Search

Single‐visit surveys of plots are often used for estimating the abundance of species of conservation concern. Less‐than‐perfect availability and detection of individuals can bias estimates if not properly accounted for. We developed field methods and a Bayesian model that accounts for availability and detection bias during single‐visit visual plot surveys. We used simulated data to test the accuracy of the method under a realistic range of generating parameters and applied the method to Florida's east coast diamondback terrapin in the Indian River Lagoon system, where they were formerly common but have declined in recent decades. Simulations demonstrated that the method produces unbiased abundance estimates under a wide range of conditions that can be expected to occur in such surveys. Using terrapins as an example we show how to include covariates and random effects to improve estimates and learn about species‐habitat relationships. Our method requires only counting individuals during short replicate surveys rather than keeping track of individual identity and is simple to implement in a variety of point count settings when individuals may be temporarily unavailable for observation. We provide examples in R and JAGS for implementing the model and to simulate and evaluate data to validate the application of the method under other study conditions. [ABSTRACT FROM AUTHOR]

Simple Summary: River Cooters commonly occur in many freshwater ecosystems, but little is known about their growth and maturity. We used nearly 20 years of turtle tracking to estimate the growth, length at maturity, age at maturity, and sexual dimorphism of four River Cooters in five freshwater springs, four in Florida and one in Texas. We found that River Cooter juveniles grow exceptionally fast, doubling or tripling in size in the first year, while adults grow very slowly after maturing. Female River Cooters grow larger than males and mature later for the four taxa we studied but much more so for Suwannee River Cooters. Environmental differences among springs affected the growth rate of turtles more than the maximum size. Our efforts elucidate more about the life history of River Cooters and define baseline information to track potential changes to growth from natural and human disturbances in the future. Pseudemys is a genus of commonly occurring freshwater turtles with limited growth information across their long lifespans. We used 11,361 mark-recapture events to estimate the somatic growth rates of P. nelsoni, P. peninsularis, P. concinna suwanniensis, and P. texana from freshwater springs and developed a Bayesian growth model to estimate the species-specific, site-specific, and individual effects on growth. We corroborated evidence for fast juvenile growth and slower adult growth in Pseudemys but found uncommonly fast growth rates, with turtles doubling or tripling in size in the first year. P. texana males had the smallest average maximum size ( L ∞ , 243 mm), while P. c. suwanniensis females had the largest (423 mm). Environmental conditions at springs had significant effects on k , the growth coefficient, but not L ∞ . We derived, using a ratio of length at maturity to L ∞ (71.7% and 87%, males and females), that females matured 1.15–1.57 times older than males except for P. c. suwanniensis, which matured three times older. Given the local abundance declines in many Pseudemys from anthropogenic impacts, this study provides important baseline life history information for Pseudemys species for use in ongoing conservation efforts and presents a novel hierarchical modeling approach using a long-term mark-recapture dataset. [ABSTRACT FROM AUTHOR]

Citizen science is emerging as a powerful tool for the early detection of biological invasions. The exotic pet trade has been deemed as the most significant cause of establishment for reptiles, and among them, turtles have the highest number of introduction events. In Europe, at least 13 species of alien freshwater turtles have been recorded in the wild. In Greece, only two species of alien turtles have been reported, namely the American pond slider Trachemys scripta and the Florida cooter Pseudemys floridana. In this study, we provide an updated checklist of the alien freshwater turtles recorded in Greece, using citizen science, personal observations, and literature. Our results provide the first records for the country of five species, namely the Florida red-bellied cooter Pseudemys nelsoni, the Eastern river cooter Pseudemys concinna, the Chinese stripe-necked turtle Mauremys sinensis, the Chinese soft-shelled turtle Pelodiscus sinensis, and the Common snapping turtle Chelydra serpentina and new localities for T. scripta. Similar to the myth of the Lernaean Hydra (i.e., for every head chopped off, more would regrow), the pet turtle trade has been proven to have multiple heads. [ABSTRACT FROM AUTHOR]

