Effect of nest temperature on hatchling phenotype of loggerhead turtles (Caretta caretta) from two South Pacific rookeries, Mon Repos and La Roche Percée

2012 ◽  
Vol 60 (6) ◽  
pp. 402 ◽  
Author(s):  
Tyffen Read ◽  
David T. Booth ◽  
Colin J. Limpus
Keyword(s):  
Thermal Tolerance ◽  
Hatching Success ◽  
New Caledonia ◽  
Loggerhead Turtle ◽  
Caretta Caretta ◽  
Nest Temperature ◽  
Genetic Stock ◽  
Upper Limit ◽  
Emergence Success ◽  
The Mean

La Roche Percée, in New Caledonia, is the most important loggerhead turtle rookery outside of Australia for the eastern Pacific genetic stock. The females nesting on this beach are genetically similar to the females found at the Mon Repos rookery in Queensland, Australia. This study shows how nest temperature affects the phenotype of genetically similar populations. During the 2010–11 breeding season, mean nest temperatures were significantly higher at La Roche Percée (31.8°C) than at Mon Repos (29.5°C) and the mean for the three-days-in-a-row maximum nest temperatures was also significantly higher at La Roche Percée (34.6°C), than at Mon Repos (31.7°C). Differences were found in mean hatching success (La Roche Percée 83 ± 3%, Mon Repos 96 ± 2%) and emergence success (La Roche Percée 76 ± 3%, Mon Repos 93 ± 3%). Hatchlings from La Roche Percée also had significantly lower fitness characteristics, having smaller carapace size (La Roche Percée 1565 ± 7 mm2, Mon Repos 1634 ± 5 mm2), slower self-righting times (La Roche Percée 4.7 ± 0.1 s, Mon Repos 2.7 ± 0.1 s) and slower crawling speed in terms of both absolute speed and body lengths per second (La Roche Percée 2.5 ± 0.2 cm s–1 or 0.57 ± 0.05 body lengths s–1, Mon Repos 4.6 ± 0.1 cm s–1 or 1.04 ± 0.02 body lengths s–1). Nest temperatures at La Roche Percée approached the upper limit of embryo thermal tolerance towards the end of incubation (34°C) and this condition may contribute to the lower hatching and emergence success and lower fitness characteristics of hatchlings at the La Roche Percée rookery.

Going back to the roots: finding a strategy for the management of nesting loggerhead sea turtles in New Caledonia

2018 ◽  
Vol 66 (6) ◽  
pp. 394
Author(s):  
Tyffen C. Read ◽  
Marion Petit ◽  
Marion Magnan ◽  
David Booth
Keyword(s):  
Hatching Success ◽  
Incubation Temperature ◽  
New Caledonia ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Vital Role ◽  
Morning Glory ◽  
Root Penetration ◽  
Loggerhead Sea Turtles ◽  
Emergence Success

Incubation temperature plays a vital role in sea turtle life history because it influences embryonic growth, sex determination and hatchling attributes such as body size, residual yolk size, self-righting ability, crawling speed and swimming speed. For these reasons there is concern that predicted increases in air temperature, as a result of global warming, will increase nest temperatures and result in decreased hatching success, decrease or cease male hatchling production, and decreased hatchling quality. In a previous study examining incubation temperature at a loggerhead turtle (Caretta caretta) rookery located at La Roche Percée, New Caledonia, high nest temperatures and root invasion by beach morning glory (Ipomoea pes-caprae) were found to adversely affect hatching success and locomotor performance. In the current study, we relocated loggerhead turtle nests into shaded hatcheries. Shading nests decreased sand and nest temperatures and was predicted to increase male hatchling production slightly, but nest emergence success was decreased due to invasion of cottonwood (Hibiscus tiliaceus) roots into some nests. Using shaded structures is a viable and affordable management option to counteract the high sand temperatures found on some sea turtle nesting beaches, but these shade structures need to be located some distance from trees and other plants to ensure that root penetration into nests does not adversely affect nest emergence success.

Analysis of Elemental Composition of the Eggshell before and after Incubation in the Loggerhead Turtle (Caretta caretta) in Oman

2011 ◽  
Vol 17 (3) ◽  
pp. 452-460 ◽  
Author(s):  
S.N. Al-Bahry ◽  
I.Y. Mahmoud ◽  
K. Melghit ◽  
I. Al-Amri
Keyword(s):  
Elemental Composition ◽  
Amorphous Material ◽  
Loggerhead Turtle ◽  
Middle Layer ◽  
Caretta Caretta ◽  
Exothermic Peak ◽  
Shell Membrane ◽  
Emergence Success ◽  
Significant Difference ◽  
Before And After

