Bushmeat hunting and extinction risk to the world's mammals

Abstract

Terrestrial mammals are experiencing a massive collapse in their population sizes and geographical ranges around the world, but many of the drivers, patterns and consequences of this decline remain poorly understood. Here we provide an analysis showing that bushmeat hunting for mostly food and medicinal products is driving a global crisis whereby 301 terrestrial mammal species are threatened with extinction. Nearly all of these threatened species occur in developing countries where major coexisting threats include deforestation, agricultural expansion, human encroachment and competition with livestock. The unrelenting decline of mammals suggests many vital ecological and socio-economic services that these species provide will be lost, potentially changing ecosystems irrevocably. We discuss options and current obstacles to achieving effective conservation, alongside consequences of failure to stem such anthropogenic mammalian extirpation. We propose a multi-pronged conservation strategy to help save threatened mammals from immediate extinction and avoid a collapse of food security for hundreds of millions of people.

Keywords: bushmeat; extinction; hunting; mammals; wild meat.

Figure 1.

The percentage of species threatened by hunting for human consumption and other threatened species in each mammalian order. The values on the x-axis refer to the percentage of species out of all mammal species in each order. The category ‘Other threatened species’ consists of the other threatened mammal species where hunting for consumption is not a primary or major threat. Horizontal bars are sorted from highest to lowest total percentage of threatened species in each order. Numbers on the y-axis after the order names are the number of species threatened by hunting followed by the total number of species in the order. Elephants are threatened by hunting but not listed here because they are predominately killed for their ornamental ivory and not for the consumption of meat or medicine (see [14]). The order Notoryctemorphia (marsupial moles) was omitted as it contains only data-deficient species.

Figure 2.

Number (a) and percentage (b) of mammal species threatened by hunting grouped by body mass in kilograms. The values correspond to species threatened by hunting out of all terrestrial mammals in each body mass group, respectively. Body mass data come from [–25].

Figure 3.

Species richness maps for (a) all terrestrial mammals and (b) mammals threatened by hunting.

Figure 4.

Research effort for mammal species threatened by hunting. The variable shown is the median number of articles published between 1965 and 2016 for all of the species threatened by hunting found in each hexagon (see text).

Figure 5.

Mammal species threatened by hunting span a range of taxonomic and trophic groups, and perform a wide range of functional roles, ranging from seed dispersal to pest control to ecosystem engineering and regulation. Endangerment classification for each species noted on the image. Status categories are vulnerable (VU), endangered (EN) and critically endangered (CR). See the electronic supplementary material for photo credits. See electronic supplementary material, table S1 for population trends and endangerment category definition and trends. (a) Predators, left to right: clouded leopard (Neofelis nebulosa), tiger (Panthera tigris), marbled cat (Pardofelis marmorata). (b) Herbivores, left to right: Bactrian camel (Camelus ferus), takin (Camelus ferus), Nilgiri tahr (Nilgiritragus hylocrius). (c) Insectivores, left to right: long-beaked echidna (Zaglossus bruijnii), giant ground pangolin (Smutsia gigantea), aye aye (Daubentonia madagascariensis). (d) Frugivores & granivores, left to right: Madagascan fruit bat (Pterofus rufus), collared brown lemur (Eulemur collaris) and Sulawesi giant squirrel (Rubrisciurus rubriventer).