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1.
M. Revelles C. Carreras L. Cardona F. Bentivegna G. de Martino M.B. Smith M. Pascual 《Journal of experimental marine biology and ecology》2007,349(2):261-271
The permanent eastward current at the Straits of Gibraltar may trap small Atlantic loggerhead sea turtles (Caretta caretta) inside the western Mediterranean until their swimming and diving skills improve enough to allow them counter-current swimming abilities through the current. A captivity experiment with twelve loggerhead sea turtles (straight carapace length or SCL range: 25.3-48.0 cm) revealed that the average critical velocity of this species within the considered length range was 0.38 ± 0.16 m s− 1 or 1.01 ± 0.24 bl s− 1. As a consequence, loggerhead sea turtles are predicted to require a minimum SCL of 36.0 cm to swim counter-current through the Straits of Gibraltar, where the water velocity ranges 0.31-0.37 m s− 1. Genetic analysis of 105 specimens using one mitochondrial marker and seven microsatellites, as well as the recapture of three tagged individuals, support this conclusion; all Mediterranean individuals found in the Atlantic side of the Straits were not smaller than 36.0 cm SCL and the average length (47.3 cm SCL) was significantly higher than that of the Mediterranean turtles in the Mediterranean side of the Straits (31.6 cm SCL). Furthermore, the average length of the turtles of any origin moving from the Mediterranean to the Atlantic was much larger than 36.0 cm (SCL: 54.5 cm SCL), which may indicate the intervention of a different, yet unidentified mechanism restricting east-westward movement. The Algerian current, running along northern Africa, may at least partially explain the delayed departure of loggerhead sea turtles from the Mediterranean Sea to the Atlantic Ocean, as it would force the eastward drift of loggerheads occupying the southwestern Mediterranean. Exchange through the Straits is asymmetrical, and Atlantic turtles are found to enter the Mediterranean at a length of about 20.5 cm. However, once in the Mediterranean they would be retained there for up to 7.9 years, due to the surface circulation pattern. This increases the time span at which turtles are exposed to a high mortality rate, caused by fishing. 相似文献
2.
Michael S. Painter;Václav Silovský;Justin Blanco;Mark Holton;Monika Faltusová;Rory Wilson;Luca Börger;Liza Psotta;Fabian Ramos-Almodovar;Luis Estrada;Lukas Landler;Pascal Malkemper;Vlastimil Hart;Miloš Ježek; 《Ecology and evolution》2024,14(9):e70264
Biologging has proven to be a powerful approach to investigate diverse questions related to movement ecology across a range of spatiotemporal scales and increasingly relies on multidisciplinary expertise. However, the variety of animal-borne equipment, coupled with little consensus regarding analytical approaches to interpret large, complex data sets presents challenges and makes comparison between studies and study species difficult. Here, we present a combined hardware and analytical approach for standardizing the collection, analysis, and interpretation of multisensor biologging data. Here, we present (i) a custom-designed integrated multisensor collar (IMSC), which was field tested on 71 free-ranging wild boar (Sus scrofa) over 2 years; (ii) a machine learning behavioral classifier capable of identifying six behaviors in free-roaming boar, validated across individuals equipped with differing collar designs; and (iii) laboratory and field-based calibration and accuracy assessments of animal magnetic heading measurements derived from raw magnetometer data. The IMSC capacity and durability exceeded expectations, with a 94% collar recovery rate and a 75% cumulative data recording success rate, with a maximum logging duration of 421 days. The behavioral classifier had an overall accuracy of 85% in identifying the six behavioral classes when tested on multiple collar designs and improved to 90% when tested on data exclusively from the IMSC. Both laboratory and field tests of magnetic compass headings were in precise agreement with expectations, with overall median magnetic headings deviating from ground truth observations by 1.7° and 0°, respectively. Although multisensor equipment and sophisticated analyses are now commonplace in biologging studies, the IMSC hardware and analytical framework presented here provide a valuable tool for biologging researchers and will facilitate standardization of biologging data across studies. In addition, we highlight the potential of additional analyses available using this framework that can be adapted for use in future studies on terrestrial mammals. 相似文献
3.
