The importance of small-island populations for the long-term survival of endangered large-bodied insular mammals
Abstract
Island populations of large vertebrates have experienced higher extinction rates than mainland populations over long timescales due to demographic stochasticity, genetic drift, and inbreeding. While being more susceptible to extinction and as such potentially targeted for conservation interventions such as genetic rescue, small-island populations can experience relatively less anthropogenic habitat degradation than those on larger islands. Here, we determine the consequences and conservation implications of long-term isolation and recent human activities on genetic diversity of island populations of two forest-dependent mammals endemic to the Wallacea archipelago: the anoa ( Bubalus spp.) and babirusa ( Babyrousa spp.). Using genomic analyses and habitat suitability models, we show that, compared to closely related species, populations on mainland Sulawesi exhibit low heterozygosity, high inbreeding, a high proportion of deleterious alleles, and experience a high rate of anthropogenic disturbance. In contrast, populations on smaller islands occupy higher-quality habitats, possess fewer deleterious mutations despite exhibiting lower heterozygosity and higher inbreeding. Site frequency spectra indicate that these patterns reflect stronger, long-term purging in smaller-island populations. Our results thus suggest that conservation efforts should focus on protecting small-island high-quality habitats and avoiding translocations from mainland populations. This study highlights the crucial role of small offshore islands for the long-term survival of Wallacea’s iconic and indigenous mammals in the face of development on the mainland.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (27)
Sabhrina Gita Aninta
School of Biological and Behavioural Sciences, Queen Mary University of London
Rosie Drinkwater
Alberto Carmagnini
Nicolas J. Deere
Durrell Institute of Conservation and Ecology, University of Kent
Dwi Sendi Priyono
Department of Tropical Biology, Faculty of Biology, Universitas Gadjah Mada
Noviar Andayani
Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Indonesia
Nurul L. Winarni
Faculty of Mathematics and Natural Sciences, Research Center for Climate Change, Universitas Indonesia
Jatna Supriatna
Matteo Fumagalli
School of Biological and Behavioural Sciences, Queen Mary University of London
Greger Larson
Peter H. A. Galbusera
Antwerp Zoo Centre for Research and Conservation, Royal Zoological Society of Antwerp
Alastair Macdonald
Royal (Dick) School of Veterinary Studies, University of Edinburgh
Deborah Greer
School of Biological and Behavioural Sciences, Queen Mary University of London
Kusdiantoro Mohamad
Division of Anatomy Histology and Embryology, School of Veterinary Medicine and Biomedical Sciences, Institut Pertanian Bogor (IPB) University
Wahono Esthi Prasetyaningtyas
Division of Anatomy Histology and Embryology, School of Veterinary Medicine and Biomedical Sciences, Institut Pertanian Bogor (IPB) University
Abdul Haris Mustari
Department of Forest Resources Conservation, Faculty of Forestry and Environment, Institut Pertanian Bogor (IPB) University
John Lewis Williams
Department of Animal Science, Food and Nutrition, Università Cattolica del Sacro Cuore
Ross Barnett
Durham Evolution and Ancient DNA, Department of Archaeology, University of Durham
Darren Shaw
Royal (Dick) School of Veterinary Studies, University of Edinburgh
Gono Semiadi
Research Centre for Biosystematics and Evolution, National Research and Innovation Agency (Badan Riset dan Inovasi Nasional)
James Burton
International Union for Conservation of Nature and Natural Resources, Species Survival Commission (IUCN SSC) Asian Wild Cattle Specialist Group
David J. I. Seaman
Durrell Institute of Conservation and Ecology, University of Kent
Maria Voigt
Durrell Institute of Conservation and Ecology, University of Kent
Matthew J. Struebig
Durrell Institute of Conservation and Ecology, University of Kent
Selina Brace
Stephen J. Rossiter
Laurent Frantz