Chapter 23 - Floreana and Pinta Islands: Restoring tortoise populations through lost lineage recovery

Abstract

The giant tortoise species of Floreana (Chelonoidis niger) and Pinta (C. abingdonii) Islands are extinct. Efforts to restore tortoise populations on both islands prioritize ecosystem and island restoration through the return of giant tortoises and their role as ecological engineers. This chapter describes the landscape and history of Pinta and Floreana Islands, including the exploitation and eventual extinction of their saddleback tortoise species and the arrival, impact, control, and eradication of introduced mammals. The chapter describes the discovery of tortoises with mixed ancestry on Wolf Volcano on northern Isabela Island, including some with Floreana tortoise ancestry and fewer with Pinta tortoise ancestry. This discovery jump-started efforts to restore tortoise populations on both islands with tortoises with partial ancestry of the extinct species. The chapter ends with a discussion of island restoration through the replacement of extinct tortoise species using lost lineages, including planning efforts to ensure rapid population growth and genetic diversity.