The largest land mammal on earth, Elephant

 
Elephants are large mammals of the family Elephantidae and the order Proboscidea. Two species are traditionally recognised, the African elephant (Loxodonta africana) and the Asian elephant (Elephas maximus). Elephantidae are the only surviving family of the order Proboscidea; other, now extinct, families of the order include mammoths and mastodons. Male African elephants are the largest surviving terrestrial animals and can reach a height of 4 m (13 ft) and weigh 7,000 kg (15,000 lb). All elephants have several distinctive features the most notable of which is a long trunk or proboscis, used for many purposes, particularly breathing, lifting water and grasping objects. Their incisors grow into tusks, which can serve as weapons and as tools for moving objects and digging. Elephants' large ear flaps help to control their body temperature. Their pillar-like legs can carry their great weight. African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs.The largest land mammal on earth, the African elephant weighs up to eight tons. The elephant is distinguished by its massive body, large ears and a long trunk, which has many uses ranging from using it as a hand to pick up objects, as a horn to trumpet warnings, an arm raised in greeting to a hose for drinking water or bathing.

Elephants are herbivorous and can be found in different habitats including savannahs, forests, deserts and marshes. They prefer to stay near water. They are considered to be keystone species due to their impact on their environments. Other animals tend to keep their distance, predators such as lions, tigers, hyenas and wild dogs usually target only the young elephants (or "calves"). Females ("cows") tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups are led by an individual known as the matriarch, often the oldest cow. Elephants have a fission-fusion society in which multiple family groups come together to socialise. Males ("bulls") leave their family groups when they reach puberty, and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate and enter a state of increased testosterone and aggression known as musth, which helps them gain dominance and reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness and show empathy for dying or dead individuals of their kind.
Asian elephants differ in several ways from their African relatives. They are much smaller in size and their ears are straight at the bottom, unlike the large fan-shape ears of the African species. Only some Asian male elephants have tusks. All African elephants, including females, have tusks. Elephants are either left or right-tusked and the one they use more is usually smaller because of wear and tear. The Asian elephant has four toes on the hind foot and five on the forefoot, while the African elephant has three on the hind foot and five on the forefoot.
Led by a matriarch, elephants are organized into complex social structures of females and calves, while male elephants tend to live in isolation. A single calf is born to a female once every 4-5 years and after a gestation period of 22 months—the longest of any mammal. These calves stay with their mothers for years and are also cared for by other females in the group.
The two species of elephants—African and Asian—need extensive land to survive. Roaming in herds and consuming hundreds of pounds of plant matter in a single day, both species of elephant require extensive amounts of food, water and space. As a result, these large mammals place great demands on the environment and often come into conflict with people in competition for resources.