Feeding Practices, Body Condition, and Estimated Energy Provision in Rescued Loggerhead Sea Turtles (Caretta caretta) at a Mediterranean Rehabilitation Center: A Three-Year Retrospective Study.

Abstract

The loggerhead sea turtle [Caretta caretta (Linnaeus, 1758)] is the most frequently stranded marine turtle in the Mediterranean and faces substantial anthropogenic threats. No species-specific nutritional guidelines currently exist for its rehabilitation. This retrospective study analyzed feeding practices, feed acceptance, and body weight change in 20 C. caretta admitted to a Mediterranean rescue center between 2020 and 2023. Estimated target gross energy provision, modeled from body-weight percentages, ranged from 11.1 to 22.2 kcal/kg body weight/day under a squid-only regimen and from 18.1 to 36.2 kcal/kg body weight/day under a mixed regimen, with corresponding target dry matter provision of 2.7-5.4 and 3.1-6.2 g/kg body weight/day. Energy actually consumed, derived from recorded daily rations, fell within the modeled target range for both regimens, the daily ration corresponding to a median of 2.01% of body weight. Dietary variety was positively associated with weight change, but this did not persist after correction for multiple comparisons and is reported as hypothesis generating. Overall, 90% of animals were released, a descriptive outcome that the retrospective design does not allow to be attributed to feeding management. Thawed squid (Loligo vulgaris) was the most frequently offered and the most readily accepted feed item. These findings offer a preliminary, hypothesis-generating framework for future prospective nutritional studies of this species in Mediterranean rehabilitation settings.