Badgers are nocturnal and elusive, but remain one of the UK's favourite mammals. Like humans, they are omnivorous, although unlike us, they eat several hundred earthworms every night. Badgers are socialcreatures and live together in large underground setts, comprised of a series of interlocking tunnels with nest chambers, toilets and several entrances. They inherit these setts from their parents, while always expanding and refining them. The resulting huge tunnel systems are, in some cases, centuries old.
The naked mole rat (Heterocephalus glaber) also known as the sand puppy or desert mole rat, is a burrowing rodent native to parts ofEast Africa and is the only species currently classified in the genus Heterocephalus.[2] The naked mole rat and the Damaraland mole ratare the only known eusocial mammals.[3] It has a highly unusual set of physical traits that enable it to thrive in an otherwise harsh underground environment; it is the only mammalian thermoconformer,[4] has a lack of pain sensation in its skin, and has very low metabolicand respiratory rates.
Typical individuals are 8 to 10 cm (3 to 4 in) long and weigh 30 to 35 grams (1.1 to 1.2 oz). Queens are larger and may weigh well over 50 grams (1.8 oz), the largest reaching 80 grams (2.8 oz). They are well-adapted to their underground existence. Their eyes are quite small, and their visual acuity is poor. Their legs are thin and short; however, they are highly adept at moving underground and can move backward as fast as they can move forward. Their large, protruding teeth are used to dig, and their lips are sealed just behind the teeth to prevent soil from filling their mouths while digging. About a quarter of their musculature is used in the closing of their jaws whilst they dig - about the same proportion as found in the human leg.[5] They have little hair (hence the common name) and wrinkled pink or yellowish skin. They lack an insulating layer in the skin.
Badgers are short-legged omnivores in the family Mustelidae which also includes the otters, polecats, weasels and wolverines. The 11species of badger are grouped in three subfamilies: Melinae (9 Eurasian badgers), Mellivorinae (the honey badger or ratel) and Taxideinae (the American badger). The Asiatic stink badgers of the genus Mydaus were formerly included within Melinae (and thus Mustelidae), but recent genetic evidence[1] indicates these are actually members of the skunk family, placing them in the taxonomic family Mephitidae.
Badgers include the species in the genera Meles, Arctonyx, Taxidea and Mellivora. Their lower jaws are articulated to the upper by means of transverse condyles firmly locked into long cavities of the skull, so dislocation of the jaw is all but impossible. This enables the badgers to maintain their hold with the utmost tenacity, but limits jaw movement to hinging open and shut, or sliding from side to side without the twisting movement possible for the jaws of most mammals.
Badgers have rather short, fat bodies, with short legs for digging. They have elongated weasel-like heads with small ears. Their tails vary in length depending on species; the stink badger has a very short tail, while the ferret badger's tail can be 46–51 cm (18–20 in) long, depending on age. They have black faces with distinctive white markings, gray bodies with a light-coloured stripe from head to tail, and dark legs with light coloured stomachs. They grow to around 90 centimetres (35 in) in length including tail. The European badger is one of the largest; the American badger, the hog badger and the honey badger are generally a little smaller and lighter. The stink badgers are smaller still, and the ferret badgers are the smallest of all. They weigh around 9.1–11 kg (20–24 lb) on average, with some Eurasian badgers weighing in at around 18 kg (40 lb).[2]
No comments:
Post a Comment