Climate change is impacting sea turtles worldwide with the effects varying between species and populations. For example, rising temperatures have variable effects on the duration of the inter-nesting period (IP)—the time between two consecutive nests during a single nesting season. Specifically, a negative correlation between water temperature and IP has been reported in green (Chelonia mydas), hawksbill (Eretmochelys imbricata), and loggerhead (Caretta caretta) turtles. In contrast, previous studies have shown no correlation for olive ridley turtles (Lepidochelys olivacea). Here, we assessed whether this lack of a correlation in olive ridley turtles was a product of the small sample size used in previous studies (nmax=11). We used capture-mark-recapture data over 14 years to calculate the IP of olive ridley turtles (n=96) nesting on two different beaches in Costa Rica. Next, we calculated mean sea surface temperature (SST) during each IP within estimated inter-nesting areas (225 km2), as inferred from previous olive ridley telemetry studies, and using data from NASA’s multi-scale ultra-high-resolution sensor. Mean (±SD) IP was 22.5±6.0d (range: 13-41 d) and mean SST was 28.0±0.6℃ (range: 26.1-29.5 ℃). We observed a statistically significant negative relationship between SST and IP suggesting that elevated temperatures at inter-nesting habitats influence the phenology of olive ridley turtles as previously observed in other hard-shelled sea turtle species. Thus, we postulate that elevated temperatures due to climate change may influence the timing of nesting seasons for solitary nesting olive ridley turtles and may even alter timing of the olive ridley mass nesting aggregations known as arribadas

Funding over the years was provided by the Earthwatch Institute, the Schrey Distinguished Professorship of Purdue University Fort Wayne, the Betz Chair Endowment of Drexel University, the AZA Sea Turtle SAFE Program, Virginia Aquarium Camp; Marine Science Center, North Carolina Aquariums, South Carolina Aquarium, the Florida Aquarium and The Leatherback Trust. NJR was funded by the Spanish government (AEI) through the Ramon y Cajal postdoctoral program (#RYC2021-034381-I). Support to ICM was provided via the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) and funded by the Agencia Estatal de Investigación (AEI) 10.13039/501100011033

Peer reviewed