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The Leporidae are a family of mammals that include rabbits and hares, over 60 species in all. The Latin word ''Leporidae'' means "those that resemble ''lepus''" (hare). Together with the pikas, the Leporidae constitute the mammalian order Lagomorpha. Leporidae differ from pikas in that they have short, furry tails and elongated ears and hind legs. The term "leporid" may be used as a noun ("a member of the family Leporidae") or as an adjective ("like members of the Leporidae"). The common name "rabbit" usually applies to all genera in the family except ''Lepus'', while members of ''Lepus'' (almost half the species) usually are called hares. Like most common names however, the distinction does not match current taxonomy completely; jackrabbits are members of ''Lepus'', and members of the genera ''Pronolagus'' and ''Caprolagus'' sometimes are called hares. Various countries across all continents except Antarctica and Australia have indigenous species of Leporidae. Furthermore rabbits, most significantly the European rabbit, ''Oryctolagus cuniculus'', also have been introduced to most of Oceania and to many other islands, where they pose serious ecological and commercial threats. ==Characteristics== Leporids are small to moderately sized mammals, adapted for rapid movement. They have long hind legs, with four toes on each foot, and shorter fore legs, with five toes each. The soles of their feet are hairy, to improve grip while running, and they have strong claws on all of their toes. Leporids also have distinctive, elongated and mobile ears, and they have an excellent sense of hearing. Their eyes are large, and their night vision is good, reflecting their primarily nocturnal or crepuscular mode of living. Leporids range in size from the pygmy rabbit (''Brachylagus idahoensis''), with a head and body length of 25–29 cm, and a weight of around 300 grams, to the European hare (''Lepus europaeus''), which is 50–76 cm in head-body length, and weighs from 2.5 to 5 kilograms. Both rabbits and hares are almost exclusively herbivorous (with exceptions among the members of ''Lepus''), feeding primarily on grasses and herbs, although they also eat leaves, fruit, and seeds of various kinds. They are coprophagous, as they pass food through their digestive systems twice, first expelling it as soft green feces, called cecotropes, which they then reingest, eventually producing hard, dark fecal pellets. Like rodents, they have powerful front incisor teeth, but they also have a smaller second pair of incisors to either side of the main teeth in the upper jaw, and the structure is different from that of rodent incisors. Also like rodents, leporids lack any canine teeth, but they do have more cheek teeth than rodents do. Their jaws also contain a large diastema. The dental formula of most, though not all, leporids is: They have adapted to a remarkable range of habitats, from desert to tundra, forests, mountains, and swampland. Rabbits generally dig permanent burrows for shelter, the exact form of which varies between species. In contrast, hares rarely dig shelters of any kind, and their bodies are more suited to fast running than to burrowing.〔 The gestation period in leporids varies from around 28 to 50 days, and is generally longer in the hares. This is in part because young hares, or leverets, are born fully developed, with fur and open eyes, while rabbit kits are naked and blind at birth, having the security of the burrow to protect them.〔 Leporids can have several litters a year, which can cause their population to expand dramatically in a short period of time when resources are plentiful. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「leporidae」の詳細全文を読む スポンサード リンク
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