Schiariti, J.P. and Salmon, M., 2022. Impact of Sargassum accumulations on loggerhead (Caretta caretta) hatchling recruitment in SE Florida, U.S.A. Journal of Coastal Research, 38(4), 725–734. Coconut Creek (Florida), ISSN 0749-0208. Hatchling loggerhead turtles emerge from subsurface nests on oceanic beaches at night, then crawl toward and enter the sea. Recently, increases in a floating algae (Sargassum spp.) have been reported in the mid-Atlantic and Caribbean, resulting in large accumulation on Florida's beaches. The purpose of this study was to determine if, during the 2020 nesting season, these accumulations acted as a barrier that prevented the hatchlings from crawling to the sea. Seasonal changes in Sargassum density were recorded to determine when, and under what circumstances, hatchlings could cross the accumulated wrack. There was a significant overlap between when Sargassum accumulations peaked and when the turtles emerged, with the result that during the 2020 nesting season the number of hatchlings that entered the ocean was reduced by an estimated 22%. These results suggest that algal accumulations represent a significant threat that could potentially impede the recovery of loggerhead populations that currently are either threatened or endangered, worldwide. [ABSTRACT FROM AUTHOR]

Simple Summary: In the last few decades, sea turtles have been threatened by a disease called Fibropapillomatosis. Infection causes the growth of several tumors which can prevent affected turtles from seeing, swimming, and feeding properly, often with lethal outcomes. Fibropapillomatosis was described for the first time in Florida in 1938 and has since then increased and spread worldwide. To this day, there is no strong nor clear evidence on what causes the exacerbation of this disease which is associated with a herpesvirus. There is a consensus, however, that human-driven changes in the sea turtle habitats (i.e., climate change, pollution, urbanization) might play a role in increasing the number and severity of clinical cases. This study intends to explore the role of various possible environmental drivers behind the increased occurrence of this disease. We found that sea temperature, salinity, human population density, and river discharge from the coastline could be important drivers of tumor prevalence. Results from this preliminary work have the potential to offer an important baseline for future research on environmental drivers of Fibropapillomatosis. Fibropapillomatosis is a neoplastic disease of marine turtles, with green turtles (Chelonia mydas) being the most affected species. Fibropapillomatosis causes debilitating tumor growths on soft tissues and internal organs, often with lethal consequences. Disease incidence has been increasing in the last few decades and the reason is still uncertain. The potential viral infectious agent of Fibropapillomatosis, chelonid herpesvirus 5, has been co-evolving with its sea turtle host for millions of years and no major mutation linked with increased disease occurrence has been detected. Hence, frequent outbreaks in recent decades are likely attributable to external drivers such as large-scale anthropogenic changes in the green turtle coastal marine ecosystem. This study found that variations in sea surface temperature, salinity, and nutrient effluent discharge from nearby rivers were correlated with an increased incidence of the disease, substantiating that these may be among the significant environmental drivers impacting Fibropapillomatosis prevalence. This study offers data and insight on the need to establish a baseline of environmental factors which may drive Fibropapillomatosis and its clinical exacerbation. We highlight the multifactorial nature of this disease and support the inclusion of interdisciplinary work in future Fibropapillomatosis research efforts. [ABSTRACT FROM AUTHOR]

Few aquatic animal negative-sense RNA viruses have been characterized, and their role in disease is poorly understood. Here, we describe a virus isolated from diseased freshwater turtles from a Florida farm in 2007 and from an ongoing epizootic among free-ranging populations of Florida softshell turtles (Apalone ferox), Florida red-bellied cooters (Pseudemys nelsoni), and peninsula cooters (Pseudemys peninsularis). Affected turtles presented with similar neurological signs, oral and genital ulceration, and secondary microbial infections. Microscopic lesions were most severe in the softshell turtles and included heterophilic/histiocytic meningoencephalitis, multi-organ vasculitis, and cytologic observation of leukocytic intracytoplasmic inclusions. The virus was isolated using Terrapene heart (TH-1) cells. Ultrastructurally, viral particles were round to pleomorphic and acquired an envelope with prominent surface projections by budding from the cell membrane. Viral genomes were sequenced from cDNA libraries of two nearly identical isolates and determined to be bi-segmented, with an ambisense coding arrangement. The larger segment encodes a predicted RNA-directed RNA polymerase (RdRP) and a putative zinc-binding matrix protein. The smaller segment encodes a putative nucleoprotein and an envelope glycoprotein precursor (GPC). Thus, the genome organization of this turtle virus resembles that of arenaviruses. Phylogenetic analysis shows that the RdRP of the turtle virus is highly diverged from the RdRPs of all known negative-sense RNA viruses and forms a deep branch within the phylum Negarnaviricota, that is not affiliated with any known group of viruses, even at the class level. In contrast, the GPC protein of the turtle virus is confidently affiliated with homologs from a distinct group of fish hantaviruses. Thus, the turtle virus is expected to become the founder of a new taxon of negative-sense RNA viruses, at least with a family rank, but likely, an order or even a class. These viruses probably evolved either by reassortment or by intrasegment recombination between a virus from a distinct branch of negarnaviruses distant from all known groups and a hanta-like aquatic virus. We suggest the provisional name Tosoviridae for the putative new family, with Turtle fraservirus 1 (TFV1) as the type species within the genus Fraservirus. A conventional RT-PCR assay, targeting the TFV1 RdRP, confirmed the presence of viral RNA in multiple tissues and exudates from diseased turtles. The systemic nature of the TFV1 infection was further supported by labeling of cells within lesions using in situ hybridization targeting the RNA of the TFV1 RdRP. Author summary: Freshwater turtles are an important part of aquatic ecosystems, but relatively little is known about diseases that affect them. We discovered a new virus associated with die-offs involving multiple turtle species in Florida. Affected turtles had inflammation involving the nervous system and other organs indicative of viral infection. We isolated a virus from diseased turtles and characterized its morphology using electron microscopy. We also sequenced its entire genome to explore its relatedness to other viruses and developed a PCR-based detection assay. The morphology of the virus particle and genome characteristics were reminiscent of an arenavirus. However, phylogenetic analyses of two viral proteins indicate that the turtle virus most likely evolved through genetic mixing between a distinct branch of RNA viruses distant from all known groups and an aquatic hantavirus. Thus, the turtle virus is expected to become a founding member of a new RNA virus family. We provide evidence linking this novel virus with disease in both wild and captive turtles. [ABSTRACT FROM AUTHOR]