《Animal cells and systems.》2012,16(2):177-181
Blood samples collected from green (Chelonia mydas), loggerhead (Caretta caretta), and Kemp's ridley (Lepidochelys kempii) sea turtles were analyzed by radioimmunoassay to detect seasonal variations in thyroid hormones and compare levels in wild and captive individuals. Sexual dimorphism in the annual cycle of thyroxine was observed in adult Kemp's ridley. No differences were observed between immature male and female green and loggerhead sea turtles. The level of triiodothyronine was consistently low relative to thyroxine in all species investigated, and captive sea turtles exhibit higher plasma thyroid levels than do wild ones 相似文献
4.
Hard armoring technologies (e.g. rock revetments and seawalls), which are installed to protect homes from beach erosion, can diminish the aesthetics and amenity of the beach. Over time, these structures cause beach narrowing and often prevent marine turtle access to nesting habitat altogether. An alternative armoring technology, known as geotextile dune core systems (or geocores), has been developed and implemented to protect inland infrastructure from beach erosion, yet there remains an absence of research on possible effects on marine turtles. In this study, we examined the impacts of a geocore installed on Juno Beach, Florida, United States in February 2014 on loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting success, hatching success, and emergence success. A before‐after‐control‐impact paired series design evaluated the difference in nesting success per week for the impact and control sites 4 years before (2010–2013) and 4 years after (2014–2017) the installation of the geocore. Neither loggerhead nor green turtle nesting success was significantly different after the installation of the geocore; however, when analyzing loggerhead crawls that came to within 5 m of the geotextile bags, nesting success decreased. Neither hatching nor emergence success was significantly different after the installation of the geocore for either species. Our results suggest that geocores may minimally affect loggerhead and green turtles and provide a suitable restoration technique for homeowners facing beach erosion. 相似文献
5.
The goal of this study was to assess the consequences of single versus multiple paternity by identifying paternity of clutches per female to identify whether there were detectable costs or benefits. Multiple mating can occur when the benefits of mating outweigh the costs, but if costs and benefits are equal, no pattern is expected. Previous research on loggerhead sea turtle (Caretta caretta) populations found male‐biased breeding sex ratios and multiple mating by many females nesting in southwestern Florida. A sample of nesting loggerhead females who laid more than one nest over the course of the season and a subset of their hatchlings were examined from 36 clutches in 2016 on Sanibel Island, Florida. Males that fathered hatchlings in the first clutch sampled were identified in subsequent clutches. Interestingly, 75% of the females analyzed had mated singly. No male was represented in more than one female's clutches. The results suggest that females likely mate at the beginning of the season and use stored sperm for multiple clutches. Evidence for mating between laying events was limited. There was no consistent pattern across the subsequent multiple paternity clutches, suggesting benefits to loggerhead females likely equal their costs and subsequent mating is likely determined by female preference. 相似文献
6.
Increasingly, animal behavior studies are enhanced through the use of accelerometry. To allow translation of raw accelerometer data to animal behaviors requires the development of classifiers. Here, we present the “rabc” (r for animal behavior classification) package to assist researchers with the interactive development of such animal behavior classifiers in a supervised classification approach. The package uses datasets consisting of accelerometer data with their corresponding animal behaviors (e.g., for triaxial accelerometer data along the x, y and z axes arranged as “x, y, z, x, y, z,…, behavior”). Using an example dataset collected on white stork (Ciconia ciconia), we illustrate the workflow of this package, including accelerometer data visualization, feature calculation, feature selection, feature visualization, extreme gradient boost model training, validation, and, finally, a demonstration of the behavior classification results. 相似文献
7.
The onset of spring, noted by the timing of wildlife migratory and breeding behaviors, has been occurring earlier over the past few decades. Here, we examine 15 years of loggerhead sea turtle, Caretta caretta, nesting patterns along a 40.5 km beach on Florida's Atlantic coast. This small section of beach is considered to be the most important nesting area for this threatened species in the western hemisphere. From 1989 to 2003, the annual number of nests fluctuated between 13 000 and 25 000 without a conspicuous trend; however, based on a regression analysis, the median nesting date became earlier by roughly 10 days. The Julian day of median nesting was significantly correlated with near‐shore, May sea surface temperatures that warmed an average of 0.8°C over this period. This marine example from warm temperate/subtropical waters represents another response of nature to recent climate trends. 相似文献
8.
