BioScience Advance Access published July 27, 2016 Viewpoint Saving the World’s Terrestrial Megafauna WILLIAM J. RIPPLE, GUILLAUME CHAPRON, JOSÉ VICENTE LÓPEZ-BAO, SARAH M. DURANT, DAVID W. MACDONALD, PETER A. LINDSEY, ELIZABETH L. BENNETT, ROBERT L. BESCHTA, JEREMY T. BRUSKOTTER, AHIMSA CAMPOS-ARCEIZ, RICHARD T. CORLETT, CHRIS T. DARIMONT, AMY J. DICKMAN, RODOLFO DIRZO, HOLLY T. DUBLIN, JAMES A. ESTES, KRISTOFFER T. EVERATT, MAURO GALETTI, VARUN R. GOSWAMI, MATT W. HAYWARD, SIMON HEDGES, MICHAEL HOFFMANN, LUKE T. B. HUNTER, GRAHAM I. H. KERLEY, MIKE LETNIC, TAAL LEVI, FIONA MAISELS, JOHN C. MORRISON, MICHAEL PAUL NELSON, THOMAS M. NEWSOME, LUKE PAINTER, ROBERT M. PRINGLE, CHRISTOPHER J. SANDOM, JOHN TERBORGH, ADRIAN TREVES, BLAIRE VAN VALKENBURGH, JOHN A. VUCETICH, AARON J. WIRSING, ARIAN D. WALLACH, CHRISTOPHER WOLF, ROSIE WOODROFFE, HILLARY YOUNG, AND LI ZHANG rom the late Pleistocene to the megafauna are imperiled (species in reduced resource availability. Although Downloaded from F Holocene and now the so-called tables S1 and S2) and to stimulate some species show resilience by adapt- Anthropocene, humans have been broad interest in developing specific ing to new scenarios under certain driving an ongoing series of species recommendations and concerted conditions (Chapron et al. 2014), declines and extinctions (Dirzo et al. action to conserve them. livestock production, human popula- 2014). Large-bodied mammals are Megafauna provide a range of dis- tion growth, and cumulative land-use http://bioscience.oxfordjournals.org/ typically at a higher risk of extinction tinct ecosystem services through top- impacts can trigger new conflicts or than smaller ones (Cardillo et al. 2005). down biotic and knock-on abiotic exacerbate existing ones, leading to However, in some circumstances, ter- processes (Estes et al. 2011). Many additional declines. According to the restrial megafauna populations have megafauna function as keystone spe- Food and Agriculture Organization, been able to recover some of their lost cies and ecological engineers, gen- as of 2014, there were an estimated 3.9 numbers because of strong conserva- erating strong cascading effects in billion ruminant livestock on Earth tion and political commitment, as well the ecosystems in which they occur. compared with approximately 8.5 mil- as human cultural changes (Chapron These species also provide impor- lion individuals of 51 of the 74 spe- et al. 2014). Indeed, many would be tant economic and social services. cies of wild megaherbivores for which in considerably worse predicaments For example, ecotourism is the fast- population estimates are available at Oxford Journals on July 27, 2016 in the absence of conservation action est growing subsector of tourism in within their native ranges (table S2), a (Hoffmann et al. 2015). Nevertheless, developing countries (UNEP 2013), magnitude difference of approximately most mammalian megafauna face dra- and megafauna are a major draw for 400 times. matic range contractions and popu- these tourists. Besides contributing The current depletion of mega- lation declines. In fact, 59% of the considerable revenue to conservation, fauna is also due to overhunting and world’s largest carnivores (more than wildlife-based tourism can contribute persecution: shooting, snaring, and or equal to 15 kilograms, n = 27) and significantly to education, economies, poisoning by humans ranging from 60% of the world’s largest herbivores job creation, and human livelihoods. individuals to governments, as well as (more than or equal to 100 kilograms, Many of the surviving mammalian by organized criminals and terrorists n = 74) are classified as threatened with megafauna remain beset by long- (Darimont et al. 2015). Megafauna extinction on the International Union standing and generally escalating are killed for meat and body parts for the Conservation of Nature (IUCN) threats of habitat loss, persecution, for traditional medicine and orna- Red List (supplemental tables S1 and and exploitation (Ripple et al. 2014, ments or because of actual or per- S2). This situation is particularly dire 2015). Large mammals are extremely ceived threats to humans, their crops, in sub-Saharan Africa and Southeast vulnerable to these threats because or livestock. Meat and body parts are Asia, home to the greatest diversity of of their large area requirements, low sold locally, sold to urban markets, extant megafauna (figure 1). Species at densities (particularly for carnivores), or traded regionally and internation- risk of extinction include some of the and relatively “slow” life-history traits ally. Striking instances include the world’s most iconic animals—such as (Wallach et al. 2015). Various anthro- slaughter of thousands of megafauna, gorillas, rhinos, and