Author Correction: Sporadic nesting reveals long distance colonisation in the philopatric loggerhead sea turtle (Caretta caretta) (original) (raw)
Related papers
Scientific reports, 2018
The colonisation of new suitable habitats is crucial for species survival at evolutionary scale under changing environmental conditions. However, colonisation potential may be limited by philopatry that facilitates exploiting successful habitats across generations. We examine the mechanisms of long distance dispersal of the philopatric loggerhead sea turtle (Caretta caretta) by analysing 40 sporadic nesting events in the western Mediterranean. The analysis of a fragment of the mitochondrial DNA and 7 microsatellites of 121 samples from 18 of these nesting events revealed that these nests were colonising events associated with juveniles from distant populations feeding in nearby foraging grounds. Considering the temperature-dependent sex determination of the species, we simulated the effect of the incubation temperature and propagule pressure on a potential colonisation scenario. Our results indicated that colonisation will succeed if warm temperature conditions, already existing in ...
Discovery of the northernmost loggerhead sea turtle ( Caretta caretta) nest
Marine Biodiversity Records, 2009
A loggerhead turtle nest was discovered accidentally during the raking of a beach at St Tropez, France, on 18 July 2006. This is so far the northernmost loggerhead nest in the Mediterranean and in the world. The clutch was deposited close to the sea in a sand-soil-pebbles mixture and became partly inundated in September. In total there were 141 eggs, none of which hatched. Only 24% of the eggs contained embryos, while 107 eggs contained yolk but no visible embryo. The failure to hatch was probably the result of the non-suitable nest environment, the low mean incubation temperatures and the inundation. Further observations of beaches are recommended to establish other nesting occurrences of loggerhead turtles in this region. Two species of marine turtles nest in the Mediterranean, the green turtle (Chelonia mydas) and the loggerhead turtle (Caretta caretta) (Margaritoulis et al., 2003), both are classified as endangered on the IUCN Red List of Threatened Species (http://www.iucnredlist.org/). Nesting normally occurs in the eastern basin (Groombridge 1990; Margaritoulis et al., 2003) while only a few occasional nests have been reported for the western Mediterranean (Llorente et al. 1993; Tomás et al., 2002; Delaguerre & Cesarini 2004; Bentivegna et al., 2005; Tomás et al., in press). Here we report on the first loggerhead turtle nest that has ever been recorded in mainland France, and which also presents a new record for nesting activity at latitudes so high to the north. On 18 July 2006 four empty sea turtle egg shells were found on the beach of Saint Elme, St Tropez, France (43°16.05'N 6°39.38'E Figure 1) and reported to the Museum of Monaco, Montecarlo and the Réseau Tortues marines de Mèditerranèe française (French network for marine turtles). One day later intact eggs were discovered by CestMed (Centre d'Etudes et de Sauvegarde des Tortues en Mediterranée) 20 cm beneath the sand where the shells had been found. The nest was close to vegetation and only 8.5 m distant from the water, where the substrate consisted of a mixture of sand, compact and humid soil, dried seagrass and cobblestones. The nest site was protected by a circular fence (height: 1 m, diameter: 1.5 m) and surveyed daily. From 25 July onwards until nest excavation on 14 September sand temperatures were recorded manually each day every six hours with a hand-held digital immersion thermometer (model 30.1021, TFA-Dostmann GmbH, Wertheim-Reicholzheim, Germany, accuracy: ±1°C). Measurements were carried out in proximity of the nest, at 20 cm and at 40 cm depth, to leave the nest itself undisturbed. These temperatures were assumed to resemble most closely those experienced by the eggs at the top and bottom of the egg chamber, respectively (i.e. top eggs were found at 20 cm, the bottom was assumed to be at 40 cm using a mean nest height from bottom to top of egg chamber of 20 cm, cf. Godley et al., 2001) (Figure 1). Sea level rose during a storm on 14 September and the nest was partly inundated. For this reason the egg chamber was excavated on the same day to recover the eggs. The bottom of the egg chamber was 44 cm deep and 8 cm of the chamber were filled with water. A total of 141 eggs was counted, 25 of which showed marked discolouration
Natal homing in juvenile loggerhead turtles (Caretta caretta)
Molecular …, 2004
Juvenile loggerhead turtles ( Caretta caretta ) from West Atlantic nesting beaches occupy oceanic (pelagic) habitats in the eastern Atlantic and Mediterranean, whereas larger juvenile turtles occupy shallow (neritic) habitats along the continental coastline of North America. Hence the switch from oceanic to neritic stage can involve a trans-oceanic migration. Several researchers have suggested that at the end of the oceanic phase, juveniles are homing to feeding habitats in the vicinity of their natal rookery. To test the hypothesis of juvenile homing behaviour, we surveyed 10 juvenile feeding zones across the eastern USA with mitochondrial DNA control region sequences ( N = 1437) and compared these samples to potential source (nesting) populations in the Atlantic Ocean and Mediterranean Sea ( N = 465). The results indicated a shallow, but significant, population structure of neritic juveniles (Φ Φ Φ Φ ST = 0.0088, P = 0.016), and haplotype frequency differences were significantly correlated between coastal feeding populations and adjacent nesting populations (Mantel test R 2 = 0.52, P = 0.001). Mixed stock analyses (using a Bayesian algorithm) indicated that juveniles occurred at elevated frequency in the vicinity of their natal rookery. Hence, all lines of evidence supported the hypothesis of juvenile homing in loggerhead turtles. While not as precise as the homing of breeding adults, this behaviour nonetheless places juvenile turtles in the vicinity of their natal nesting colonies. Some of the coastal hazards that affect declining nesting populations may also affect the next generation of turtles feeding in nearby habitats.