Mariana M. P. B. Fuentes David A. Pike Andrew Dimatteo Bryan P. Wallace 《Global Change Biology》2013,19(5):1399-1406
Enhancing species resilience to changing environmental conditions is often suggested as a climate change adaptation strategy. To effectively achieve this, it is necessary first to understand the factors that determine species resilience, and their relative importance in shaping the ability of species to adjust to the complexities of environmental change. This is an extremely challenging task because it requires comprehensive information on species traits. We explored the resilience of 58 marine turtle regional management units (RMUs) to climate change, encompassing all seven species of marine turtles worldwide. We used expert opinion from the IUCN‐SSC Marine Turtle Specialist Group (n = 33 respondents) to develop a Resilience Index, which considered qualitative characteristics of each RMU (relative population size, rookery vulnerability, and genetic diversity) and non climate‐related threats (fisheries, take, coastal development, and pollution/pathogens). Our expert panel perceived rookery vulnerability (the likelihood of functional rookeries becoming extirpated) and non climate‐related threats as having the greatest influence on resilience of RMUs to climate change. We identified the world's 13 least resilient marine turtle RMUs to climate change, which are distributed within all three major ocean basins and include six of the world's seven species of marine turtle. Our study provides the first look at inter‐ and intra‐species variation in resilience to climate change and highlights the need to devise metrics that measure resilience directly. We suggest that this approach can be widely used to help prioritize future actions that increase species resilience to climate change. 相似文献
9.
M.A. Brodie A. Walmsley W. Page 《Computer methods in biomechanics and biomedical engineering》2013,16(6):641-648
Inertial measurement units (IMUs) are integrated electronic devices that contain accelerometers, magnetometers and gyroscopes. Wearable motion capture systems based on IMUs have been advertised as alternatives to optical motion capture. In this paper, the accuracy of five different IMUs of the same type in measuring 3D orientation in static situations, as well as the calibration of the accelerometers and magnetometers within the IMUs, has been investigated. The maximum absolute static orientation error was 5.2°, higher than the 1° claimed by the vendor. If the IMUs are re-calibrated at the time of measurement with the re-calibration procedure described in this paper, it is possible to obtain an error of less than 1°, in agreement with the vendor's specifications (XSens Technologies B.V. 2005. Motion tracker technical documentation Mtx-B. Version 1.03. Available from: www.xsens.com). The new calibration appears to be valid for at least 22 days providing the sensor is not exposed to high impacts. However, if several sensors are ‘daisy chained’ together changes to the magnetometer bias can cause heading errors of up to 15°. The results demonstrate the non-linear relationship between the vendor's orthogonality claim of < 0.1° and the accuracy of 3D orientation obtained from factory calibrated IMUs in static situations. The authors hypothesise that the high magnetic dip (64°) in our laboratory may have exacerbated the errors reported. For biomechanical research, small relative movements of a body segment from a calibrated position are likely to be more accurate than large scale global motion that may have an error of up to 9.8°. 相似文献
10.
目的研究太平洋丽龟的生理结构及特点,为我国开展海龟保育和科学研究提供参考。方法对1只误捕致死的太平洋丽龟进行解剖,观察其循环系统、消化系统、呼吸系统和泄殖系统并测量记录。结果太平洋丽龟心脏位于胸部正中、稍偏右;食管内壁分布许多锥状突起;小肠长240cm,占整个消化系统管道总长的53.1%,消化道总长与体长的比值(简称肠长比)为5.35;精巢1对,阴茎长30cm,可推断为成年的雄龟。结论太平洋丽龟的生理结构估计与其肉食性有关,这对开展人工驯养繁育和物种保护具有重要意义。 相似文献
11.
