Pauline Baas1, Tom van der Valk1, Linda Vigilant2, Urbain Ngobobo3, Escobar Binyinyi3, Radar Nishuli4, Damien Caillaud3,5, Katerina Guschanski1. 1. Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden. 2. Primatology Department, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, Germany. 3. Dian Fossey Gorilla Fund International, 800 Cherokee Avenue, Atlanta, Georgia. 4. Institut Congolais pour la Conservation de la Nature, N4, Réserve de Faune à Okapis, Democratic Republic of Congo. 5. Department of Anthropology, University of California, Davis, One Shields Ave, Davis, California.
Abstract
OBJECTIVES: The critically endangered Grauer's gorilla (Gorilla beringei graueri) has experienced an estimated 77% population decline within a single generation. Although crucial for informed conservation decisions, there is no clear understanding about population structure and distribution of genetic diversity across the species' highly fragmented range. We fill this gap by studying several core and peripheral Grauer's gorilla populations throughout their distribution range. MATERIALS AND METHODS: We generated genetic profiles for a sampling of an unstudied population of Grauer's gorillas from within the species' core range at 13 autosomal microsatellite loci and combined them with previously published and newly generated data from four other Grauer's gorilla populations, two mountain gorilla populations, and one western lowland gorilla population. RESULTS: In agreement with previous studies, the genetic diversity of Grauer's gorillas is intermediate, falling between western lowland and mountain gorillas. Among Grauer's gorilla populations, we observe lower genetic diversity and high differentiation in peripheral compared with central populations, indicating a strong effect of genetic drift and limited gene flow among small, isolated forest fragments. DISCUSSION: Although genetically less diverse, peripheral populations are frequently essential for the long-term persistence of a species and migration between peripheral and core populations may significantly enrich the overall species genetic diversity. Thus, in addition to central Grauer's gorilla populations from the core of the distribution range that clearly deserve conservation attention, we argue that conservation strategies aiming to ensure long-term species viability should include preserving peripheral populations and enhancing habitat connectivity.
OBJECTIVES: The critically endangered Grauer's gorilla (Gorilla beringei graueri) has experienced an estimated 77% population decline within a single generation. Although crucial for informed conservation decisions, there is no clear understanding about population structure and distribution of genetic diversity across the species' highly fragmented range. We fill this gap by studying several core and peripheral Grauer's gorilla populations throughout their distribution range. MATERIALS AND METHODS: We generated genetic profiles for a sampling of an unstudied population of Grauer's gorillas from within the species' core range at 13 autosomal microsatellite loci and combined them with previously published and newly generated data from four other Grauer's gorilla populations, two mountain gorilla populations, and one western lowland gorilla population. RESULTS: In agreement with previous studies, the genetic diversity of Grauer's gorillas is intermediate, falling between western lowland and mountain gorillas. Among Grauer's gorilla populations, we observe lower genetic diversity and high differentiation in peripheral compared with central populations, indicating a strong effect of genetic drift and limited gene flow among small, isolated forest fragments. DISCUSSION: Although genetically less diverse, peripheral populations are frequently essential for the long-term persistence of a species and migration between peripheral and core populations may significantly enrich the overall species genetic diversity. Thus, in addition to central Grauer's gorilla populations from the core of the distribution range that clearly deserve conservation attention, we argue that conservation strategies aiming to ensure long-term species viability should include preserving peripheral populations and enhancing habitat connectivity.
Authors: Kate McGrath; Amandine B Eriksen; Daniel García-Martínez; Jordi Galbany; Aida Gómez-Robles; Jason S Massey; Lawrence M Fatica; Halszka Glowacka; Keely Arbenz-Smith; Richard Muvunyi; Tara S Stoinski; Michael R Cranfield; Kirsten Gilardi; Chantal Shalukoma; Emmanuel de Merode; Emmanuel Gilissen; Matthew W Tocheri; Shannon C McFarlin; Yann Heuzé Journal: Proc Biol Sci Date: 2022-02-23 Impact factor: 5.530