New distribution records of the coconut crab (Birgus latro) in eastern Polynesia on Oeno Atoll, Henderson Island, and Ducie Atoll, Pitcairn Islands

Coconut (or robber) crabs (Birgus latro) are found throughout the Indo-Pacific, including as far east as the Gambier Islands, French Polynesia, though the eastern edge of their range is poorly defined. Here, we document narratives and occurrences of coconut crabs on Oeno Atoll, Henderson Island, and Ducie Atoll in the Pitcairn Islands, which extends the currently known eastern limit of coconut crabs’ range by >600 km.

Crabs are not abundant on the islands, but suitable habitat and prey are available, so larger populations may be present, particularly on Henderson Island. Edge-of-range populations are often the most susceptible to pressures, but the remoteness of the Pitcairn Islands may shield coconut crabs from threats present elsewhere in the Indo-Pacific region.