Natal homing in juvenile loggerhead turtles (Caretta caretta): JUVENILE LOGGERHEAD HOMING
Molecular Ecology, 2004
Juvenile loggerhead turtles (Caretta caretta) from West Atlantic nesting beaches occupy oceanic (pelagic) habitats in the eastern Atlantic and Mediterranean, whereas larger juvenile turtles occupy shallow (neritic) habitats along the continental coastline of North America. Hence the switch from oceanic to neritic stage can involve a trans-oceanic migration. Several researchers have suggested that at the end of the oceanic phase, juveniles are homing to feeding habitats in the vicinity of their natal rookery. To test the hypothesis of juvenile homing behaviour, we surveyed 10 juvenile feeding zones across the eastern USA with mitochondrial DNA control region sequences (N = 1437) and compared these samples to potential source (nesting) populations in the Atlantic Ocean and Mediterranean Sea (N = 465). The results indicated a shallow, but significant, population structure of neritic juveniles (ΦST = 0.0088, P = 0.016), and haplotype frequency differences were significantly correlated between coastal feeding populations and adjacent nesting populations (Mantel test R2 = 0.52, P = 0.001). Mixed stock analyses (using a Bayesian algorithm) indicated that juveniles occurred at elevated frequency in the vicinity of their natal rookery. Hence, all lines of evidence supported the hypothesis of juvenile homing in loggerhead turtles. While not as precise as the homing of breeding adults, this behaviour nonetheless places juvenile turtles in the vicinity of their natal nesting colonies. Some of the coastal hazards that affect declining nesting populations may also affect the next generation of turtles feeding in nearby habitats.
Nest placement by loggerhead turtles, Caretta caretta
Animal Behaviour, 1993
Nest placement by loggerhead turtles nesting on the island of Cephalonia, Greece, was examined. The spatial distribution of nests was not uniform (N = 27 nests): they tended to be laid away from the sea, but not in vegetation that backed the beach. Hatchling success (recorded for eight nests) increased significantly for nests laid further from the sea. Hence most nests were laid in positions where hatchling success was high. Six individuals were observed to nest more than once. Each of these multiple nesters showed little consistency in the distance that they nested from the sea (i.e. within-individual variation was high), and hence no significant differences in nest positioning between individuals were detected ..Digging attempts in the vegetation behind the beach were frequently aborted (71 % of attempts), but attempts in the open sand between the vegetation and the sea were aborted less often (11 % of attempts). Sand temperatures at the depths where eggs incubated were higher further from the sea. The implications of nest placement for hatchling sex ratio are discussed.
PROCEEDINGS OF THE NINETEENTH ANNUAL SYMPOSIUM ON SEA TURTLE CONSERVATION AND BIOLOGY
TM 443:101-103, 1999
NOAA NMFS - 443 PP. 101-103 "The first described fossilized sea turtle nests occur as sedimentary structures preserved in the Fox Hills Sandstone, Elbert County, Colorado. They are Cretaceous analogs to Recent loggerhead sea turtle nests studied on St. Catherines Island, GA (Marsh and Bishop, 1993). Although sea turtles have an extensive geological record extending at least into the Jurassic and Early Cretaceous (Nicholls, 1997; Hirayama, 1997), traces of their terrestrial nesting activities (Caldwell, Carr, and Ogren, 1959; Witherington [and Witherington, 2016]; Hailman and Elowson, 1992) have not been well documented in the literature and fossil traces have only recently been described (Bishop et al., 1997, [ 2011])." N.B. Abstract slightly modified to new literature.
Egg Failure in Natural and Relocated Sea Turtle Nests
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.
Nest-Site Selection in Individual Loggerhead Turtles and Consequences for Doomed-Egg Relocation
Conservation Biology, 2009
trait, relocating eggs deposited in vulnerable locations may impose artificial selection that would maintain traits favoring unsuccessful nest-site selection. Conversely, if most individuals scatter their nesting effort and individuals that consistently select unsuccessful nest sites are uncommon, then artificial selection would be less of a concern. During the 2005 nesting season of loggerhead turtles (Caretta caretta) at Mon Repos beach, Queensland, Australia, we measured the perpendicular distance from the original nest site to a stationary dune baseline for in situ (unrelocated) and relocated clutches of eggs. We observed the fate of in situ clutches and predicted what would have been the fate of relocated clutches if they had not been moved by mapping tidal inundation and storm erosion lines. In 2005 turtles deposited an average of 3.84 nests and did not consistently select nest sites at particular distances from the stationary dune baseline. Selection of unsuccessful nest sites was distributed across the nesting population; 80.3% of the turtles selected at least one unsuccessful nest site and when previous breeding seasons were included, 97% selected at least one unsuccessful nest site. Females with nesting experience selected more successful nest sites than females with little or no experience. Relocating eggs vulnerable to tidal inundation and erosion saves the progeny from a large percentage of the population and the progeny from individuals who may in subsequent years nest successfully. Our results suggest that doomed-egg relocation does not substantially distort the gene pool in the eastern Australian loggerhead stock and should not be abandoned as a strategy for the conservation of marine turtle populations.