The composition of the wildlife of Madagascar reflects the fact that the
island has been isolated for about 88 million years. The prehistoric breakup
of the supercontinent Gondwana separated the Madagascar-Antarctica-India landmass
from the Africa-South America landmass around 135 million years ago. Madagascar
later split from India about 88 million years ago, allowing plants and animals
on the island to evolve in relative isolation. As a result of the island's
long isolation from neighboring continents, Madagascar is home to an
abundance of plants and animals found nowhere else on Earth. Approximately 90
percent of all plant and animal species found in Madagascar are endemic,
including the lemurs, the carnivorous fossa and many birds. This distinctive
ecology has led some ecologists to refer to Madagascar as the "eighth continent",
and the island has been classified by Conservation International as a
biodiversity hotspot. Fauna
Madagascar's isolation from other land masses throughout the Cenozoic Era has
led to the evolution of a large proportion of endemic animal species and
the absence of many taxa found on neighboring continents. Some of
Madagascar's animals appear to represent lineages that have been present since
the breakup of Gondwana, while many others, including all of the nonflying
native mammals, are descendants of ancestors that survived rare rafting or
swimming voyages from Africa. As of 2012 it has over 200 extant mammal species,
including over 100 species of lemurs, about 300 species of birds, more than
260 species of reptiles, and at least 266 species of amphibians. The island
also has a rich invertebrate fauna including earthworms, insects, spiders
and nonmarine molluscs. Lemurs have been characterized as
"Madagascar's flagship mammal species" by Conservation International. In the
absence of monkeys and other competitors, these primates have adapted
to a wide range of habitats and diversified into numerous species. As of
2012, there were officially 103 species and subspecies of lemur, 39 of which
were described by zoologists between 2000 and 2008. They are almost all
classified as rare, vulnerable, or endangered. At least 17 species of lemur
have become extinct since man arrived on Madagascar, all of which were larger
than the surviving lemur species. A number of other mammals, including the
cat-like fossa, are endemic to Madagascar. Over 300 species of birds
have been recorded on the island, of which over 60 percent are endemic. The
few families and genera of reptile that have reached Madagascar have diversified
into more than 260 species, with over 90 percent of these being endemic. The
island is home to two-thirds of the world's chameleon species, including the
smallest known, and researchers have proposed that Madagascar may be the
origin of all chameleons. Endemic fish of Madagascar include two families, 15
genera and over 100 species, primarily inhabiting the island's freshwater lakes
and rivers. Although invertebrates remain poorly studied on Madagascar,
researchers have found high rates of endemism among the known species. All
651 species of terrestrial snail are endemic, as are a majority of the
island's butterflies, scarab beetles, lacewings, spiders and dragonflies.
Flora More than 80 percent of Madagascar's
14,883 plant species are found nowhere else in the world, including five plant
families. There are several endemic families including the Asteropeiaceae,
Sarcolaenaceae and Sphaerosepalaceae. The humid eastern part of the island was
formerly covered in rainforest with many palms, ferns and bamboo, although much
of this forest has been reduced by human activity. The west has areas of dry
deciduous forest with many lianas and with tamarind and baobabs among the
dominant trees. Subhumid forest once covered much of the central plateau but
grassland is now the dominant vegetation type there. The family Didiereaceae,
composed of four genera and 11 species, is limited to the spiny forests of
southwestern Madagascar. Four-fifths of the world's Pachypodium
species are endemic to the island. Three-fourths of Madagascar's 860 orchid
species are found here alone, as are six of the world's eight baobab species. The
island is home to around 170 palm species, three times as many as on all
of mainland Africa; 165 of them are endemic. Many native plant species are
used as herbal remedies for a variety of afflictions. The drugs vinblastine and
vincristine, used to treat Hodgkin's disease, leukemia and other cancers,
were derived from the Madagascar periwinkle. The traveler's palm, known
locally as ravinala and endemic to the eastern rain forests, is highly iconic
of Madagascar and is featured in the national emblem as well as the Air
Madagascar logo. Conservation
Madagascar's varied fauna and flora are endangered by human activity. Since the
arrival of humans around 2,350 years ago, Madagascar has lost more than 90
percent of its original forest. This forest loss is largely fueled by tavy, a
traditional slash-and-burn agricultural practice imported to Madagascar by the
earliest settlers. Malagasy farmers embrace and perpetuate the practice not
only for its practical benefits as an agricultural technique, but for its
cultural associations with prosperity, health and venerated ancestral custom.