Blood was collected from wild captured green and Kemp's ridley turtles off the west coast of Florida, USA. Blood gases and biochemical values were analyzed using a point of care (POC) device in the field. Analytes include pH, partial pressure of carbon dioxide (pCO2), partial pressure of oxygen (pO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess (BE), oxygen saturation (sO2), lactate, sodium (Na), potassium (K), chloride (Cl), total carbon dioxide (TCO2), anion gap, ionized calcium, glucose, blood urea nitrogen (BUN), creatinine (Crea), hematocrit (Hct), and hemoglobin (Hb). These are novel data for wild healthy Kemp's ridley turtles, and results for green turtles were generally consistent with past studies of green turtles with exceptions primarily in blood gas values. Ninety percent of the green turtles had fibropapillomatosis (FP), but none of the blood analytes were correlated with disease severity. Only BUN was correlated with weight of green turtles, and there was no correlation between blood parameters and weight of Kemp's ridley turtles. This study provides data that are useful in understanding the physiologic status of sea turtles specific to this region, allowing for comparisons to other populations, life stages, and disease states. [ABSTRACT FROM AUTHOR]

Plasma chemistry is widely used in diagnostic and research settings in sea turtles. However, plasma discolorations such as hemolysis are often not considered in data interpretation. The objectives of this study were to (1) evaluate the effects of moderate hemolysis on plasma electrolytes, minerals, and proteins using dry chemistry analysis (DCA) and protein electrophoresis from nesting leatherback sea turtles (Dermochelys coriacea) from Florida and to (2) establish blood analyte reference intervals. Twenty-six plasma samples with absence of hemolysis were selected and sub-divided into one non-hemolytic aliquot and an aliquot that was experimentally manipulated to mimic moderate hemolysis. Plasma samples were analyzed for hemoglobin using a handheld photometer; sodium, potassium, chloride, magnesium, calcium, phosphorus, and total protein using DCA; and protein electrophoresis. Packed cell volume and hemoglobin were measured in corresponding whole blood samples. Reference intervals were established. All analytes except calcium and pre-albumin were significantly higher and the calcium:phosphorus and albumin:globulin ratios were significantly lower in hemolytic plasma compared to non-hemolytic plasma. Alpha2-globulins and potassium were the analytes most impacted by hemolysis, averaging 3.3- and 2.0-fold higher in hemolyzed samples, respectively, indicating that (1) hemoglobin migrates into the alpha2-globulin region in this species and (2) notable intracellular potassium is released into plasma with hemolysis. Attempted conversion factors for compensation of hemolysis were considered inaccurate for 4 of 16 analytes due to non-significant regression lines. We also report that PCV provides an estimate of hemoglobin (g/L) using the formula: (2.59 × PCV) + 24.59. Given the spurious effects of hemolysis, the degree of this artifact should be reported with biochemistry data, and samples with moderate to severe hemolysis should be excluded from datasets when interpreting electrolyte, mineral, and protein results. This will ensure accurate data interpretation for individual turtles in rehabilitation or research settings and population-level data relevant to conservation-focused projects. [ABSTRACT FROM AUTHOR]

