 km) from the east coast of India. Turtles occupied waters with sea surface temperature (SST) ranging from 24°C to 31°C with chlorophyll concentrations of 0 to 3.9 mg/m3. Our study confirms that olive ridley turtles in the Bay of Bengal move within a broad range of SSTs and chlorophyll a concentrations; no correlation was found between turtle movements and these 2 oceanographic parameters (r2 = 0.02, n = 77). Our data in...

An Examination of the Accuracy of Using Plastral Scute Rings to Age Spotted Turtles (Clemmys guttata)

Abstract: The use of plastral scute rings to age turtles is a widely practiced technique, but a lack of rigorous field testing of this method has led to critiques of its usefulness and accuracy. We tested the method's effectiveness for aging spotted turtles (Clemmys guttata) by calculating an Age-Increase Ratio and by recording changes in the number of scutes within a year. We found no correlation between the change in the number of scute rings and the number of years between captures, which likely stems from the observer error associated with the difficulty of accurately counting scutes on older turtles; however, we did record a significant correlation between the number of scute rings and body size.

Comparisons of Summer and Winter Patterns in Ovarian Development, Plasma Vitellogenin, and Sex Steroids in Female Diamondback Terrapins (Malaclemys terrapin) in Southern Florida

Abstract: . – The reproductive cycles of turtles are linked to environmental factors, such as photoperiod and temperature. Currently, the reproductive physiology of diamondback terrapins (Malaclemys ...

Identifying Assemblages of River Turtles Using a Passive and Systematic Capture Technique in the Mary River, Queensland, Australia

Abstract: Understanding the significance of a river reach to a particular species is critical for informing riverine restoration and management. Generally, the relative significance of a river reach for freshwater turtles is based upon population counts. However, capture rates can be greatly influenced by the methods employed, species behavior, localized in-stream conditions, and the operator's knowledge and skill. Here, we report on abundance shifts within freshwater turtle assemblages along a river continuum using a protocol that standardized the sampling effort. Turtle capture was undertaken at 20 study sites along the Mary River (Queensland, Australia), and repeated identically every 6 mo over a 2-yr period. A large funnel trap with a 30-m wingspan was deployed at each site and turtles were captured over a 4-d period. The turtle species assemblages significantly differed between the upper, mid, and lower catchments (multivariate analysis of variance, p < 0.05), suggesting species preference for the broad geomorphological and ecological features of each reach. The observed spatial variance in species assemblage was consistent over time and unaffected by the season, demonstrating that the assessment was repeatable and unaffected by individual species' life history patterns. We argue that trends in turtle species assemblage could be used instead of absolute species count data to alert natural resource managers to shifts in conditions and provide early warning signs of habitat degradation or management success. The technique is cheaper and easier to implement than abundance counts and ensures that capture biases remain constant under different conditions and operators.

Sea Turtle Education Program Development, Implementation, and Outcome Assessment in St. Kitts, West Indies

Abstract: To address some of the threats facing sea turtles in St. Kitts, the St. Kitts Sea Turtle Monitoring Network (SKSTMN) has implemented a number of conservation education programs. The primary conservation education program has been an annual Sea Turtle Camp Program that was developed and initiated in 2007 with the goal of engaging and educating youth in the conservation of sea turtle species. In 2015 and 2016, the SKSTMN performed an assessment of this education program. The outcome assessment included 1) evaluation of pre- and postparticipation tests for the 2015 and 2016 participants, 2) comparison with a control group of nonparticipants who took the posttest, and 3) a survey of former participants and their parents or guardians. The pre/post exercise was performed to determine if students were gaining and retaining information during the Sea Turtle Camp Program and if participants had a stronger knowledge base than nonparticipants. The survey of former participants was performed to determine if this program had positively affected participants and their perceptions regarding sea turtles, the marine environment, and conservation; to ascertain strengths and weaknesses of the Sea Turtle Camp Program; and to identify conservation education areas that could be further developed. The results obtained for participants in the Sea Turtle Camp Program between the pre- and posttests indicated that the educational modalities used are successfully relaying the desired information and that the majority of the participants are retaining this information throughout the Sea Turtle Camp Program. Additionally, the results on the pre- and posttests for the Sea Turtle Camp Program participant group vs. the control group of nonparticipants indicate that the Program had a significant impact on participants' knowledge regarding sea turtle natural history, biology, and St. Kitts–specific sea turtle issues. Findings indicated that there were positive changes in behavior toward the marine environment and sea turtles in Sea Turtle Camp participants following participation and that there was a need for additional curriculum to be developed to accommodate former participants who were interested in continuing their participation in the program.

Crowding Affects Health, Growth, and Behavior in Headstart Pens for Agassiz's Desert Tortoise

Abstract: Worldwide, scientists have headstarted threatened and endangered reptiles to augment depleted populations. Not all efforts have been successful. For the threatened Agassiz's desert tortoise (Gopherus agassizii), one challenge to recovery is poor recruitment of juveniles into adult populations, and this is being addressed through headstart programs. We evaluated 8 cohorts of juvenile desert tortoises from 1 to 8 yrs old in a headstart program at Edwards Air Force Base, California, for health, behavior, and growth. We also examined capacities of the headstart pens. Of 148 juveniles evaluated for health, 99.3% were below a prime condition index; 14.9% were lethargic and unresponsive; 59.5% had protruding spinal columns and associated concave scutes; 29.1% had evidence of ant bites; and 14.2% had moderate to severe injuries to limbs or shell. Lifetime growth rates for juveniles 1–8 yrs of age were approximately two times less than growth rates reported for wild populations. Tortoises in older cohorts...

Effectiveness of Concealed Nest Protection Screens Against Domestic Predators for Green (Chelonia mydas) and Hawksbill (Eretmochelys imbricata) Sea Turtles

Abstract: Mammalian depredation of nests has been listed amongst the most significant threats to hatchling success in sea turtles. In 2013, at least 13% of green turtle (Chelonia mydas) and 25% of hawksbill turtle (Eretmochelys imbricata) nests were lost to domestic dog predation on Playa Norte, Costa Rica. In 2014 and 2015, plastic and bamboo protective screens were deployed to protect nests. Screens were deployed at different stages of the incubation period and the success of the nests analyzed. Predation rates increased as the seasons progressed with October and November being the peak depredation months, as well as the peak for hatchling emergences. Eggs remaining in nests that had been partially depredated had a significantly lower percentage of hatching success than eggs in undisturbed nests. There was no significant difference between timing of deployment and likelihood of a screen being breached. The likelihood of a screen being breached was highly dependent on the type of material used; bamboo screens were ca. 153% more effective than plastic and successfully prevented the complete predation of ca. 48% of nests. Bamboo screening is an inexpensive, environmentally inert, yet labor-intensive method for reducing nest depredation by domestic dogs. This screening method does not impact the hatching or emerging success of the nest.

Chelonian Predation by Jaguars (Panthera onca)

Abstract: We present a new record of freshwater turtle predation by the jaguar, Panthera onca, in addition to a current review of chelonian predation by this feline. In total, 16 species of chelonia...

Discovery of a Major East Pacific Green Turtle (Chelonia mydas) Nesting Population in Northwest Costa Rica

Abstract: Here we report on a newly discovered nesting population of east Pacific green turtles (Chelonia mydas) in northwest Costa Rica at San Jose Island, Murcielago Archipelago, that rivals those...