Ian Silver-Gorges;Brian M. Shamblin;Mason Ashford;Paityn Bower;Mariana M. P. B. Fuentes; 《Ecology and evolution》2024,14(9):e70166
Small populations of imperiled species are susceptible to the negative consequences of skewed sex-ratios. In imperiled species with environmental sex determination such as sea turtles, examining sex ratios across a range of environments and population abundance levels can provide insight into factors that influence population resilience, which can then be the foci of management plans for these species. Breeding sex ratios (the ratio of actively breeding males to females during a reproductive season; BSRs) extrapolated from genetic parentage analyses are a common approach for enumerating sex ratios in sea turtles. Such analyses also allow for the characterization of multiple paternity within sea turtle clutches, which should reflect BSRs and breeding behaviors. We characterized the first BSR for a breeding assemblage of loggerhead sea turtles (Caretta caretta) belonging to the temperate, low-abundance Northern Gulf of Mexico Recovery Unit using genotypes of 16 microsatellite loci from nesting females and hatchlings. Unlike prior studies at both more-tropical and more-temperate, and higher-abundance, Recovery Units in this region, we found a balanced BSR of 1.3:1 males:female and a low incidence (~17%) of multiple paternity. This suggests that there are relatively few males breeding at this assemblage and within this Recovery Unit. Beaches in this region are expected to produce substantial numbers of male hatchlings based on sand temperature data. The relative dearth of mature males may then be due to hydrologic disturbances that disproportionately affect the fitness and survival of male hatchlings, or due to demographic stochasticity. More work is needed to study the factors that might influence male hatchling production and fitness in this region, particularly as climate change is predicted to lead to feminization in global sea turtle populations. Our work demonstrates the broad utility of characterizing BSRs and other sex ratios across a range of populations in imperiled, environmentally sensitive species. 相似文献
12.
P. Luschi F. Papi H. C. Liew E. H. Chan F. Bonadonna 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1996,178(4):447-452
Four green turtle females were tracked by satellite during their post-reproductive migration in the South China Sea. Three of them reached their feeding grounds 923–1551 km distant. During nesting activity, a female was displaced twice, and her return trips to the nesting beach from 11 and 284 km were tracked by a direction-recording data-logger and by satellite, respectively. Part of the journeys occurred coastwise, indicating that leading geographical features had been utilised. The straightness of the turtles' tracks in open seas, both over shallow and deep waters, and their ability to pinpoint distant targets and home after displacement off their usual routes, provides circumstantial evidence for a true navigation mechanism.Abbreviation PTT platform transmitter terminal 相似文献
13.
自2001年来,惠东港口海龟国家级自然保护区已成功地利用卫星追踪了21只海龟的洄游路线。本文利用美国卫星信号发射器(Tag)和法国Argos系统追踪3只成年雌性绿海龟。跟踪海龟"西沙"和"南沙"26d,二者均在海口市附近海域消失;"东沙"从阳江市海陵岛出发,取东南向至菲律宾,然后沿菲律宾西海岸向南,最后在巴拉望岛西侧海域逗留,共追踪111d。该试验说明港口海龟具有不同的洄游线路,偏爱沿岸的浅海洄游;洄游路线与等温线之间无显著关系;海龟洄游具有明确的目的地。建议政府相关部门采取科学策略来保护海龟。 相似文献
14.
BRIAN M. SHAMBLIN BRANT C. FAIRCLOTH MARK DODD ALICIA WOOD‐JONES STEVEN B. CASTLEBERRY JOHN P. CARROLL C. JOSEPH NAIRN 《Molecular ecology resources》2007,7(5):784-787
We describe primers and polymerase chain reaction conditions to amplify 15 tetranucleotide microsatellite loci from the loggerhead sea turtle (Caretta caretta). The primers were tested on 30 individuals that nested along the Georgia, USA coast. The primer pairs developed in this study yielded an average of 13.9 alleles per locus (range of 10–21), an average observed heterozygosity of 0.91 (range 0.79–1.00), and an average polymorphic information content of 0.88 (range 0.84–0.92). 相似文献
15.
Abstract We review some key resources freely or cheaply available to those involved with marine turtle research and conservation in the Mediterranean. These include: Marine Turtle Newsletter, Listservs, bibliographic databases, Mediterranean specific technical manuals, IUCN Marine Turtle Specialist Group publications, internet sources and books. 相似文献
16.