The early Pleistocene (ca. 2.588-1.806 Ma) Santa Fe River 1B fossil site (SF1B) of Gilchrist County, Florida has yielded turtle fossils representing nine genera and at least 10 species. Of these, at least six genera are aquatic turtles (Macrochelys and/or Chelydra, Apalone, Trachemys, Pseudemys, Sternotherus, and Kinosternon) and three are terrestrial (Hesperotestudo, Gopherus, and Terrapene). Hesperotestudo and an undescribed cf. Trachemys are the only extinct turtles identified in the paleoherpetofauna. Overall, the generic composition of the turtle fauna is predominantly modern and indicative of the southeastern United States today. [ABSTRACT FROM AUTHOR]

The article discusses a study of B. lineatus or red-shouldered Hawks depredating 8 additional turtle species at a central Florida location and documents chelonophagy by Red-shouldered Hawks and expands the list of known prey species. Topics discussed include the ability of red-shouldered Hawks to adapt to variations in available prey due to geography and seasonal and climatic change and observation that turtles are taken opportunistically as prey and are more prevalent in the Hawk's diet.

The article offers information of TERRAPENE BAURI known as Florida Box Turtle, and the ingestion of plastic by wildlife has received increasing attention due to both the ubiquity of plastic waste in the environment and the mortality and morbidity associated with ingestion.

Under low-resource conditions, the outcome of competition between a generalist omnivore and an herbivore may depend on whether one species can more efficiently use a limiting resource. I evaluated the levels of omnivory and competitive interactions between two abundant sympatric emydid turtles, Trachemys scripta and Pseudemys floridana, that coexist across a productivity gradient in lakes in northern Florida. A foraging experiment indicated that both species were omnivorous in the juvenile stage, but P. floridana was more herbivorous and T. scripta consumed more insects and carrion. This low level of resource overlap was consistent with previous studies of gut contents and stable isotope analyses. In a 13-mo enclosure experiment in a natural pond under low-resource conditions, the generalist T. scripta grew more slowly with conspecifics than with P. floridana, and the more specialized P. floridana grew at the same rate with both T. scripta and conspecifics. Trachemys scripta with P. floridana exhibited the highest growth rate (3.5 mm/yr), slightly faster than P. floridana with conspecifics (2.3 mm/yr). Trachemys scripta was apparently unable to process macroalgae as well as P. floridana and the low abundance of invertebrate prey in the pond may have limited growth rates with conspecifics. Where only low-quality, basal resources are available, gut specializations in P. floridana allow for more efficient digestion and assimilation of plant nutrients and maintenance of equal growth rates with either conspecifics or T. scripta. Where intraspecific competition in one species is stronger than interspecific effects, this may influence the distribution of trophic generalists across a productivity gradient. A possible mechanism for competition among conspecifics may be aggressive interactions in habitats with limited resources. [ABSTRACT FROM AUTHOR]

The high densities of freshwater turtles, along with their Iongevities and tendencies toward omnivory, can make them critical influences on the energy flow in lakes and the resilience of lake food webs. Despite this potential importance, there is little understanding of whether turtle abundances are driven by bottom-up (productivity) or top-down (predation) vectors. In this study I examined the environmental correlates of abundance of three dominant turtle species in 17 northern Florida lakes that span a gradient in primary productivity. I examined the associations between the abundances of the Yellow-Bellied Slider (Trachemys scripta), Florida Cooter (Pseudemys floridana), and Florida Softshell Turtle (Apalone ferox) and 18 environmental factors that varied either discretely or continuously across the lakes. Mantel analyses revealed significant associations between abundance of T. scripto, P. floridana, and A. ferox and periphyton and presence of mud and muck substrates, revealing a significant bottom-up influence. However, abundances were also associated with the presence or absence of alligators, important predators of turtles, indicating a significant top-down influence. The abundances of P. floridana and A. ferox were correlated with additional factors that suggest a role for specific dietary items and trophic position. The results indicate that both bottom-up and top-down controls are important limiting factors to turtle populations and implicate turtles as critical elements in the structure and, perhaps, the stability, of food webs in southeastern lakes. [ABSTRACT FROM AUTHOR]

