Ecological connectivity between Gabon's protected areas

Abstract

This thesis investigates wildlife connectivity in Gabon using large‑scale camera‑trap data to inform national conservation policy and guide the creation of ecological corridors. Building on the country’s commitment to expand protected and conserved areas under the 30×30 framework, the thesis integrates multi‑species occupancy modelling, landscape permeability analysis, and policy evaluation to produce an evidence‑based corridor‑design strategy. Chapter 2 examines how camera‑trap placement strategies influence biodiversity assessments. Using a 36 km² grid, three deployment protocols, random, semi‑random, and optimized, are compared for five key large mammals. Optimised placement along forest and skidder trails substantially increased capture rates, naïve occupancy, and detection probabilities for forest elephants, leopards, African golden cats, and chimpanzees, highlighting the need for transparent, standardised survey design to ensure comparability across sites and over time. Chapter 3 integrates detection histories from eleven nationwide surveys (2015–2021; 941 stations; 49,303 trap‑days) to develop multi‑scale occupancy models for four focal species. Forest cover, productivity, rugged terrain, and distance to villages consistently structured occupancy patterns. These species‑level models were combined into a national conductance surface, and CircuitScape omnidirectional current‑flow analyses were used to map wildlife permeability. High‑permeability linkages were identified between major protected areas, notably Loango–Moukalaba‑Doudou, Waka–Lopé, and Lopé–Ivindo. Chapter 4 applies these models to delineate ecological corridors in two priority regions (southwest and northeast). Corridor routing incorporated planned protected areas, HCV forests, land‑use constraints, and community considerations. Leopard occupancy, showing the strongest correlation with national connectivity, was identified as the most suitable proxy for monitoring long‑term corridor functionality. Chapter 5 highlights the policy relevance of camera‑trap by‑catch data for updating IUCN categories, informing national land‑use planning, and confirming corridor choices for ape taxa. Chapter 6 synthesises findings and outlines future directions for integrating connectivity science into Gabon’s conservation strategy.