As human population density rose on the island, deforestation accelerated
beginning around 1400 years ago. By the 16th century, the central highlands had
been largely cleared of their original forests. More recent contributors to the
loss of forest cover include the growth in cattle herd size since their
introduction around 1000 years ago, a continued reliance on charcoal as a fuel
for cooking, and the increased prominence of coffee as a cash crop over
the past century. According to a conservative estimate, about 40 percent
of the island's original forest cover was lost from the 1950s to 2000, with a
thinning of remaining forest areas by 80 percent. In addition to traditional
agricultural practice, wildlife conservation is challenged by the
illicit harvesting of protected forests, as well as the state-sanctioned
harvesting of precious woods within national parks. Although banned by
then-President Marc Ravalomanana from 2000 to 2009, the collection of small
quantities of precious timber from national parks was re-authorized in
January 2009 and has dramatically intensified under the administration of
current head of state Andry Rajoelina as a key source of state revenues to offset
cuts in donor support following Ravalomanana's ouster. It is anticipated
that all the island's rainforests, excluding those in protected areas and
the steepest eastern mountain slopes, will have been deforested by 2025.
Habitat destruction and hunting have threatened many of Madagascar's endemic
species or driven them to extinction. The island's elephant birds, a family of
endemic giant ratites, went extinct in 17th century or earlier, most probably
due to human hunting of adult birds and poaching of their large eggs for food.
Numerous giant lemur species vanished with the arrival of human settlers to
the island, while others became extinct over the course of the centuries as a
growing human population put greater pressures on lemur habitats and, among
some populations, increased the rate of lemur hunting for food. A July 2012
assessment found that the exploitation of natural resources since the 2009 coup
has had dire consequences for the island's wildlife: 90 percent of lemur
species were found to be threatened with extinction, the highest proportion of
any mammalian group. Of these, 23 species were classified as critically
endangered. By contrast, a previous study in 2008 had found only 38 percent
of lemur species were at risk of extinction.
In 2003 Ravalomanana announced the Durban Vision, an initiative to more
than triple the island's protected natural areas to over 60,000 km2 or 10
percent of Madagascar's land surface. As of 2011, areas protected by the state
included five Strict Nature Reserves, 21 Wildlife Reserves and 21 National Parks.
In 2007 six of the national parks were declared a joint World Heritage Site
under the name Rainforests of the Atsinanana. These parks are Marojejy,
Masoala, Ranomafana, Zahamena, Andohahela and Andringitra. Local timber
merchants are harvesting scarce species of rosewood trees from protected
rainforests within Marojejy National Park and exporting the wood to China for
the production of luxury furniture and musical instruments. To raise public
awareness of Madagascar's environmental challenges, the Wildlife Conservation
Society opened an exhibit entitled "Madagascar!" in June 2008 at the Bronx
Zoo in New York. References
Bibliography Bradt, Hilary. Madagascar, 10th Ed.: The
Bradt Travel Guide. London: Bradt Travel Guides. ISBN 978-1-84162-341-2.
Davies, S.J.J.F.. "Birds I: Tinamous and Ratites to Hoatzins". In Hutchins,
Michael. Grzimek's Animal Life Encyclopedia 8. Farmington Hills, MI:
Gale Group. ISBN 0-7876-5784-0. Ellis, William. Three visits to
Madagascar during ... 1853-1854-1856. London: Oxford University.
Emoff, Ron. "Spitting into the wind: Multi-edged environmentalism in Malagasy
song". In Dawe, Kevin. Island Musics. New York: Berg. ISBN 978-1-85973-703-3.
Hillstrom, Kevin; Collier Hillstrom, Laurie. Africa and the Middle East: a
continental overview of environmental issues. Santa Barbara, CA: ABC-CLIO.
ISBN 978-1-57607-688-0. Hobbes, Joseph; Dolan, Andrew. World
Regional Geography. Belmont, CA: Cengage Learning. ISBN 978-0-495-38950-7.
Kull, Christian. [Isle of Fire: The Political Ecology of Landscape Burning
in Madagascar, Issue 246 Isle of Fire: The Political Ecology of Landscape
Burning in Madagascar, Issue 246] . Chicago: University of Chicago Press.
ISBN 9780226461410. External links
Madagascar Wildlife Conservation WildMadagascar.org