In a pioneering study by Florida Atlantic University, the unique leatherback sea turtle (Dermochelys coriacea), known for its smooth, leathery carapace, took center stage. This species, classified as vulnerable, faces population declines from a gamut of natural and human-induced threats, most notably climate change—a critical aspect of their survival hinges on the environmental conditions within their nesting sites. Elevated sand temperatures during incubation can hinder embryonic development, causing reduced hatching success and compromising hatchling performance. Ensuring the physical fitness of hatchlings is paramount for their safe journey from the nest to the ocean, where they evade potential threats like seabirds and raccoons.
This study marked the inaugural investigation into the influence of incubation temperature on leatherback hatchling performance within the United States. Prior research primarily centered on green and loggerhead sea turtles. Detailed by the Endangered Species Research journal, the findings unveiled a substantial connection between nest temperature and various crucial parameters. Notably, hatchling morphology, performance, and nest success were all significantly affected by incubation temperature. Interestingly, mid-season hatchlings exhibited greater mass compared to their late-season counterparts.
Researchers meticulously gathered data by deploying temperature loggers in 13 leatherback turtle nests along a 9.6-kilometer stretch of Juno Beach, covering early, middle, and late South Florida nesting seasons. The correlation between nest incubation temperatures and hatching success, emergence success, hatchling morphology, and locomotor performance was scrutinized. These temperature gradients produced fascinating outcomes: lower temperatures resulted in longer hatchlings, while higher temperatures yielded hatchlings with thicker body depths. Additionally, flipper length exhibited temperature-dependent variations.
Locomotor performance did not mirror the correlations observed in hatching and emergence success. Regardless of incubation temperatures, leatherback hatchlings crawled at similar speeds. This suggests that other factors, perhaps related to body morphology, are pivotal in influencing terrestrial performance. These findings underscore the importance of identifying the “sweet spot” temperature for incubation, as it significantly impacts leatherback sea turtle hatchlings’ success rates and physical performance. Furthermore, they shed light on the potential ramifications of rising nest temperatures on their survival, emphasizing the urgency of addressing climate change-induced threats to this vulnerable species.
References
- Florida Atlantic University. (2023, September 7). First US study of nest temperature impacts on leatherback hatchlings. Phys.Org. https://phys.org/news/2023-09-temperature-impacts-leatherback-hatchlings.html
- Seaman, H., & Milton, S. (2023). Impacts of nest temperatures on leatherback reproductive success, hatchling morphology, and performance in South Florida. Endangered Species Research, 51, 305–317. https://doi.org/10.3354/esr01261
