Once oil palm has replaced the immense variety of hundreds of species of trees, vines, shrubs, mosses, and other plants found on every acre of lowland rainforest, most animals can no longer live there. An oil palm plantation is, in effect, a "biological desert." As an industrial plantation crop, oil palm is grown as a monoculture. Most of the other plants found are low-growing ground cover. Without the rainforest's plenteous variety of fruits, nuts, leaves, roots, nectar, bark, shoots, and other plant materials to eat, most animals cannot survive. And, without plenty of plant-eating prey animals such as deer to hunt, carnivores such as tigers cannot survive either. The plantations provide habitat for only 20 percent or less of the previously resident mammals, reptiles, and birds Endangered Rainforest MammalsThe loss of rainforest habitat will swiftly and inevitably lead to the complete disappearance of many unique mammal species. This section presents five animals as examples of the devastation to come: the Sumatran tiger, Sumatran and Bornean orangutans, Asian elephant, and Sumatran rhinoceros. Each of those species is endangered according to the IUCN Red List Moreover, the three eponymous Sumatran species are considered critically endangered - a status largely due to loss of habitat (see figure 5 here below).
Each of the five species discussed here requires connected areas of rainforest to survive. They once flourished in the areas where forests have since been cleared for oil palm - especially the islands of Borneo and Sumatra. On those two islands, 60 percent of rainforest was lost just between 1985 and 1997. The Sumatran orangutan, Bornean orangutan, and Sumatran tiger exist only on the islands of Sumatra or Borneo and nowhere else in the world. The Sumatran rhinoceros has remnant populations on both Sumatra and Borneo, with a small population in Peninsular Malaysia and a few other scattered remnants elsewhere. A significant number of the remaining Asian elephants occur in Sumatra and Borneo ; the species is also found in continental Asian countries.
Sumatran tiger . The Sumatran tiger (Panthera tigris sumatrae) is one of only five remaining tiger subspecies, reduced from eight by recent extinctions. Sumatran tigers live in rainforest. Adults of both sexes are mainly solitary, except for females with cubs. An adult tiger has its own wide-ranging home territory, about 20 to 30 square miles for a female tiger ; a male tiger's home range may be even larger because his overlaps the ranges of several females.
Tigers feed on prey animals that weigh about 100 to 450 pounds, such as deer and wild pigs, which also live in the rainforest. A single adult tiger eats 40 pounds of meat at a sitting and must kill about 75 large prey a year to survive. To support a tiger population, an area of rainforest habitat must be big enough to support a sufficient population of large prey animals. Population density of Sumatran tigers thus depends on availability of prey. Considering their expansive home ranges, 2,000 to 3,000 square miles of rainforest might be needed for a subpopulation of about 100 tigers. A number of subpopulations, each large enough to be genetically healthy, would be needed to rescue the species from the threat of extinction.
Elephant Killing in Sumatra
In November 2004, six wild elephants were poisoned to death in Sumatra after they encroached on an oil palm plantation. The killing of elephants, as well as of endangered tigers, is not unusual on the island, where illegal logging and farming have shrunk those and other animals' natural habitat and increased their contact with humans . The elephants were found dead in Kepenuhan Tengah, a village in Rokan Hulu, Riau. Five were simply poisoned; the sixth was burned after being poisoned. The corpses were found south of the Libo Forest Block, where the concessions of PT Manday Abadi, PT Rokan Permai Timber, and PT Rokan Timber Corporation operate. Workers on an oil palm plantation admitted sickening the elephants with rat poison. According to the Associated Press story in the Jakarta Post, one worker said, "The wild elephants have become a big problem for us and we had no other choice than to poison them so we could secure the plantation." The animals are believed to be from the already critically small elephant group in Riau, the Rambah Hilir elephant group, whose population of 30 to 35 elephants in 2003 is significantly reduced from its level of 100 to 200 in 1995.
Each of the five species discussed here requires connected areas of rainforest to survive. They once flourished in the areas where forests have since been cleared for oil palm - especially the islands of Borneo and Sumatra. On those two islands, 60 percent of rainforest was lost just between 1985 and 1997. The Sumatran orangutan, Bornean orangutan, and Sumatran tiger exist only on the islands of Sumatra or Borneo and nowhere else in the world. The Sumatran rhinoceros has remnant populations on both Sumatra and Borneo, with a small population in Peninsular Malaysia and a few other scattered remnants elsewhere. A significant number of the remaining Asian elephants occur in Sumatra and Borneo ; the species is also found in continental Asian countries.
Sumatran tiger . The Sumatran tiger (Panthera tigris sumatrae) is one of only five remaining tiger subspecies, reduced from eight by recent extinctions. Sumatran tigers live in rainforest. Adults of both sexes are mainly solitary, except for females with cubs. An adult tiger has its own wide-ranging home territory, about 20 to 30 square miles for a female tiger ; a male tiger's home range may be even larger because his overlaps the ranges of several females.
Tigers feed on prey animals that weigh about 100 to 450 pounds, such as deer and wild pigs, which also live in the rainforest. A single adult tiger eats 40 pounds of meat at a sitting and must kill about 75 large prey a year to survive. To support a tiger population, an area of rainforest habitat must be big enough to support a sufficient population of large prey animals. Population density of Sumatran tigers thus depends on availability of prey. Considering their expansive home ranges, 2,000 to 3,000 square miles of rainforest might be needed for a subpopulation of about 100 tigers. A number of subpopulations, each large enough to be genetically healthy, would be needed to rescue the species from the threat of extinction.
Elephant Killing in Sumatra
In November 2004, six wild elephants were poisoned to death in Sumatra after they encroached on an oil palm plantation. The killing of elephants, as well as of endangered tigers, is not unusual on the island, where illegal logging and farming have shrunk those and other animals' natural habitat and increased their contact with humans . The elephants were found dead in Kepenuhan Tengah, a village in Rokan Hulu, Riau. Five were simply poisoned; the sixth was burned after being poisoned. The corpses were found south of the Libo Forest Block, where the concessions of PT Manday Abadi, PT Rokan Permai Timber, and PT Rokan Timber Corporation operate. Workers on an oil palm plantation admitted sickening the elephants with rat poison. According to the Associated Press story in the Jakarta Post, one worker said, "The wild elephants have become a big problem for us and we had no other choice than to poison them so we could secure the plantation." The animals are believed to be from the already critically small elephant group in Riau, the Rambah Hilir elephant group, whose population of 30 to 35 elephants in 2003 is significantly reduced from its level of 100 to 200 in 1995.
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