AbstractTo date, there are limited studies on loggerhead turtle (Caretta caretta) eggshell ultrastructure and its elemental composition. Eggs were collected from turtle nests immediately after oviposition and post hatching. Three eggshell layers were recognized. The outer calcareous layer consists of loose nodular units of different shapes and sizes with loose attachment between the units, resulting in numerous spaces and openings. Each unit consists of CaCO3crystals in aragonite (99%) and calcite (1%). The middle layer has several strata with numerous openings connecting the calcareous and the inner shell membrane. Crystallites of the middle layer are a mix of amorphous material with aragonite (62%) and calcite (38%). The inner shell membrane has numerous reticular fibers mixed predominantly with halite (NaCl) and small amounts of sylvite. Thermogravimetry analysis of the calcareous showed a low exothermic peak at 425°C, which corresponds to a transitional phase from aragonite to calcite. A high endothermic peak at 814°C corresponds to decomposition of calcite CaCO3to CaO and CO2. Electron diffraction confirmed the presence of NaCl halite crystal. A significant difference was found in the percentage of elements and crystal configurations in the three layers. This study has value in assessing the emergence success in this endangered species.

scholarly journals Impact of the fire ant pesticide AMDRO on loggerhead turtle nest productivity and seafinding orientation

2020 ◽  
Vol 41 ◽  
pp. 339-347
Author(s):  
HE Smith ◽  
SR Hoover ◽  
M Salmon ◽  
H Seaman ◽  
CM Coppenrath ◽  
...  
Keyword(s):  
Nest Site ◽  
Hatching Success ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Fire Ants ◽  
Fire Ant ◽  
Typical Application ◽  
Ghost Crabs ◽  
Emergence Success ◽  
Nesting Beaches

Invasive fire ants prey on a variety of organisms in the southeastern USA, including the pipped eggs and hatchlings within sea turtle nests. The granular fire ant bait AMDRO® (active ingredient hydramethylnon) is currently used at some rookeries to protect nests, but no studies have been conducted to determine if the pesticide negatively impacts the eggs or the hatchlings. We examined the pesticide’s effect on loggerhead (Caretta caretta) nests at Juno Beach, Florida, USA, specifically targeting how exposure affected hatching success, hatchling emergence success, and the ability of the turtles to orient visually from the nest to the sea. Pesticide granules were placed within a 30 cm diameter circle on the sand directly above the nest during the final 5-10 days of incubation, representative of its typical application at nesting beaches. Cornmeal granules in soybean oil and untreated natural nests served as controls. AMDRO had no significant effect on hatching success or emergence success, nor did it result in any deficiencies in hatchling orientation accuracy. However, the pesticide and cornmeal control attracted other predators (Atlantic ghost crabs and avian species), in addition to fire ants, to the nest site, thus revealing the nest’s location and potentially increasing its vulnerability. Consequently, we suggest that its usage may not be beneficial at sites where predators other than ants are especially abundant.

Estimating the sex ratio of loggerhead turtle hatchlings at Mon Repos rookery (Australia) from nest temperatures

2008 ◽  
Vol 56 (1) ◽  
pp. 57 ◽  
Author(s):  
Cuong The Chu ◽  
David T. Booth ◽  
Colin J. Limpus
Keyword(s):  
Sex Ratio ◽  
Constant Temperature ◽  
Loggerhead Turtle ◽  
Temperature Fluctuations ◽  
Daily Temperature ◽  
Nest Temperature ◽  
Emergence Success ◽  
Sand Temperature ◽  
Almost All ◽  
Equivalent Method

Sand temperatures and loggerhead turtle nest temperatures (Caretta caretta) at Mon Repos rookery (Australia) were monitored over the 2005–06 and 2006–07 nesting seasons and hatchling sex ratios of clutches were estimated using the Constant Temperature Equivalent method. Nest temperatures were positively correlated with the sand temperature and air temperature in both seasons. Both seasons produced a female-biased sex ratio, especially the 2005–06 season, when almost all hatchlings were predicted to be female. Hatch success rate was not affected by nest temperature and averaged 85%, but hot nests from 2005–06 had a reduced emergence success compared with other nests. Daily cyclic temperature fluctuations of 0.5–1.5°C were a feature of nests, with a tendency for greater daily amplitude in the 2005–06 season when the average daily temperature was hotter. These daily temperature fluctuations increased the constant temperature equivalent temperature by 0.1–0.5°C above mean nest temperature during the sex-determining period and resulted in an increased female bias in the estimated hatchling sex ratio.

scholarly journals Nesting activity of the Loggerhead sea turtle, Caretta caretta, in Calabria: 2016-2020 reproductive seasons

2021 ◽  
Author(s):  
MARIA DENARO ◽  
TERESA MALITO ◽  
CARMELA MANCUSO ◽  
GIOVANNI PARISE ◽  
SALVATORE URSO
Keyword(s):  
New Technologies ◽  
Survey Methods ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Success Rates ◽  
Monitoring Method ◽  
Loggerhead Sea Turtle ◽  
Emergence Success ◽  
The Mean ◽  
Nesting Activity

