Long-distance oceanic movement of a solitary dugong (Dugong dugon) to the Cocos (Keeling) Islands

Abstract

In this paper, we report on the arrival of a small (2 m long) male dugong (Dugong dugon) to the Cocos (Keeling) Islands (12° 12' S, 96° 54' E), Indian Ocean. The dugong arrived in June 2002 after travelling more than 1,000 km across deep open ocean, during which time it would have been vulnerable to predation and presumably unable to feed. This is the longest recorded dugong movement and demonstrates that dugongs have the capacity to make long-distance oceanic movements to colonise distant, unoccupied locations. The solitary dugong has remained at the Cocos Islands for at least four years and exhibits unusual habitat use and behaviour; it frequently occupies deep water on the edge of the coral reef and interacts with SCUBA divers.