ANIMAL WORLD 

Evolution:

The Asian elephant (Elephas maximus) and the African elephant (Loxodonta africana) are the only elephant species remaining from the order Proboscidea. The third proboscidean species (woolly mammoth (Mammuthus primigenius)), survived into early historical time.

This group is originated in Africa during the Eocene (and later spread to Europe, Asia, and North and South America.) Two main lineages evolved in the early Pliocene: the Elephantidae, to which the two living species belong, and the extinct mastodons of the families Mastodontidae and Stegodontidae.

The Asian elephant and mammoth lineage dispersed from Africa during the mid-late Pliocene, spread throughout Europe and Asia, and became restricted to Asia by the late Pleistocene. The closest living relatives of the two elephant species are the sea cows (manatees and dugongs), whose ancestors separate from the Proboscidea during the Palaeocene.

 

Speciation:

Asian elephants are an example of allopatric speciation, it when A species divides into separate groups, which are isolated from another, and a new species develops:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Biogeography:

 

The current distribution of the Asian elephant lies in the Indian subcontinent and Southeast Asia.

Principal populations are in:

• Burma

• Cambodia

• India

• Indonesia (Sumatra)

• LaosMalaysia

• Sri Lanka

• Thailand

• Vietnam

• Small populations in Bangladesh, Bhutan, southwest China, Indonesia (Kalimantan) and Nepal.

 

 

Animal Behavior:

Male behavior

 

Adult males tend to be solitary; sometimes they may form associations of two or three unrelated bulls. They leave their family at 12-15 years of age and after that time; they may frequently associate with female groups for feeding or mating.

 

Female behavior

 

Within the female groups, the lead individual, decides the group’s pattern of movement, in defending the group against danger, and in monitoring and responding to other approaching elephants. Calves, especially when very young, stay close to their mother. The asian elephants defense mechanism is a circle with the adults on the outside and the babies on the inside. The members of the family unit may separate for short intervals during the day, but will soon regroup.

 

Social interaction

 

Elephants are highly intelligent; individuals of all ages greet, and maintain bonding, by touching their trunk tips to each other’s bodies, rubbing together, and with sound communication and scent. When they are calves playing is a dominant behavior. There is a dominance hierarchy among bulls, generally related to their age, size, and power.

 

Attraction

 

Male elephants enter a periodic state called ‘Musth’. It’s when the temporal gland, located on the side of the head between the ear and the eye, produces a dark fluid (Temporin) with a strong musky odor. A male elephant generally enters musth once a year, for a period of one month. Musth bulls have heightened levels of testosterone and are very aggressive, especially toward other bulls. Females also have a temporal gland, which can occasionally be seen to ooze secretion.

 

Population:

All we really know about Asian Elephants is their location of some populations , and in some cases a really low idea of relative abundance. These situation of low information is due in part to the difficulty in counting elephants in dense vegetation in difficult terrain, different survey techniques being used in different places, and a too-widely held belief that population monitoring is unimportant.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Elephants have relatively poor vision, but highly developed senses of taste and smell. They obtain chemical signals by using their trunks to touch each other’s genitals, mouths, temporal glands, and urine. A remarkable aspect of elephant behavior is their response to injure, sick and dead members of their species. Elephants also have acute hearing and communicate through a wide variety of vocalizations. They are not territorial. They can walk or amble, but cannot canter or gallop. They are also adept swimmers, paddling with all four feet and using the trunk as a snorkel.

 

 

Extinction:

 

The fierce competition for living space by humans has caused a dramatic loss of forest cover reducing Asian Elephant population. A substantial proportion of the world's populations live in or near the present range of the Asian elephant, which leads to elephant-human conflict.

 

The capture of wild elephants for domestic use has become a threat to wild populations where numbers have been seriously reduced.There has been concern about the genetic effects of reduced numbers of male big tuskers. When tuskers are killed, the number of males in a population decreases, resulting in skewed sex ratios.

This may lead to inbreeding and eventually to high juvenile mortality and overall low breeding success. Removing large tuskers also reduces the probability that these longer-ranging loners will mate and exchange genes with females of different sub-populations.