Mating‐induced ovulation is common in mammals, but has been rarely described in other taxa. Observations of several mature female loggerhead sea turtles, Caretta caretta, held in captivity seemed to indicate that ovulation did not occur in the absence of a male. This study was designed to determine whether this was an effect of captivity or an effect of the absence of a male. Two mature female loggerheads were followed over six annual reproductive cycles. Ultrasound exams were performed approximately every 2 weeks to follow the development of follicles in the ovaries. During the first two seasons, no male was present, in the next two seasons, a mature male was present without mating, and in the final two seasons a mature male was present, mating with one or both females. When no male was present or when present without mating, ovarian follicles developed to full size, but ovulation did not occur and the follicles gradually began to decrease in diameter and undergo changes evident on ultrasound. In the fifth season, only one of the females mated, dropping two eggs after 7 days, and continued to oviposit throughout the following months (total 275 eggs). The unmated female did not ovulate, showing the same pattern as earlier seasons. In the final season, both females mated and ovulated, dropping eggs for the next four months (total 539 eggs). The following year, no males were present and neither female ovulated. This study provides clear evidence that ovulation in loggerhead sea turtles is induced by mating. Zoo Biol 27:213–225, 2008. © 2008 Wiley‐Liss, Inc. 相似文献
17.
Caretta caretta (loggerhead sea turtle) nesting activity was recorded daily during three seasons prior to and two seasons immediately following a beach nourishment (replenishment) project in Palm Beach County, Florida. Surveys were done at the nourished beach (Jupiter/Carlin) and at two natural beaches (Juno and Tequesta). The size of the nourishment effect on nesting activity was estimated using Before‐After‐Control‐Impact Paired Series (BACIPS) models. Nesting declined by 4.4 to 5.4 nests km ? 1 day ? 1 on the nourished beach compared to the two natural beaches in the first season after nourishment. At the same time, false crawls (FC, non‐nesting crawls) increased by 5.0 to 5.6 FC km ? 1 day ? 1 on the nourished beach. In the second season following nourishment, nesting was reduced by 0.5 to 1.6 nests km ? 1 day ? 1 on the nourished beach compared to the two natural beaches. The increase in false crawl frequency in the second season following nourishment was 0.7 to 0.9 FC km ? 1 day ? 1.These results suggest that beach nourishment significantly decreased loggerhead sea turtle nesting during the first season following the project. However, the size of the effect, in terms of nesting frequency and false crawl frequency, was much reduced by the second season following nourishment. 相似文献
18.
A. Alonso Aguirre Susan C. Gardner Jesse C. Marsh Stephen G. Delgado Colin J. Limpus Wallace J. Nichols 《EcoHealth》2006,3(3):141-153
Sea turtle products (e.g., meat, adipose tissue, organs, blood, eggs) are common food items for many communities worldwide,
despite national regulations in some countries prohibiting such consumption. However, there may be hazards associated with
this consumption due to the presence of bacteria, parasites, biotoxins, and environmental contaminants. Reported health effects
of consuming sea turtles infected with zoonotic pathogens include diarrhea, vomiting, and extreme dehydration, which occasionally
have resulted in hospitalization and death. Levels of heavy metals and organochlorine compounds measured in sea turtle edible
tissues exceed international food safety standards and could result in toxic effects including neurotoxicity, kidney disease,
liver cancer, and developmental effects in fetuses and children. The health data presented in this review provide information
to health care providers and the public concerning the potential hazards associated with sea turtle consumption. Based on
past mortality statistics from turtle poisonings, nursing mothers and children should be particularly discouraged from consuming
all sea turtle products. We recommend that individuals choose seafood items lower in the food chain that may have a lower
contaminant load. Dissemination of this information via a public health campaign may simultaneously improve public health
and enhance sea turtle conservation by reducing human consumption of these threatened and endangered species. 相似文献
19.
20.
Craven KS Parsons J Taylor SA Belcher CN Owens DW 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2008,178(4):495-500
Fatty acid concentrations found in the yolk of green sea turtles reflect differences in the diet of the mothers. All of the
12 fatty acids measured in yolk samples were significantly different between eggs produced from the pellet and wild-type diets.
However, the relative pattern of yolk fatty acids in the green turtle mirrored those of other reptiles. Yolk samples contained
mostly (63–67%) 14:0. 16:0, 16:1n-7 and 18:1n-9. Yolks from captive animals on pellet diet contained an additional 17.64%
of the total yolk lipid as 12:0 and 18:2n-6. Wild yolks contained an extra 11.41% of lipid as 18:0 and 18:1n-7. Selection
of fatty acids for the yolk should balance the energetic and anabolic needs of the embryo. Eggs are provisioned based on maternal
metabolism of available nutrients and subtle differences between natural foods and those available in captivity could affect
the viability of future eggs. 相似文献