Biology subjects

Reischig, T.

Publications and source records attributed to Reischig, T..

3 recordsLinked to original sources

bioRxiv2026

Habitat-specific environmental characteristics are associated with the movement of male and female loggerhead sea turtles

Linking animal movements to environmental drivers is essential for understanding ecological processes and anticipating species responses to climate change. We investigated habitat-specific movements in a globally significant aggregation of loggerhead turtles (Caretta caretta) nesting in Cabo Verde. Satellite tags on 15 adults (12 females, 3 males) provided multi-year tracks spanning breeding, migration, and foraging habitats. Movements and phenology differed by habitat. During the breeding season, females used either coastal areas, remaining within [~]20 m depth, or undertook long looping forays up to 360 km. Males showed two strategies: two remained resident in Cabo Verde waters, including Fra, the largest male tracked (Curved carapace length of 105 cm compared with a male mean of 90.7 {+/-} 10.3 cm), while the third migrated annually to distant foraging grounds and returned ahead of the subsequent breeding season. In foraging habitats, turtles adopted neritic or oceanic strategies: neritic turtles remained localised in warm, productive waters, whereas oceanic turtles ranged widely in deeper, less productive areas. Time- and space-shift analyses showed that oceanic foragers used intermediate sea surface temperature and chlorophyll-a conditions relative to nearby or temporally shifted alternatives, consistent with movement within a thermal-trophic trade-off. Together, these results show how sex, body size, and energy balance drive habitat-specific movement dynamics in a changing ocean.

zoology↗

bioRxiv2025

The migration of an expanding sea turtle population alters the structure of marine megafauna communities

Interactions shape community structures, yet the impact of large migratory influxes on communities, particularly marine ones, remains elusive. Using drone surveys, we investigated changes of marine megafauna communities (e.g., sharks, rays), during the mass migration of loggerhead sea turtles (Caretta caretta) in Cabo Verde, one of the largest, and growing, rookeries globally and a biodiversity hotspot. In high nesting density areas, with over 6,000 turtles detected in-water at the seasons peak, the community structured with sharks distributing between the turtles and the coastline. In low-density areas ([~]500 turtles), no structuring was detected. After the seasons peak, increased shark abundance and shoreward movement suggest they anticipate a nutrient pulse from emerging hatchlings. Our results highlight the role of sea turtle abundance in structuring marine communities, both as a high-quality food resource (hatchlings) and a likely non-consumable species (adults). Overall, we show the significant impact of migratory species on marine megafauna communities.

ecology↗

bioRxiv2020

Genetics survey reveals colonization and philopatry of the loggerhead sea turtles across geographic scales

AimUnderstanding the processes that underlie the distribution of genetic diversity in endangered species is a goal of modern conservation biology. Specifically, how population structure affects genetic diversity and contributes to a species adaptive potential remain elusive. The loggerhead sea turtle (Caretta caretta) faces multiple conservation challenges due to its migratory nature and philopatric behaviour. LocationsAtlantic Ocean, Cabo Verde, island of Boavista MethodsHere, using 4207 mtDNA sequences, we analysed the colonisation patterns and distribution of genetic diversity within a major ocean basin (the Atlantic), a regional rookery (Cabo Verde Archipelago) and a local island (Island of Boavista, Cabo Verde). ResultsHypothesis-driven population genetic models suggest the colonization of the Atlantic has occurred in two distinct waves, each corresponding to major mtDNA lineages. We propose the oldest lineage entered the basin via the isthmus of Panama and sequentially established aggregations in Brazil, Cabo Verde and in the area of USA and Mexico. The second lineage entered the Atlantic via the Cape of Good Hope, establishing colonies in the Mediterranean Sea, and from then on, re-colonized the already existing rookeries of the Atlantic. At the Cabo Verde level, we reveal an asymmetric gene flow maintaining links across nesting groups despite significant genetic structure amongst nesting groups. This structure stems from female philopatric behaviour which could further be detected by weak but significant structure amongst beaches separated by only a few kilometres on the island of Boavista. Main conclusionTo explore demographic processes at diverse geographic scales improves understanding the complex evolutionary history of highly migratory philopatric species. Unveiling the past facilitates the design of conservation programmes targeting the right management scale to maintain a species adaptive potential and putative response to human-induced selection.

evolutionary biology↗