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.

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.

scholarly journals Effects of Fire Ants (Hymenoptera: Formicidae) on Hatching Turtles and Prevalence of Fire Ants on Sea Turtle Nesting Beaches in Florida

2001 ◽  
Vol 84 (2) ◽  
pp. 250 ◽  
Author(s):  
Craig R. Allen ◽  
Elizabeth A. Forys ◽  
Kenneth G. Rice ◽  
Daniel P. Wojcik
Keyword(s):  
Sea Turtle ◽  
Fire Ants ◽  
Nesting Beaches

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.

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.

scholarly journals Olive Ridley Sea Turtle Hatching Success as a Function of Microbial Abundance and the Microenvironment ofIn SituNest Sand at Ostional, Costa Rica

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Vanessa S. Bézy ◽  
Roldán A. Valverde ◽  
Craig J. Plante
Keyword(s):  
Organic Matter ◽  
Costa Rica ◽  
Hatching Success ◽  
Quantitative Polymerase Chain Reaction ◽  
Organic Matter Content ◽  
Sea Turtle ◽  
High Density ◽  
Microbial Abundance ◽  
Olive Ridley ◽  
Nesting Beaches

Sea turtle hatching success at mass nesting beaches is typically lower than at solitary nesting beaches, presumably due in part to high rates of microbial metabolism resulting from the large input of organic matter from turtle eggs. Therefore, we tested the hypothesis that hatching success varies across areas of the beach in conjunction with differences in the physical nest environment and microbial abundance of in situ olive ridley sea turtle nests at Ostional, Costa Rica. We marked natural nests in high-density, low-density, and tidal-wash nesting areas of the beach and monitored clutch pO2and temperature throughout the incubation period. We quantified hatching success and collected samples of nest sand during nest excavations. We quantified microbial abundance (bacteria and fungi) with a quantitative polymerase chain reaction (qPCR) analysis. Hatching success was lower in nests with lower pO2, higher temperatures, higher organic matter content, and higher microbial abundance. Our results suggest that the lower oxygen within the nest environment is likely a result of the high microbial abundance and rates of decomposition in the nest sand and that these factors, along with increased temperature of clutches in the high-density nesting area, are collectively responsible for the low hatching success at Ostional.

scholarly journals Globally important refuge for the loggerhead sea turtle: Maio Island, Cabo Verde

Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Juan Patino-Martinez ◽  
Leno Dos Passos ◽  
Inês O. Afonso ◽  
Arnau Teixidor ◽  
Manjula Tiwari ◽  
...  
Keyword(s):  
Management Strategy ◽  
Hatching Success ◽  
Management Strategies ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Sandy Beaches ◽  
Loggerhead Sea Turtle ◽  
Artificial Lighting ◽  
Cabo Verde ◽  
Comprehensive Study

Abstract One of the largest nesting colonies of the Vulnerable loggerhead sea turtle Caretta caretta is in Cabo Verde. Here we present the first comprehensive study of loggerhead turtle nesting on the island of Maio in Cabo Verde. During 2016–2019 we monitored 38 km of undeveloped sandy beaches that have minimal artificial lighting and where all nesting on Maio takes place. We counted 4,063 nests in 2016, 5,429 in 2017, 14,364 in 2018 and 7,937 in 2019. The estimated total number of females was 1,016, 1,357, 3,591 and 1,984 in each of these years, respectively. Our findings suggest there are more loggerhead turtles nesting in Cabo Verde than previously estimated, and that this could be the species’ largest nesting subpopulation (followed by Florida, USA and Oman). The inter-annual hatching success (the proportion of eggs producing hatchlings) was 29–38% for the whole island but varied between sites. Our study of 250 clutches showed that flooding affected 38–61% and predation by crabs 40–42%, with hatching success on different beaches in the range of 1–59%. Poaching of eggs was rare (< 2% of clutches), but dogs predated 68.4% of all clutches on the beach nearest the largest human settlement. We evaluated different nest management strategies at multiple sites and estimated productivity of hatchlings (the number of hatchlings that would reach the sea for each management strategy), finding that hatcheries are not always the best option for nest management. As the beaches on Maio are relatively undisturbed, and there is a high abundance and density of turtle nests, the island should be protected as a globally important site for the conservation of the loggerhead turtle, and of coastal biodiversity more broadly.

