Historical Records of Loggerhead Sea Turtle (Caretta caretta) Nesting at Tortuguero, Costa Rica

Abstract.— Costa Rica is considered a hot spot for biodiversity and wildlife conservation in Central America, and sea turtles are a good example of this. Largely distributed along both the Caribbean and Pacific coast, adult females of five of the seven extant sea turtle species select beaches on both coasts as their breeding sites. Although Green Sea Turtles (Chelonia mydas), Leatherback Sea Turtles (Dermochelys coriacea), Hawksbill Sea Turtles (Eretmochelys imbricata), and Olive Ridley Sea Turtles (Lepidochelys olivacea) have been extensively studied in Costa Rica, little information regarding Loggerhead Sea Turtles (Caretta caretta) is available. Thus, we present an exhaustive data record of every Loggerhead encountered at Tortuguero beach (northeastern Caribbean coast of Costa Rica) over the past 60 yr. We collected Loggerhead nesting data between 1957 and 2021 through daytime and nocturnal monitoring activities. We documented 14 Loggerhead Sea Turtle nesting attempts between 1957 and 2021 at Tortuguero. Among them, seven nested successfully, four did not lay eggs, and one's fate is unknown. Additionally, two turtles were killed by jaguars. Mean minimum curve carapace length (CCLmin) measurements for Loggerheads was 98.2 ± 3.7 cm (range, 90.0–101.4 cm). Finally, we found that every encounter occurred between April and July, which coincides with the Loggerhead nesting season in the Northwest Atlantic. Our study is the first assessment of Loggerhead Sea Turtles nesting in Costa Rica, bringing to light new records for this species in the Caribbean Sea.