The islands of Darwin and Wolf in the Galapagos archipelago, Cocos Island and Malpelo Island have all been identified as congregating zones for this species for a large part of the year. In these places it is common to see schools of hundreds of hammerhead sharks, mostly adult females, near the coasts during the daytime. These sharks generally disperse at night to feed on squid in open water areas.
Migration between islands in the Galapagos archipelago
There is frequent movement between the islands of Darwin and Wolf located in the north of the archipelago, and intensive use of the open waters around them, extending even to an area of underwater mounts outside the limits of the Galapagos Marine Reserve. At certain times of year, some sharks make short journeys back and forth to Roca Redonda, in the west of the archipelago.
Connectivity between the Galapagos Islands, Cocos Island and Malpelo Island
In March, 2007, two female hammerhead sharks were recorded simultaneously at Cocos Island 14 days after last being recorded off Darwin Island, where they were first tagged. They were both detected briefly, and after a month one of them returned to Darwin. A shark tagged at Malpelo Island travelled to Cocos Island and then on to Galapagos, where it stayed close to Darwin and Wolf over several months. In total, 11 movements of hammerhead sharks have been detected between the three marine reserves. MigraMar is working to establish the movement patterns between these areas and the large juvenile areas off the coasts of Panama and Costa Rica.