We analyzed a 15-year (1989 2003) dataset of spatial nesting locations for Loggerhead and Green Turtles along a 40.5-km stretch of beach encompassing the Archie Carr National Wildlife Refuge along the Atlantic coast of Florida. To assess whether there are differences in spatial distribution influenced by temporal site-selection cues, we divided each season into quartiles and analyzed the autocorrelative patterns of the nest distributions within each time frame. Fundamentally, intraspecific differences in nest spatial patterns from the beginning to the end of the nesting season were minor. Though the temporal grain of the analyses may not be able to discern affects of fine-scale fluctuations (e.g., high- and low-tide events), these results suggest that environmental variables that change over the nesting season (e.g., ocean temperatures, daylength, and existing human activities) are not significantly influencing where these sea turtles place their nests. [ABSTRACT FROM AUTHOR]

Examines the diet of immature Kemp's ridley turtles, Lepidochelys Kempi, in Gullivan Bay, Ten Thousand Islands, Florida. Identification of Kemp's ridley turtle as the most endangered sea turtle in the world; Ecology of immature turtles in coastal developmental habitats; Frequencies and quantities of crab species consumed by immature Kemp's ridley turtles.

Presents a study which used radio and sonic telemetry on subadult Kemp's ridley turtles to investigate home-range size and habitat use in the coastal waters of west-central Florida from 1994 to 1996. Regional and stage-specific differences in habitat use; Information on seasonal shifts in habitats; Implications for other life stages of Kemp's ridley turtles.

Presents a study which evaluated the effects of deer feeders, habitat type and visual and olfactory cues on turtle nest predation in northern Florida. Methods; Results and discussion.

Simple Summary: Sea turtles are susceptible to several herpesviruses that are linked to dermatologic diseases, including fibropapillomatosis (FP) and lung-eye-trachea disease. Aside from obvious skin lesions, a number of other sublethal impacts occur in response to these diseases, such as reduced immune function. In this study, we found no relationship between disease presence or severity and T-cell proliferation in green turtles from Florida, USA, at least until the moderate stages of FP; however, natural killer cell activity, a measure of innate immune function, was significantly reduced in turtles with FP compared to tumor-free individuals. This is the first study to examine natural killer cell activity in relation to FP, improving upon our understanding of altered immune system function associated with this disease. Chelonid alphaherpesviruses 5 and 6 (ChHV5 and ChHV6) are viruses that affect wild sea turtle populations. ChHV5 is associated with the neoplastic disease fibropapillomatosis (FP), which affects green turtles (Chelonia mydas) in panzootic proportions. ChHV6 infection is associated with lung-eye-trachea disease (LETD), which has only been observed in maricultured sea turtles, although antibodies to ChHV6 have been detected in free-ranging turtles. To better understand herpesvirus prevalence and host immunity in various green turtle foraging aggregations in Florida, USA, our objectives were to compare measures of innate and adaptive immune function in relation to (1) FP tumor presence and severity, and (2) ChHV5 and ChHV6 infection status. Free-ranging, juvenile green turtles (N = 45) were captured and examined for external FP tumors in Florida's Big Bend, Indian River Lagoon, and Lake Worth Lagoon. Blood samples were collected upon capture and analyzed for ChHV5 and ChHV6 DNA, antibodies to ChHV5 and ChHV6, in vitro lymphocyte proliferation using a T-cell mitogen (concanavalin A), and natural killer cell activity. Despite an overall high FP prevalence (56%), ChHV5 DNA was only observed in one individual, whereas 20% of turtles tested positive for antibodies to ChHV5. ChHV6 DNA was not observed in any animals and only one turtle tested positive for ChHV6 antibodies. T-cell proliferation was not significantly related to FP presence, tumor burden, or ChHV5 seroprevalence; however, lymphocyte proliferation in response to concanavalin A was decreased in turtles with severe FP (N = 3). Lastly, green turtles with FP (N = 9) had significantly lower natural killer cell activity compared to FP-free turtles (N = 5). These results increase our understanding of immune system effects related to FP and provide evidence that immunosuppression occurs after the onset of FP disease. [ABSTRACT FROM AUTHOR]

Presents news briefs related to news in the bioscience field. Concerns from C. Kenneth Dodd, a herpetologist with the U.S. Fish and Wildlife Service in Gainesville, Florida, about the freshwater turtles in Florida; Report that at least one species of Hawaii Drosophila fruitflies produces an unusual sound; Identification by researchers at the University of California, Berkeley, of a gene that ensures the orderly copying of DNA from a common papilloma virus.