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 Madagascar and other IslandsThe Biological Wealth of an Impoverished Country: Mammals: Page 1 The publication of Mammals of Madagascar, by Nick Garbutt, in 1999 filled a void for a complete guide to all native mammals, illustrated with color photos of most species and major habitats. This supplemented Madascar: A Natural History in 1991, an important reference on mammals and their environment. Conservation work has focused mainly on lemurs, with many organizations involved, including Earthwatch Institute, which sponsors field research; Conservation International; Jersey Wildlife Preservation Trust (based in England); and CARE. Several of these groups sponsored biodiversity studies and helped establish national parks, benefiting thousands of species, including tenrecs and other native mammals. A growing number of Malagasy zoologists are taking part in studies and conservation work, and new programs have been initiated to help local people while conserving mammals and their environments. Certain mammals have received inadequate attention to date, notably bats, rodents and some viverrids, who will undoubtedly benefit from the swell of interest and enthusiasm for Madagascar fauna that has developed in recent years. Filmmakers have recently produced a number of excellent wildlife documentaries, photographing rare species and spreading knowledge and concern about endangered mammals (see Video section).
Among Madagascar's mammals are many primitive forms. The tenrecs' closest relatives are insectivores known as solenodons, native to Cuba, Hispaniola and other vestiges of Gondwana in the Caribbean. Tenrecs and solenodons may have had a common ancestor living on the supercontinent, progenitor of all mammals. The remains of similar species have been found in Africa and South America, indicating that they were once very widespread but died out on all but isolated refuges such as Madagascar and West Indian islands. Tenrecs belong to a family of insectivores, Tenrecidae, related to shrews, moles and hedgehogs, but quite distinct from them. Twenty-seven species of three types of tenrecs make up this family--spiny, furred and otter-shrews (Garbutt 1999). They range in size from the Common Tenrec (Tenrec ecaudatus), which resembles the European Hedgehog and weighs more than 5 pounds, to the shrew-like tenrecs, Microgale genus, weighing less than 2 ounces (Nowak 1999). Tenrecs have some very unusual physical characteristics placing them far from any close mammalian relative. They have variable body temperatures that change with the ambient temperature and, an even more reptilian or avian trait, a cloaca that combines urinal, rectal and generative canals into one (Garbutt 1999).
A striking tenrec is the Lowland Streaked Tenrec (Hemicentetes semispinosus). It and a similar species, the Highland Streaked Tenrec (Hemicentetes nigriceps), weigh about 5 to 7 ounces and measure some 6 inches in length. White stripes run down their backs like skunks, and barbed, porcupine-like spines are detachable (Eisenberg 1975). The Highland species has a stiff, white neck ruff rising several inches at the back of its head that can be stabbed into the nose of an unwary predator (Eisenberg 1975). Family groups forage together and communicate by vibrating quills that produce low-frequency sounds like dry grass being rubbed together; tenrecs can detect these sounds from distances of more than 4 meters (Garbutt 1999). They also make a number of sounds that are audible to humans.
The Aquatic Tenrec (Limnogale mergulus), listed as Endangered in the 2000 IUCN Red List of Threatened Species, inhabits streams and lakes, living at altitudes between 600 and 2,000 meters (Nowak 1999). This 8-inch tenrec has clawed, webbed feet, and a long, thin tail for propelling it through the water to feed on small crustaceans and fish. Its habitat in the central highlands has been greatly affected by human disturbance and deforestation. The Aquatic Tenrec has at least one refuge, the new Ranomafana National Park, created for the bamboo lemurs (Preston-Mafham 1991). In 1990, Dr. David Stone managed to lure an Aquatic Tenrec into a live trap, the first one of its kind seen alive in 25 years (Preston-Mafham 1991). Later, four more were taken and studied in captivity for three weeks prior to being returned to the river Namorona in Ranomafana, one of the few clear, unsilted rivers left in Madagascar (Preston-Mafham 1991). This species requires such streams, and only the preservation of forests, such as that in Ranomafana, will ensure its survival.
Another six species in this family, all shrew-tenrecs of the genus Microgale, are listed in the 2000 IUCN Red List of Threatened Species. These tiny insectivores are found in all parts of Madagascar in areas of heavy vegetation, and have dark, soft fur. They range in size from 1.5 to 5 inches in length, and weigh as little as 1.8 ounces (Nowak 1999). Several of the threatened species are highly restricted in range and habitat, and one, Microgale dryas, listed as Critical, occurs only in Ambatovaky Special Reserve in the northeastern rainforest (Garbutt 1999).
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