No detectable effect of limited manual nest excavation on hatching and emergence success in loggerhead sea turtles ( <i>Caretta caretta</i> )

The hatching success of loggerhead sea turtles (Caretta caretta) is a key parameter in conservation and monitoring programmes. While numerous studies have examined the effects of environmental and anthropogenic factors on hatching success, the potential impact of nest detection methods used during monitoring has received limited attention. In particular, manual excavation to confirm the presence of eggs is widely practiced, yet its effect on hatching success remains debated. The study tested whether limited manual excavation performed solely for nest detection affects hatching success on Belek Nesting Beach (Antalya, Türkiye) during the 2020 nesting season. A total of 100 nests were monitored, including 50 nests confirmed by minimal manual excavation and 50 identified without excavation. Hatching and emergence success, duration of incubation, and nest distances to the sea and vegetation were recorded and statistically compared between the two groups. Mean hatching success was 80.7% in manually excavated nests and 84.2% in non-excavated nests. Statistical analyses revealed no significant difference in hatching success between the two nest detection methods (t = –0.849, p = 0.398). Emergence success did not differ significantly between manually excavated and non-excavated nests (t = −1.02, p = 0.312). Similarly, incubation duration and spatial nest characteristics did not differ significantly between groups. Our results indicate that limited manual excavation conducted solely for nest detection did not result in a detectable effect on hatching or emergence success under the conditions examined. These findings support the continued use of controlled manual excavation as a low-impact nest detection method in sea turtle monitoring programmes, provided that disturbance is minimised and best-practice protocols are followed. The study contributes empirical evidence to the evaluation of monitoring-related interventions in loggerhead sea turtle conservation.