Life after death: behaviour of multiple shark species scavenging a whale carcass.

A drone was used to study the richness and behaviour of scavengers attracted to the carcass of a sperm whale (Physeter microcephalus) in Seychelles, Western Indian Ocean. Over 30 sharks of 3 species (tiger shark Galeocerdo cuvier , bull shark Carcharhinus leucas and tawny nurse shark Nebrius ferrugineus) were recorded scavenging on the carcass. Tiger sharks dominated the scavenging, but with no evidence of agonistic behaviours or hierarchy, and may have facilitated scavenging by other species. Drone use allowed the analysis of such behaviours without observer influence, providing new insights into communal scavenging events. For the first time, multiple tiger, bull and nurse sharks were all recorded feeding on the same sperm whale carcass. Moreover, the event was observed using a drone, meaning that the sharks were undisturbed by humans and exhibited natural behaviour. Contrary to expectation, there was no aggression between any of the sharks. Instead, they all fed calmly alongside each other during this communal scavenging event. [ABSTRACT FROM AUTHOR]