ReviewECOLOGY

Collapse of the world’s largest herbivores

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Science Advances  01 May 2015:
Vol. 1, no. 4, e1400103
DOI: 10.1126/sciadv.1400103
  • Fig. 1 Large herbivore total species richness (A) and threatened (B) at the ecoregion level.

    Ecoregion lists for each species were obtained using the IUCN Red List species range maps and (3) and are based on the ecoregions where each species is native and currently present.

  • Fig. 2 Proportion of large herbivore species listed as threatened by IUCN.

    The total number of herbivore species in each family is shown after each family name. Individual threatened species by family include Elephantidae: African elephant (VU), Asian elephant (EN); Hippopotamidae: hippopotamus (VU), pygmy hippopotamus (EN); Hominidae: eastern gorilla (EN), western gorilla (EN); Tapiridae: Malayan tapir (VU), Baird’s tapir (EN), lowland tapir (VU), mountain tapir (EN); Suidae: Philippine warty pig (VU), Oliver’s warty pig (EN), Visayan warty pig (CR), Palawan bearded pig (VU), bearded pig (VU); Rhinocerotidae: Indian rhinoceros (CR), Javan rhinoceros (CR), Sumatran rhinoceros (CR), black rhinoceros (CR); Equidae: Grevy’s zebra (EN), mountain zebra (VU), African wild ass (CR), Przewalski’s horse (EN), Asiatic wild ass (CR); Cervidae: sambar (VU), barasingha (VU), Père David’s deer (EW), white-lipped deer (VU); Camelidae: bactrian camel (CR); Bovidae: Indian water buffalo (EN), gaur (VU), kouprey (CR), European bison (VU), wild yak (VU), banteng (EN), takin (VU), lowland anoa (EN), tamaraw (CR), mountain nyala (EN), scimitar-horned oryx (EW), mountain anoa (EN), Sumatran serow (VU), walia ibex (EN). Scientific names in table S1.

  • Fig. 3 Range contractions over time for three iconic African herbivores.

    African elephant (ca. 1600 versus 2008), common hippopotamus (ca. 1959 versus 2008), and black rhinoceros (ca. 1700 versus 1987). The historical ranges are in blue, whereas the most recent ranges are represented by darker-colored polygons. For security purposes, the most recent black rhinoceros range polygons (1987) have been moved by random directions and distances. The black rhinoceros range has continued to shrink since 1987 across most of Africa, but has expanded locally in Zambia, South Africa, and Namibia through recent reintroductions, and the most current range polygons are not shown because of the recent poaching pressure on the rhinoceros. Photo Credits: Elephant and hippopotamus (K. Everatt), rhinoceros (G. Kerley).

  • Fig. 4 Proximate threats faced by large herbivores globally.

    Threats faced by each species were categorized using information in the IUCN Red List species fact sheets. The total adds up to more than 100% because each large herbivore species may have more than one existing threat.

  • Fig. 5 Conceptual diagrams showing the effects of elephants, hippopotamus, and rhinoceros on ecosystems.

    (A) African elephants (L. africana) convert woodland to shrubland (53), which indirectly improves the browse availability for impala (A. melampus) (53) and black rhinoceros (D. bicornis minor) (54). By damaging trees, African elephants facilitate increased structural habitat complexity benefiting lizard communities (100). Predation by large predators (for example, lions) on small ungulates is facilitated when African elephants open impenetrable thickets (48). African elephants are also great dispersers of seeds over long distances (13). (B) Hippopotamus (H. amphibius) maintain pathways in swamps, leading to new channel systems (101). Areas grazed by hippopotamus are often more nutritious, which benefits kob (K. kob) (55). Mutualism and semiparasitism between hippopotamus and birds have also been shown, via the latter eating insects on hippopotamus (73). (C) White rhinoceros (C. simum) maintain short grass patches in mesic areas, which increases browse for other grazers (impalas, wildebeests, C. taurinus, and zebra, Equus burchelli) and changes fire regimes (71).

  • Fig. 6 Photos of selected threatened large herbivore species.

    Endangerment status and photo credits include the following: lowland tapir (Tapirus terrestris), vulnerable, T. Newsome; mountain nyala (T. buxtoni), endangered, H. Hrabar; European bison (B. bonasus), vulnerable, G. Kerley; eastern gorilla (Gorilla beringei), endangered, P. Stoel; mountain zebra (Equus zebra), vulnerable, H. Hrabar.

  • Fig. 7 Global change in the collective mass for wild mammals, humans, cattle, and all livestock for the years 1900–2050.

    Values for 1900 and 2000 are from (102). Human, cattle, and livestock biomass forecasts are based on projected annual growth in human population, beef production, and meat production, respectively (88, 102).

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/1/4/e1400103/DC1

    Fig. S1. Regional patterns of endangerment of large herbivores.

    Fig. S2. Number of published scientific articles by species.

    Fig. S3. Comparison of Pleistocene extinctions by body mass with current threatened species by body mass.

    Fig. S4. Global distribution of the four main threats faced by large herbivores.

    Fig. S5. Human population trends and projections by region (top) and ruminant livestock trends by region (bottom).

    Fig. S6. Current range maps (sorted by family) for the 72 large herbivores not classified as extinct in the wild (EW).

    Table S1. Data on the 74 large terrestrial herbivores above 100 kg.

    Table S2. The number of large herbivores (threatened, total, and facing each of the four main threats) found in each ecoregion.

    Table S3. The number of large herbivores (threatened and total) found in each ecoregion.

    Table S4. The threatened large herbivores found in each of the ecoregions with at least five threatened large herbivores.

    Table S5. Summary of research effort for the period 1965 to June 2014.

    References (103107)

  • Supplementary Materials

    This PDF file includes:

    • Fig. S1. Regional patterns of endangerment of large herbivores.
    • Fig. S2. Number of published scientific articles by species.
    • Fig. S3. Comparison of Pleistocene extinctions by body mass with current threatened species by body mass.
    • Fig. S4. Global distribution of the four main threats faced by large herbivores.
    • Fig. S5. Human population trends and projections by region (top) and ruminant livestock trends by region (bottom).
    • Fig. S6. Current range maps (sorted by family) for the 72 large herbivores not classified as extinct in the wild (EW).
    • Table S1. Data on the 74 large terrestrial herbivores above 100 kg.
    • Table S2. The number of large herbivores (threatened, total, and facing each of the four main threats) found in each coregion.
    • Table S3. The number of large herbivores (threatened and total) found in each ecoregion.
    • Table S4. The threatened large herbivores found in each of the ecoregions with at least five threatened large herbivores.
    • Table S5. Summary of research effort for the period 1965 to June 2014.
    • References (103–107)

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