Light Sandy Beaches Favour Hatching Success and Best Hatchling Phenotype of Loggerhead Turtles

We conducted a 5-year field (2017–2021) and laboratory study of the relationship between type substrate hatching success, embryonic development, quality hatchlings in loggerhead turtle nests. Our site, island Maio archipelago Cabo Verde, one world’s largest nesting colonies, displays marked heterogeneity sand colouration, with dark, mixed, light sandy beaches. experimentally incubated eggs, comparing different substrates under standard temperature humidity conditions. Females nest all types without preference. However, both experimental revealed significant difference success depending on substrate. Substrate volcanic origin, dark colour, lower amount calcium carbonate, had (HS; 30.3 ± 20.2%) compared to mixed (HS = 46.1 26.5%) or 78.1 18.2%) colour. Eggs that was light-coloured, larger grain size higher carbonate concentration, produced significantly more offspring. Incubation temperatures were substrate, which partially explains this sand. incubation controlled consistently showed Thus, we found not only temperature, but also specific characteristics each determine success. The main predator eggs (the ghost crab Ocypode cursor ) no differences abundance types. results indicate site selection beaches even within same beach conditions affects hatchling physical condition, subsequently reproductive female. can inform conservation programmes management optimise adaptive future scenarios rising global temperatures.