Applying best practice to feasibility assessment and strategic planning for great ape translocation: a case study of Grauer's gorilla (Gorilla beringei graueri)

Abstract

We outline the feasibility and risk assessments that are essential prerequisites to conservation translocation of great apes, while upholding the precautionary principle to avoid harms to conspecifics, sympatric taxa and ecosystems. As part of a strategic planning process, we addressed key questions on the costs and benefits of a translocation of Grauer's gorillas in Democratic Republic of Congo. We reviewed published and gray literature to compile data on Grauer's gorilla ecology and potential release sites in the subspecies' geographic range. Taking into account ecological dimensions of the habitats, impacts on conspecifics, sympatric great apes and other wildlife, and existing threats, we formulated recommendations on whether and where translocation could benefit conservation of this taxon. We concluded that one site assessed is compatible with key IUCN criteria. At Mt. Tshiaberimu in Virunga National Park, the resident Grauer's gorilla population is non-viable, no sympatric great ape species is present and the site is actively protected against poaching and habitat encroachment. Conservation translocations are widely used for species recovery; however, detailed accounts of the analyses and planning required to adhere to IUCN best practice are rare. Our approach enabled evidence-based determination of feasibility despite some initial information gaps. The process is widely applicable and could encourage improved compliance with IUCN guidelines when risks to wild conspecifics might be high, yet ecological knowledge of the target population is limited. The Grauer's Gorilla Conservation and Reinforcement Project is a partnership between the Gorilla Rehabilitation and Conservation Education Center, Virunga National Park and Re:wild.