Description of physical Structure of Asian Elephant
- 2000-5500 kg. (4,500-12,000 lbs.)
- Largest living land mammal (several whales are larger).
- 5.5-6.5 m. (18-21 ft.)
- 1.2-1.5 m. (4-5 ft.)
- Tail of Elephas m. boreensis longer than other subspecies - almost touches the ground.
- Female: 2.24 m. (8 ft.)
- Male: 3.2 m. (10 ft.)
- A bull displayed at the Smithsonian's National Museum of Natural History measured 4 m (13 ft.) at the shoulder
All elephants have versatile proboscis or trunk, columnar legs, thick skin (pachy-dermous), and sparse patches of hair.
Smaller than African elephants.
Convex or level back vs more concave in African elephant.
Highest point is at head vs at shoulder in African elephant.
Sri Lankan subspecies is the largest.
- Skin has several textures depending according to location on body
- Bumpy skin on most of body
- Smooth skin on ears, lips, eyelids, genitalia
- Rough texture isn't found in skin of other mammals.
- Generally smoother than the African Elephant’s
- Thick skin - protects against insect bites and weather
- Usually gray. May have white or pink blotches on ears, trunk, head or neck
- Sumatran elephants lightest in color and have least depigmentation (loss of color).
- Sri Lankan elephants darkest and have distinct depigmentation
- Frequently bathe with water, mud or soil to control body temperature.
- Equals about 15% body weight
- Skull weight equals about 52 kg. (115 lbs.); extensive honeycomb-like spaces reduce skull's weight
- Very short neck brings head close to the center of gravity. Cannot turn head side to side
- Sumatran elephant has 20 sets of ribs, others subspecies have 19 (last 4 are floating)
- African Elephant has 21 sets of ribs
- Side-to-side movement of limbs from the center of the body restricted.
- Increases stability and prevents falls, which can be fatal.
- Feet rest on pads of shock-absorbent, elastic connective tissue, which help support weight
- 34 tail vertebrae
- 33 in African elephants.
- Chewing surfaces of teeth are closed, compressed loops; those of African Elephant are diamond-shaped
- Teeth have a high crown with rasp-like surface, which allows them to chew high fiber materials.
- 26 teeth over lifetime: 2 upper incisors (tusks), 12 deciduous premolars, 12 molars. No canines.
- Six sets of 4 molars molars during lifetime
- Average replacement ages are at 1.5 to 2 years, 6 years, 8 to 10 years, 20 to 25 years and at 50 to 6 0 years.
- The final set is usually lost between 60 and 70 years of age. (Eltringham,1991, p.40).
- Because the teeth change in size and shape throughout life, age of an individual can be estimated.
- Function: dig for water, salt or rocks, debark trees, serve as weapons, protection or rests for the trunk, move branches
- Favors either left or right tusk . One tusk usually shows more wear than the other.
- Elephant incisors develop into tushes and tusks
- Tushes barely extend past the mouth; replaced by permanent tusks
- Permanent tusks in place by 6 to 12 mos; grow about 17 cm (7 in. )/yr. depending on nutrition
- Large tusks up to 1.8 m (5.9 ft); slimmer and straighter than African's
- Longest tusk on record: 3 meters (119 in.).
- Heaviest weighed 39 kg. (86 lbs)
- Females are tuskless, or have tushes
- Proportion of tuskless males varies widely (0 to 100%). They are called "makhnas."
- Both male and female African elephants usually have tusks
- Tusk microstructure seen in cross section ("Schreger lines") allow identification of various elephant taxa.
- Technical term is “proboscis," meaning "before the mouth" (Greek)
- Tool for lifting, smelling, spraying dust, grass, and water on body
- Used to transfer water to mouth, not used like a drinking straw
- Also used for sound production, courtship, calf assurance during nursing, behavioral signals and displays
- More "rings" (annulations) than in African Elephant's and perhaps is more extendable
- Formed by a fusion of the nose and upper lip
- One prehensile “finger” at tip of trunk (mammoths had one also); African elephant has two "fingers"
- Three types of tactile receptors at tip; most sensitive part of the trunk
- Contains as many as 150,000 muscle units
- Muscle masses aligned in radial, longitudinal, and oblique layers for extraordinary flex-ibility
- Tongues of vertebrates, arms of octopus and tentacles of squid have similar flexibility
- 70% of air inhaled is through the trunk, the rest comes through the mouth.
- Uses trunk to transfer water to mouth, not used for drinking;can hold up to 5 liters (1.3 gal) water
- Trunk tip's contain nerve endings with heightened sensitivity to vibrations
- When placing trunk tip on ground, can detect vibrations of running animals.
- Smaller than the African elephant's.
- E.m. borneensis has larger outer ear (pinna) than other subspecies
- Thermo regulation - positive correlation between the number of times an elephant flaps its ears and air temperature.
- Cochlea's curved structure may facilitate sensitivity to low frequencies.
- Can hear approximately 8Hz. – 12 kHz
- For comparison: humans hear up to 19kHz and dogs to 44 kHz
- Represent best sensitivity of all mammals so far tested (Langbauer 2000)
- May be able to detect seismic vibrations from thunderstorms, animal hooves through feet.
- Two mammary glands produce milk that is 83.82% water, 11.82% albuminoids and sugar, 3.89% fat and 0.47% ash or mineral matter.
- Cheek (temporal) glands located midway between eyes and ears. Drain during times of excitement such as fighting, mating or in musth (once or twice a year)
- Produce pheromones that stimulate other elephants' behavior
- Present in both males and females; much more active in males
- Tear ducts are vestigial. Herderian glands lubricate the eyes.
- Eye is small in relation to body size
- Ability to see color - probably similar to humans who are color blind
- Total visual field is a sweep of 313° out of 360° with a 47° blind spot (compared to 357° visual field for a horse)
- No true tear ducts
- Good in dull light, considerably reduced in bright light.’
- Males have large trunk bases, bulges below and in front of eyes, and swelling above the eyes. Females have narrower trunk bases and lack prominent bulge above eyes
- Male back is more convex and curves more gradually into hindquarters; female's is straighter and "boxier" with vertical hindquarters.
- Males considerably larger than females of same ages.
Other Physical Characteristics:
- Folds in brain resemble that of humans and porpoises
- Highly sensitive Jacobson's organ on roof of mouth used for detecting sex pheromones
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