Geoscience Reference
In-Depth Information
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Forest Elephants and Plant Survival
Controversy remains as to whether the forest elephant is a subspecies or an entirely different spe-
cies from the African elephant of the savanna. Recent DNA evidence suggests that the elephants
are genetically different enough to warrant species designation, yet the debate continues.
Although once abundant, populations have severely declined. Only very small, probably unsus-
tainable groups exist in West Africa, with only 7 percent of its former range intact. Larger popula-
tions remain in the Congo Basin of Central Africa.
Forest elephants are opportunistic feeders. Some favor particular fruits and journey distances
to find them. Often, many elephant trails lead to the same majestic makore tree (Tieghemella heck-
elii), where elephants gather until fruit is no longer available. The makore tree produces large,
hard-shelled fruit with thick pits that may depend on elephants for germination. In one area of
Ghana, where forest elephants were eliminated, makore seedlings are no longer found. Another
fruit favored by elephants is that of the strychnine plant, a liana that grows high in the canopy. Its
fruit is a green-yellow sphere about the size of a pumpkin and so hard that few animals can con-
sume it. Elephants are able to crack the shell and expose the seeds. The elephant consumes the
seeds, which have an intoxicating effect on them. Defecated seeds germinate in a fertilizer of ele-
phant dung.
Plants dependent on elephants for dispersal and germination have nutrient-rich fruits with
strong odors and hard shells that attract elephants. Elephants help with seed dispersal and germi-
nation in up to 30 percent of West African trees. The Guinea plum tree, wild mango, and the panda
plant, among others, have large pitted fruits dispersed by elephants that germinate in elephant
dung. With decreasing numbers of elephants, the loss of many forest trees seems inevitable.
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hunters of rodents, tree hyraxes, birds, and duikers and rest in the trees during the
day. The leopard is the largest carnivore in the tropical rainforests of Africa. Leop-
ards are solitary, nocturnal predators. Their fur can range from straw-colored with
black spots to almost completely black. The spotted patterns act as camouflage in
the sun-dappled forest. Leopards stalk their prey and then quickly rush to catch it.
They can run up to 60 mph (96 kph) in short bursts. When the hunt is successful,
the leopard will drag its prey into the bushes or up onto a tree branch to keep it
away from other predators and scavengers.
Birds
A variety of birds live within the African rainforest, yet fewer birds inhabit a com-
parable area of the African rainforest than in the Neotropics, Asia, or New Guinea.
The dominant families include cuckoos, kingfishers, hornbills, bulbuls, shrikes,
Old World Warblers, flycatchers, sunbirds, and weavers. None of these birds occur
in the Neotropical rainforest, but most are represented in the Asian-Pacific forests.
The birds of tropical Africa that eat fruits, nuts, and seeds tend to be large and
brightly colored. Large size lets the bird consume larger fruits and more fruits in
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