# Correlations between local geoclimatic variables and hatchling body size in the sea turtles Caretta caretta and Chelonia mydas

## TL;DR

This study explores how precipitation during nesting season affects the body size of loggerhead and green sea turtle hatchlings across 37 beaches.

## Contribution

The study reveals distinct correlations between precipitation and hatchling body size in loggerhead and green turtles, with new insights into regional environmental impacts.

## Key findings

- Loggerhead hatchling body size is negatively correlated with precipitation.
- Green turtle hatchling carapace length and width are positively correlated with precipitation.
- Precipitation's strongest effect on loggerhead turtles occurs mid-incubation in Cabo Verde.

## Abstract

It has been widely demonstrated that air and sand temperatures influence the anatomy of sea turtle hatchlings. We examined the impact of precipitation during the nesting season on the hatchling body size of loggerhead and green turtles from 37 beaches worldwide. Longitudinal data collected between 2012 and 2018 from Florida (US) and from a sample on Bõa Vista Island (Cabo Verde) carried out in 2019 showed that loggerhead body size at hatching was negatively correlated with precipitation, while precipitation was not correlated with hatchling body size in green turtles. A meta-analysis revealed that precipitation is positively correlated with hatchling mass in loggerhead turtles, while it is positively correlated with straight carapace length and width in green turtle hatchlings. The strongest influence of precipitation was found in the middle of the incubation period of loggerhead turtles in Cabo Verde, and we posit that this is due to an increase in the uptake of water for embryonic growth. These findings highlight the great importance of understanding the correlated effects of regional environmental variables, such as precipitation, on the development of sea turtle hatchlings and will have an impact on the evaluation of ongoing conservation and climate change discussions.

The online version contains supplementary material available at 10.1186/s12862-024-02290-7.