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The mammal order Pholidota includes just a single family, Manidae. Included in this family is a single genus, Manis, which includes eight species, all of which are known as pangolins (or scaly anteaters) and live in Africa and Asia. The four African species are Manis (Uromanis) tetradactyla, M. (Phataginus) tricuspis, M. (Smutsia) gigantea, and M. (Smutsia) temmincki. The four Asian species are M. (Manis) crassicaudata, M. (Manis) pentadactyla, M. (Paramanis) culionensis, and M. (Paramanis) javanica. The indicated subgenera have sometimes been treated as distinct genera and M. culionensis, from the Philippines, has sometimes been treated as a synonym of M. javanica.
Pangolins have long, muscular tails (head and body length ranges from around 300 to 880 mm; tail length from 350 to 880 mm). All pangolins use their tails as powerful weapons to defend themselves and some pangolins may sometimes walk on just the hind legs, using the heavy tail as a brace. The tail and every outer surface of a pangolin is protected by horny scales, but the face, throat, belly, and inner limbs are naked or covered with ordinary mammalian hair. Three or four hairs are present at the base of each scale in the Asian species, but these hairs are not present in the African pangolins. "Pangolin" is a Malay name meaning "one that rolls up", which describes the defensive strategy employed by all pangolins of curling up into a tight ball, converting themselves into spheres of overlapping armor (one published report described a pangolin [M. javanica] curling itself into a ball and rolling rapidly down a slope!). The tubular skull provides extra protection as a result of its being made of thick, dense bone. All pangolins can travel on the ground, but arboreal species feed and sleep in rainforest trees. The much heavier terrestrial forms have dense massive scales reflecting their greater exposure to more formidable predators. Arboreal pangolins may weigh as little as 2 kg, whereas the terrestrial Giant Pangolin (S. gigantea) can exceed 30 kg.
Pangolin heads are relatively small, consisting largely of a nose with a small mouth. Pangolins have no teeth and cannot chew. All pangolins feed almost exclusively on termites and ants, which are captured with the sticky tongue then swallowed and ground up with tiny pebbles or sand in the hardened gizzard-like stomach. The worm-like tongue is as long as the head and body and when not extended folds back into a throat pocket that visibly bulges and empties as the animal feeds. The tongue is very sticky and associated with enormous salivary glands, requiring frequent drinking. The remarkable structure and attachment of the tongue allow it to travel down a hole in a termite mound, then whip back into the mouth covered in termites. The nostrils and ear openings can be closed and thick lids protect the eyes. All species have sharp claws on their forefeet, which they use to open termite mounds and to rip open hollow branches and trunks (they are reportedly also used by fighting males and possibly in defense). The hind limbs of pangolin species with different body sizes and habits are far more divergent than the forelimbs.
Despite their superficial resembance to the armadillos of the New World, pangolins and armadillos are not closely related. Their resemblance is due to parallel adaptations rather than recent common ancestry of the two groups.
In Africa, the arboreal Long-tailed Pangolin (M. tetradactyla) and Tree Pangolin (M. tricuspis) as well as the Giant Pangolin (M. gigantea) are closely tied to water; the Ground Pangolin (M. temmincki) is more arid-adapted, but only penetrates dry areas on the margins of its range in the Kalahari, Sudanic, and Somali arid regions.
Pangolins inhabit forests and thick bush as well as open or savannah country. Most species are nocturnal, but some are diurnal. Pangolins are mostly silent, although they may make hissing or puffing sounds. Male pangolins apparently defend scent-marked territories that enclose the home ranges of several females. Ground burrows are around 15 to 20 cm in diameter with a depth of several meters and terminating in a circular chamber as much as 2 m in circumference. Burrow entrances are generally closed with dirt when occupied. Giant Pangolin burrows may be as much as 5 m deep and 40 m long.
Young are born in burrows or arboreal hollows and subsequently are transported on their mother's tail. or back. African pangolins typically have just a single offspring at a time, but Asian species may have up to three.
Pangolin populations have suffered greatly from hunting for meat, skins, and scales, which are valued in traditional medicine in both Asia and Africa, as well as from habitat loss and possibly from high sensitivity to insecticides.
(Nowak 1991 and references therein; Kingdon 1997)