The nesting activity of the loggerhead turtle along the coast of Calabria during five reproductive seasons (2016-2020) is presented. From May to August, survey methods were conducted using traditional observations on foot and utilizing additional innovative technologies, including electric fat bikes and drones. Monitoring was intensively focused on a key nesting area of approximately 40 km located on the southernmost Ionian coast of Reggio Calabria, and, for only the 2020 season, the area was extended an additional 40 km northeast. In the five nesting seasons, 419 female emergences were recorded, 192 of which were classified as nests. Overall, 65.1% (n = 125) of nests were found along the area regularly monitored in all nesting seasons. The maximum nesting activity was observed during July, and the mean nesting success was 45.8%. The average number of eggs for all seasons was 92.2 (n = 163; S.D.: ± 21.1; range: 39-160). The mean hatching and emergence success rates were 70.8% and 62.5%, respectively. The mean incubation period was 49 days (n = 122; S.D.: ± 5.4; range: 42-82). Considering previous data from the same area, our study shows an actual increase in nesting activity, probably due to the implementation of an effective monitoring method that includes the use of new technologies, which made it possible to expand the regularly monitored area, and a greater awareness campaign in recent years. Regarding the reproductive parameters, our data is similar to that reported for other Mediterranean nesting grounds.

Population model analysis for the loggerhead sea turtle, Caretta caretta, in Queensland

1996 ◽  
Vol 23 (2) ◽  
pp. 143 ◽  
Author(s):  
SS Heppel ◽  
CJ Limpus ◽  
DT Crouse ◽  
NB Frazer ◽  
LB Crowder
Keyword(s):  
Population Decline ◽  
Survival Rates ◽  
Loggerhead Turtle ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Marine Turtle ◽  
Emergence Success ◽  
Eastern Australia ◽  
Loggerhead Turtles ◽  
The Usa

Worldwide declines of marine turtle populations have forced a need for sound conservation policies to prevent their extinction. Loggerhead turtles, Caretta caretta, are declining rapidly at eastern Australian nesting beaches, which are visited by females from all feeding areas for the stock. In some feeding areas of eastern Australia, loggerheads have been protected from deleterious anthropogenic effects. Using long-term mark-recapture data from one such protected group of turtles feeding on Heron Island Reef, Queensland, we created a matrix model to analyse loggerhead demography. We also produced a model for the females nesting at Mon Repos, Queensland, a major rookery where the annual nesting population has declined at rates approaching 8% per year. As indicated by a similar model for loggerheads in the USA, our models predicted that small declines in annual survival rates of adult and subadult loggerheads can have a profound impact on population dynamics. A loss of only a few hundred subadult and adult females each year could lead to extinction of the eastern Australian loggerheads in less than a century. Survival in the first year of life is relatively less important in these long-lived and slow-maturing animals. At Mon Repos, nesting female survival is apparently so low that even beach protection efforts resulting in 90% hatchling emergence success would not prevent population decline. Our research suggests that continued mortality pressure on subadult and adult turtles in their dispersed feeding areas of eastern and northern Australia is a major threat to the eastern Australian loggerhead turtle population. Measures that protect adult and subadult loggerhead turtles should be supported, including the use of turtle excluder devices (TEDs) on prawn trawls.

Loggerhead turtle(Caretta caretta)by catches on long‐lines: The importance of olfactory stimuli

2004 ◽  
Vol 71 (sup2) ◽  
pp. 213-216 ◽  
Author(s):  
Susanna Piovano ◽  
Emilio Balletto ◽  
Stefano Di Marco ◽  
Alberto Dominici ◽  
Cristina Giacoma ◽  
...  
Keyword(s):  
Loggerhead Turtle ◽  
Caretta Caretta ◽  
Olfactory Stimuli

Prolactin Screening in a Cohort of Schizophrenia Patients in Birmingham

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
I. Waheed ◽  
A. Khan
Keyword(s):  
Health Centre ◽  
Drug Dosage ◽  
Oral Risperidone ◽  
Clinical Symptomatology ◽  
Upper Limit ◽  
Routine Monitoring ◽  
Current Medication ◽  
The Mean ◽  
Unselected Group

Aim:To establish the numerical prevalence and severity of raised prolactin levels in patients apparently asymptomatic.Method:All outpatients with schizophrenia receiving antipsychotics at Small Heath Health Centre had routine annual prolactin measurements. the sampling was done 0900-1300 either in clinic or at patient's homes. the Upper Limit of Normal (ULN) for prolactin was set by the hospital pathology service at 324 mIU/L (males) and 496 mIU/L (females). Sampling was done 0900-1200 either in clinic or at patient's homes. We recorded the patient's name, age, unit number, ethnicity, details of current medication, recent changes to medication and symptoms of hyperprolactinaemia.Results:Prolactin levels were obtained for 43 patients (M: 24 F:19). All of these patients had no clinical symptomatology that had led to prolactin measurements previously. Abnormal values were found in 47 per cent of females and 58 per cent of males, or 56 per cent (n=24) of the whole cohort. the mean prolactin was 789 mIU/L with a mean of 497 mIU/L in males and 1100 mIU/L in females. All patients on oral risperidone had hyperprolactinaemia.Conclusion:Routine prolactin screening showed abnormal values in 56 per cent of patients and significantly abnormal levels (>1000 mIU/L) that should lead to consideration of drug/dosage alterations in 26% of patients. the prevalence of hyperprolactinaemia in an unselected group of outpatients with schizophrenia suggests that consideration may be given to routine monitoring.

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