Adult female whale sharks make long-distance movements past Darwin Island (Galapagos, Ecuador) in the Eastern Tropical Pacific

Most previous studies on whale shark movements have been on immature sharks. Here, we present tracking data for large females that we tagged at the Galapagos Islands, where they occur seasonally. We conducted fieldwork at Darwin Island (1.67, 92.0 degrees W) from July to October in 2011 and in 2012. We often saw individual sharks several times on a particular day, but rarely saw them again more than 2 days later after they were first sighted. We tagged 39 female whale sharks, 36 of which were between 8 and 12 m long. We tracked 27 sharks for 9-176 days (median = 47 day). Sharks tagged in July moved west into the open ocean, whereas those tagged in September and October moved toward the coast of South America. They travelled between 49 and 2747 km from Darwin (median = 1296 km), at about 38 km day(-1) (median rate). We observed five of those sharks later at various times at Darwin Island after >1 month absence, by photo-identification (n = 2) or satellite track (n = 3). Tracks that lasted through December ended along the continental shelf break of northern Peru. We show return movements of individuals through Darwin after moving large distances into the open ocean and establish connectivity with mainland Ecuador and Peru.