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Western Lowland Gorilla (Gorilla gorilla gorilla). (Photo by R. Butler)
MAMMALS of the FOREST FLOOR
As a result of the lack of abundant ground growth, the tropical rainforest supports few large-bodied herbivores and consequently an even smaller population of large predators. The majority of ground-dwelling animals are small to medium-sized creatures that feed on fallen fruits and seeds, saplings, and small prey.
HERBIVORES
Because much of the vegetation is above the reach of forest animals, tropical rainforests support only a small biomass of large herbivores, especially in comparison with surrounding savanna areas. Much of their sustenance comes from the consumption of fallen fruits, seeds, and flowers.
FALLEN FRUIT AND SEED COLLECTORS
Whole niches have opened for species that feed exclusively on fallen matter. Convergent evolution has resulted in species with similar adaptations and appearance on each forested continent, even though none belong to the same family. This niche is filled in Asia by the mouse deer; in Africa by the duikers; and in South and Central America by the agouti. All three animal groups are similar in structure—about the size of a rabbit with thin legs and sharp claws on their hooves—and similar behavior—all three are nervous animals due to their highly sought and appreciated meat.
There are at least six species of duikers, a type of small antelope, which feed only on fallen fruit and seeds. The African rainforest is able to support this diversity in any one location because each species has adapted to feed on a unique type of seed. For example, one species is able to eat huge fruits by having a flexible jaw. Another species has special teeth which enable it to crack some of the hardest seeds in the rainforest.
Agoutis, acouchis, and pacas, all cat-sized, primarily nocturnal, rodents of the New World, are examples of the incredible rodent radiation in the New World. New World rodents are important seed dispersers in tropical rainforests, like the squirrels of temperate regions, in that they collect seeds and bury them in scattered stashes over a relatively wide range. A good portion of the seed caches go unclaimed and the seeds germinate, now safely distanced from the parent tree. Agoutis and pacas are active in the same forests, but avoid direct competition by feeding at different times: agoutis tend to be more diurnal (day-active), while Pacas tend to be nocturnal.
LARGE HERBIVORES
Mammal life in the tropical rainforest is as abundant and diverse as the other life forms there. However, small mammals are the rule and larger mammals are far less common than in temperate forests and the African savannas. The scarcity of large mammals is in part due to the lack of leaves at ground level on which to feed. Only a few large mammal species exist in tropical rainforests: the okapi, the elephant, the pygmy hippo, the bongo, and the gorilla of Africa; the tapir, the rhinoceros, the forest deer, and the elephant of Asia; and the tapir of South America.
The bizarre Okapi is a primitive giraffe, about the size of a horse, found in a small region of rainforest in Zaire bordered by the Ituri, Uele, and Zaire rivers. It has striped legs like a zebra to help it blend into the shadows of the forest and a long neck to reach leaves above the floor. The okapi is solitary or lives in pairs and feeds on foliage that is shunned by other forest creatures. The okapi was only discovered by Western science in 1899 and less than 10,000 individuals exist today. During the recent civil strife in the Democratic Republic of Congo (Zaire), the Okapi Faunal Reserve suffered much encroachment from fleeing refugees and militias. It is unknown at this time how the okapi population fared.
The gorilla is the world's largest primate, weighing up to 660 pounds (300 kg), having an armspan exceeding 6.6 feet (2 m), and standing six feet (1.8 m) on all fours and even taller when erect (females usually weigh less than 120 kg-265 pounds). Gorillas are represented by two subspecies: the western gorilla of lowland rainforests in Gabon, Cameroon, Nigeria, and Congo; and the eastern or mountain gorilla of the montane cloud forests in Uganda, Rwanda, and Congo (Zaire). Gorillas live in family groups consisting of one dominant silverback male, one to three sub-adult males, females, and juveniles. Gorillas build nests each night; males usually build theirs on the ground or low branches, while females build their quarters higher up in trees. Silverback males have virtually complete control over the group and dictate when to commence nest-building, when to forage, and how to accept intruders. Gorillas, despite a reputation for being brutal, are actually gentle, investigative creatures that feed on leaves, stems, and bamboo shoots [news and information on gorillas | photos].
