A study published today in Nature Communications demonstrates that decades of human-linked foraging, such as deliberate feeding and scavenging from boats, have fundamentally reshaped the social networks of wild bottlenose dolphins in Sarasota Bay, Florida. The research, led by scientists at the University of Florida, tracked more than 200 individuals across 25 years using extensive behavioral observations and genetic sampling.
These findings highlight a rarely documented consequence of anthropogenic influence: not just individual behavioral shifts, but systemic alteration of a species' social fabric. Unlike direct harm such as boat strikes or pollution, this change operates at a structural level, as dolphins that regularly interact with humans form distinct cliques with different alliance patterns less reliant on maternal lineages.
The data reveal that dolphins with higher rates of human interaction—those repeatedly provisioned by people or habituated to fishing activity—show significantly reduced kin-based associations compared to wild-feeding peers. The effect persisted even after controlling for age, sex, and relatedness, suggesting a robust causal pathway from human provisioning to social rewiring.
Long-term implications remain uncertain, but scientists warn that altered social networks could impair information sharing about food sources or predator avoidance. Critics of the study note that correlation does not prove causation, and that natural food availability or pre-existing social disruption might explain some results.