Homing ability of young lemon sharks, Negaprion brevirostris

Abstract

We carried out the first experimental study testing an elasmobranch's ability to return home. We displaced juvenile lemon sharks,Negaprion brevirostris, 4-16 km from their observed home ranges at Bimini Islands, Bahamas during daylight and at night. We tracked all sharks except one back to the Bimini Islands and most returned to their home ranges observed before displacement. Even sharks displaced to a site closer to another island with suitable habitat for young lemon sharks returned to their home ranges at Bimini Islands. Sharks displayed a preferred compass direction (PCD) toward the east as their first swimming direction after release, suggesting an innate sense of direction. This bearing was followed shortly afterwards by a home-oriented direction. Swimming speeds prior to reaching shore were approximately twice as fast than the usual cruising speed reported for juvenile lemon sharks. The return of young (0-2 years), inexperienced sharks to their original home range indicate high site fidelity and an ability to home. © Springer 2005.