African elephants are the largest land mammals of the world and are usually associated with the open savannas and plains of Africa. However, some African elephants (now considered a separate subspecies of elephant) do enter the Ituri rainforest of Zaire where they play an essential, although poorly understood, role as "architects of the rainforest." Elephants create clearings in the forest where they gather at mineral deposits and preferred drinking spots. After hundreds and even thousands of years of elephant trampling and digging, some of these clearings may reach several hundred yards across. The elephants keep these clearings open by trampling young colonizing plants and feeding on new leaves. These clearings attract other species which drink at the water hole and hunt prey exposed in the open area. Elephants, by feeding on young leaves in the forest, also allow more light to penetrate the canopy and reach the forest floor. Elephants not only clear areas, but also contribute to tree dispersal, in that several species of seed will only germinate after passing through an elephant's gut. [news and information on elephants | photos]
Asia
Like African elephants, Asian elephants play a similar role in the tropical rainforests of India and Southeast Asia. They have even been introduced into the world's third largest island, Borneo, when they were given as a gift to the sultan in the early 19th century.
Asia, like Africa, also possesses rhinoceroses, but those of Asia are more associated with the rainforest and are much smaller. Both the Sumatran and Java rhino are on the brink of extinction from habitat loss and hunting for their horn, which is ground up into a fine powder and used for medicinal purposes despite its composition: 100 percent keratin—the same structural material of fingernails. It is estimated that there are only 413-563 Sumatran rhinos left [news and information on rhinos | photos].
The Malay tapir is the largest of four species of tapir found worldwide. Related to horses and rhinos (Perissodactyla Order), the tapir resembles a giant pig with a sawed-off elephant trunk, and has a short, thick body which may reach eight feet (2.4 m) in length. The tapir likes to be near water and is an excellent swimmer. It feeds on grass, leaves, and fallen fruits. Like the tapir of the New World, the Malay tapir lives alone or in pairs.
South America
There are three species of tapir in the Americas: two mountain tapirs of the Andes in Columbia and Ecuador, and the extremely rare Baird's Tapir ranging from Mexico to Ecuador. Tapirs are most closely related to horses and rhinos, despite their appearance, and have a mobile proboscis. Tapirs have recently become the focus of a new IUCN campaign because of their rapidly declining numbers.
Hunting across Southeast Asia weakens forests' survival, An interview with Richard Corlett
(11/08/2009) A large flying fox eats a fruit ingesting its seeds. Flying over the tropical forests it eventually deposits the seeds at the base of another tree far from the first. One of these seeds takes root, sprouts, and in thirty years time a new tree waits for another flying fox to spread its speed. In the Southeast Asian tropics an astounding 80 percent of seeds are spread not by wind, but by animals: birds, bats, rodents, even elephants. But in a region where animals of all shapes and sizes are being wiped out by uncontrolled hunting and poaching—what will the forests of the future look like? This is the question that has long occupied Richard Corlett, professor of biological science at the National University of Singapore.
"Money is not a problem," palm oil CEO tells conservationists during speech defending the industry
(10/26/2009) Earlier this month at a colloquium to implement wildlife corridors for orangutans in the Malaysian state of Sabah, Dr. Yusof Basiron, the CEO of Malaysian Palm Oil Council (MPOC), told conservationists and primate experts that the palm oil industry was ready to fund reforestation efforts in the corridors. "We can raise the money to replant [the corridors] and keep contributing as a subsidy in the replanting process of this corridor for connecting forests," Basiron said in response to a question on how the palm oil industry will contribute. "Money is not a problem. The commitment is already there, the pressure is already very strong for this to be done, so it's just trying to get the thing into motion."
New reserve created in Cambodia with REDD in mind
(10/26/2009) Cambodia's Royal Government's Council of Ministers has declared the creation of the Seima Protection Forest, a 1,100 square miles (2,849 square kilometers) park home to tigers, elephants, and endangered primates. The park's creation was developed in part by the Wildlife Conservation Society's (WCS) "Carbon for Conservation" program, which intends to protect high-biodiversity ecosystems while raising funds through carbon sequestration schemes such as Reducing Emission from Deforestation and Degradation (REDD).
Perfect shot of the rare Iberian wolf wins nature photo contest
(10/22/2009) It's hard to believe the shot is real: it's that good. But a photo of a rare Iberian wolf—a subspecies of the gray wolf—jumping a fence has won the 45th Veolia Environment Wildlife Photo of the Year award. The photographer, Jose Luis Rodriguez, has said that he hopes the haunting image will inspire the people of Spain to be proud to have this endangered animal still roaming their countryside.
Emotional call for palm oil industry to address environmental problems
(10/21/2009) During what was at times an emotional speech, Sabah's Minister of Tourism, Culture, and Environment, Datuk Masidi Manjun, called on the palm oil industry to stop polluting rivers and work with NGOs to save orangutans and other wildlife. He delivered the speech on the first day of an Orangutan Conservation Colloquium held in early October in the Malaysian state of Sabah on the island of Borneo.
