76 3.2.2 Flipper tag recoveries and CMR Capture-mark-Recapture (CMR) techniques have been applied to evaluate marine turtles' spatial dispersion and population boundaries for many decades (Eckert and Eckert 1989; Read et al. 2014; Hancock et al. 2019; Siegwalt et al. 2020; Perez et al. 2022). It consists in individually identifying each turtle met for the first time by using a distinctive tag and to record every subsequent encounter afterward. Here, we used it to test the hypothesis that loggerhead females nest indifferently at the RP and the GLS areas over separate breeding seasons. This assumes that individuals tagged in one of these areas would have a similar probability of being recaptured at both areas in subsequent seasons. Tag deployments and data collection were performed on nesting females encountered during nocturnal beach patrols. Individuals were either considered as captures (C) if observed without a tag, in which case they were assigned one, or as recaptures (R) if they were tagged from previous seasons. In this study, titanium tags have been used as their longevity generally exceeds 10 years (Limpus 1992). They are implanted on the trailing edge of the front left and/or right flipper after successful oviposition (or on the way down to the ocean in case of an unsuccessful nesting attempt) to minimize female disturbance (Balazs 1999; Broderick and Godley 1999). The use of this technique requires the registration of a large number of individuals over several years of effort to be effective, as there is often a low recapture rate in the early stages of the protocol implementation (Limpus 1992; Limpus et al. 1992; Balazs 1999; Perez et al. 2022). We benefited from the dataset collected on the RP nesting area, which holds a significant number of identified females since the establishment of a long term, daily survey ongoing since the 2006-07 nesting season (Barbier et al. 2023). On the other hand, CMR surveys have been conducted on the islets of the GLS nesting area since the 2016-17 nesting season for the purpose of this study. In order to test females’ nest-site fidelity over multiple breeding seasons, we have considered the proportion of recaptured individuals at the RP and the GLS nesting areas over the 201617 to 2022-23 nesting season period. If they do not differ significantly, we will consider that nesting females tend to use both nesting areas indifferently over time. Otherwise, we will assume that they show a strong fidelity to their nesting site, resulting in a low to nonexistent connectivity level between both nesting areas.
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