scholarly journals Predaceous Fire Ants (Hymenoptera: Formicidae) at Sea Turtle (Testudines: Cheloniidae) Nesting Beaches and Hatcheries in El Salvador

2016 ◽  
Vol 99 (1) ◽  
pp. 106-109 ◽  
Author(s):  
James K. Wetterer ◽  
Michael J. Liles ◽  
José M. Sermeño ◽  
Leopoldo Serrano Cervantes ◽  
Eunice E. Echeverria ◽  
...  
Keyword(s):  
El Salvador ◽  
Sea Turtle ◽  
Fire Ants ◽  
Nesting Beaches

scholarly journals How will changes in local climate affect hawksbill hatchling production in Brazil?

2018 ◽  
Author(s):  
Natalie Montero ◽  
Maria A.G. dei Marcovaldi ◽  
Milagros Lopez–Mendilaharsu ◽  
Alexsandro S. Santos ◽  
Armando J. B. Santos ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Hatching Success ◽  
Rio Grande ◽  
Sea Turtle ◽  
Climatic Conditions ◽  
Future Climate Change ◽  
Average Precipitation ◽  
Climatic Drivers ◽  
Nesting Beaches

AbstractLocal climatic conditions can influence sea turtle embryonic development and hatchling viability. Therefore, it is crucial to understand these influences as well as potential ramifications to population stability under future climate change. Here, we examined the influences of five climatic variables (air temperature, accumulated and average precipitation, humidity, solar radiation, and wind speed) at different temporal scales on hawksbill sea turtle (Eretmochelys imbricata) hatchling production at ten nesting beaches within two regions of Brazil (five nesting beaches in Rio Grande do Norte and five in Bahia). Air temperature and accumulated precipitation were the main climatic drivers of hawksbill hatching success across Brazil and in Rio Grande do Norte, while air temperature and average precipitation were the main climatic drivers of hatching success at Bahia. Solar radiation was the main climatic driver of emergence rate at both regions. Conservative and extreme climate scenarios show air temperatures are projected to increase, while precipitation projections vary between scenarios and regions throughout the 21st century. We predicted hatching success of undisturbed nests (no recorded depredation or storm-related impacts) will decrease in Brazil by 2100. This study shows the determining effects of different climate variables and their combinations on an important and critically endangered marine species.

scholarly journals Nest microbiota and pathogen abundance impact hatching success in sea turtle conservation

2019 ◽  
Author(s):  
Daphne Z Hoh ◽  
Yu-Fei Lin ◽  
Wei-An Liu ◽  
Siti Nordahliawate Mohamed Sidique ◽  
Isheng Jason Tsai
Keyword(s):  
Hatching Success ◽  
Amplicon Sequencing ◽  
Sea Turtle ◽  
Microbial Composition ◽  
Pseudallescheria Boydii ◽  
Predominant Species ◽  
Turtle Conservation ◽  
Sea Turtle Conservation ◽  
Nesting Beaches ◽  
Nesting Season

AbstractHatchery practices are pivotal to conservation success. In sea turtle hatchery, reusing the same sand has been a norm but remains unclear whether such approach increases the risk of Fusarium solani species complex (FSSC) infection causing huge mortality in sea turtle eggs worldwide. We employed 16S and ITS amplicon sequencing in 123 sand samples and isolated fungal strains from diseased eggs across seven hatcheries and neighboring beaches in Malaysia. FSSC was isolated from all sampled hatcheries where F. solani/falciforme was the predominant species. A distinct microbial composition and higher abundance of FSSC (mean = 5.2 %) was found in all but one hatchery when compared to nesting beaches (mean = 1.3 %). Specifically, an ascomycetous fungus Pseudallescheria boydii consistently appeared in higher abundance (mean = 11.4 %) in FSSC-infected nests and was significantly associated with lower hatching success. The hatchery that maintained the most stringent practice by changing sand every nesting season had a microbiota resembling nesting beaches as well as lowest FSSC and P. boydii abundance. The results of current study imply the need to avoid reusing sand in sea turtle hatchery.

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.

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