big cats (figure 2 pogenic forces such as deforestation, such as African elephants (Loxodonta top row)—and, unfortunately, they are agricultural expansion, increasing live- africana) for their ivory, rhinoceroses vanishing just as science is discov- stock numbers, and other forms of for their horns, and tigers (Panthera ering their essential ecological roles human encroachment have severely tigris) for their body parts. In addi- (Estes et al. 2011). Here, our objectives degraded critical habitat for mega- tion, many lesser-known megafauna are to raise awareness of how these fauna by increased fragmentation or species (figure 2, bottom row) are now http://bioscience.oxfordjournals.org XXXX XXXX / Vol. XX No. X r BioScience 1 Viewpoint Downloaded from http://bioscience.oxfordjournals.org/ at Oxford Journals on July 27, 2016 Figure 1. A richness map of (a) the number of megafaunal species, (b) the number of declining megafauna species, and (c) the number of threatened megafaunal species in their native ranges. Megafauna are defined as terrestrial large carnivores (more than 15 kilograms) and large herbivores (more than 100 kilograms). Threatened includes all species categorized as Vulnerable, Endangered, or Critically Endangered on the IUCN Red List (see supplemental tables). 2 BioScience r XXXX XXXX / Vol. XX No. X http://bioscience.oxfordjournals.org Viewpoint Downloaded from http://bioscience.oxfordjournals.org/ Figure 2. Photographic examples of threatened megafauna. Top row left to right: photos of well-known species, including the Western gorilla (Gorilla gorilla) (CR), black rhino (Diceros bicornis) (CR), and Bengal tiger, (Panthera tigris tigris) at Oxford Journals on July 27, 2016 (EN). Bottom row left to right: photos of lesser-known species, including the African wild ass (Equus africanus) (CR), Visayan warty pig (Sus cebifrons) (CR), and banteng (Bos javanicus) (EN). Photo credits: Julio Yeste, Four Oaks, Dave M. Hunt, Mikhail Blajenov, KMW Photography, and Kajornyot. imperiled (tables S1 and S2). Most (IUCN 2015). The Sumatran rhino declined markedly in many protected of the world’s megaherbivores remain (Dicerorhinus sumatrensis) is already areas (IUCN 2015). poorly studied, and this knowledge extinct in the wild in Malaysia and is Although many of the general gap makes conserving them even more very close to extinction in Indonesia, causes and mechanisms of declines difficult (Ripple et al. 2015). with the population collapsing during are well identified and recognized, this Under a business-as-usual scenario, the last 30 years from over 800 to fewer understanding has not translated into conservation scientists will soon be than 100 (table S2). The Javan rhino adequate conservation action. Some busy writing obituaries for species and (Rhinoceros sondaicus) is down to a of the existing mammal-prioritiza- subspecies of megafauna as they vanish single population of approximately tion schemes could be incorporated from the planet. In fact, this process is 58 in a single reserve (table S2). The into a comprehensive global strategy already underway: eulogies have been Critically Endangered Bactrian camel for conserving the largest mammals written for Africa’s western black rhi- (Camelus ferus) and African wild ass (Rondinini et al. 2011). Increasing pri- noceros (Diceros bicornis longipes) and (Equus africanus) are not far behind. oritization and political will to conserve the Vietnamese subspecies of the Javan Even in protected areas, megafauna megafauna—and actions to restore rhinoceros (Rhinoceros sondaicus are increasingly under assault. For or reintroduce them in areas where annamiticus, IUCN 2015). Epitaphs example, in West and Central Africa, they have declined or been extirpated will probably soon be needed for the several large carnivores (including (such as plans to reintroduce scimitar- kouprey (Bos sauveli), last seen in lions, Panthera leo; African wild dogs, horned oryx into Chad and to rehabili- 1988; and the northern white rhinoc- Lycaon pictus; and cheetahs, Acinonyx tate the entire Gorongosa ecosystem in eros (Ceratotherium simum cottoni), jubatus) have experienced recent Mozambique)—are urgently needed. which now numbers three individuals severe range contractions and have We suggest that the problem has two http://bioscience.oxfordjournals.org XXXX XXXX / Vol. XX No. X r BioScience 3 Viewpoint Box 1. A declaration to save the world’s terrestrial megafauna. We conservation scientists 1. Acknowledge that most of the terrestrial megafauna species are threatened with extinction and have declining populations. Some megafauna species that are not globally threatened nonetheless face local extinctions or have Critically Endangered subspecies. 2. Appreciate that “business as usual” will result