Social Associations
The ongoing Photo-ID and long-term monitoring work has enabled to develop the first social network analysis (SNA) of tiger sharks (Galeocerdo cuvier) in Fuvahmulah. Although tiger sharks are often considered solitary apex predators, repeated co-occurrence patterns captured across dives, baited sites, and cleaning stations reveal a far more complex picture of how individuals use shared space.
Tiger sharks (Galeocerdo cuvier) are typically described as solitary, wide-ranging apex predators, yet growing evidence suggests that they exhibit far more complex spatial and social dynamics than previously assumed. In locations where prey, environmental conditions, and anthropogenic factors create predictable hotspots, tiger sharks may repeatedly encounter the same individuals, forming loosely structured social assemblages. Understanding these associations is essential not only for behavioural ecology but also for conservation, as social structure can influence vulnerability to fisheries, disease transmission, and population resilience.
Fuvahmulah offers a rare setting where a resident population of tiger sharks can be reliably observed year-round. The consistent presence of identifiable individuals enables a unique opportunity to quantify social relationships within a typically “non-social” species. Using individual photo-identification and repeated observations over time, social network analysis (SNA) provides a framework to investigate patterns of co-occurrence, preferred associations, and the roles that specific individuals play within the network.
Using temporal co-sightings, individual identity records, and behavioural observations, the SNA maps how frequently specific sharks are encountered together, how often they overlap spatially, and whether certain individuals act as key connectors within the local population. This approach allows us to examine:
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Association strength between individuals based on repeated co-occurrence, calculated with the Half-weight Index
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Sex-, or Size-dependent formation (e.g., loose clusters of sharks that tend to appear together more often than expected by chance)
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Temporal patterns, including whether associations persist across seasons or are tied to specific events or months.
Early results show that Fuvahmulah’s tiger sharks do not form stable “social groups” in the classical sense, but they do exhibit non-random association patterns. Some individuals, especially long-term residents, large females, interact more frequently with particular sharks, forming strong, consistent social ties. These patterns may be shaped by site fidelity, habitat preference, age class, or sex-specific behaviours.
By combining SNA with Photo-ID, movement data, and behavioural footage, in the future, we aim to gain a more holistic understanding of how tiger sharks structure their use of Fuvahmulah’s coastal and pelagic habitats. This network-based perspective is vital for conservation, as it highlights which individuals are central to local connectivity, how human presence may influence association patterns, and how provision enhances social ties between solitary individuals.