African Elephants (Loxodonta africana and L. cyclotis) Fact Sheet: Physical Characteristics

Body shape

• Largest living land mammal
  • Tip of trunk to tip of tail 7-8.8m (23-29 ft)
• Distinguishing features
  • A proboscis or trunk
  • Relatively large ears
  • Long tusks
  • Columnar legs
  • Thick skin (pachydermous)
  • Lack of hair on most of adult body

Head and facial features

• Ears
  • Size
    • Very large; 2 times the size those of the Asian elephant
    • Large surface area aids in thermoregulation (maintenance of body temperature)
      • A positive correlation exists between the number of times an elephant flaps its ears and increasing air temperature
  • Shape
    • Often likened to the continent of Africa
  • Used to communicate in social interactions and provide balance
    • Spread ears indicate threat
    • Position ears to aid balance
  • Acute hearing
    • Hear low frequency sounds better than any animal tested, one study (Heffner & Heffner 1980)
• Trunk
  • Size
    • Length: 6-6.5 ft
    • Weight:150-200 kg (330-440 lb)
  • Structure
    • Fusion of the nose and upper lip
    • 2 nostrils set at the tip
    • Muscles
      • 8 major muscles on each side of trunk
      • 150,000 muscle fascicles (portions of muscles) for the entire trunk
    • No bone or cartilage within the trunk
  • Function (from Shoshani 1992)
    • Nose through which air is inhaled
      • 70% of air inhaled is through the trunk, the rest comes through the mouth
      • May have developed for snorkeling
        • Modern day elephant is only mammal that can remain submerged far below the surface of the water while snorkeling (West 2001) (also discussed in How Elephants Snorkel)
    • Tool for lifting, smelling, spraying dust, grass, and water on body
      • Tip prehensile; capable of grasping objects
      • Small "fingers" on the top and bottom of the trunk aid in securing grip
    • Used for sound production, courtship, calf assurance during nursing, behavioral signals and displays
    • Does not act as a straw
      • Elephants do not "drink" water through the trunk
      • Water is sucked up and squirted into the mouth
        • The trunk can hold more than 8 liters (2 gallons) of water
• Tusks
  • A single pair, most commonly
    • More may result from abnormal branching as a calf
    • Present in both males and females
      • Length approximately equal in both sexes
  • Structure
    • Incisor teeth
      • Unlike those of pigs, hippopotami and walruses whose tusks are specializations of the canine teeth
    • Composed of dentine with small enamel tip
    • Ivory
      • Term “ivory” should be applied only to elephants and mammoths
      • Hardness of ivory depends on the animal’s origin, habitat and sex
      • Use of ivory for piano keys
        • Ivory keys produced from the late 1800s until the early 1900s (Chadwick 1992)
        • A standard keyboard used 1.5 lbs. of ivory
      • A pattern in ivory of crisscross lines forming small diamond shaped areas (Schreger lines) are seen in cross section (Shoshani 1992)
        • These patterns are unique to elephants and mammoths
        • Often used by customs officials to determine source of the ivory

• • Shape
    • Savannah elephant: curved out and forward
    • Forest elephant: point straight down
  • Size
    • Record length and weight
      • Record length: 3.264 m (10 ft 8.5 in)
      • Record weight: 102.7 kg (226 lb 7oz)
    • Average size may be decreasing
      • Data collected during the last few decades suggests a decrease of 1-2 lbs/year (from Shoshani 1992, p. 73)
        • 1970: average tusk weight 26 lb 7 oz
        • 1990: average tusk weight 6 lbs 10 oz

• • Development
    • Continually grow
      • Size may be used to determine age
      • Elephants are “right-tusked” or “left- tusked” (one tusk shows definite wear with age)
    • Growth rate c. 17 cm/year (c. 7 in/year) (Fowler 1992)
  • Function
    • Digging (for water, salt, roots)
    • Stripping tree bark
    • Lifting
    • Marking trees
    • Sexual display
    • Defense and offense
    • Protection for trunk

Skeleton

• Skull
  • Weight in adults averages 52.2 kg (115 lb)
  • Cranium filled with honeycomb-like spaces which allow the large skull to be relatively light-weight
• Neck
  • Short
  • Individuals cannot turn the head completely to the side
• Rib cage
  • 20-21 pairs of ribs
  • Last 4 pairs are floating
• Limbs and feet
  • Orientation of bones in limbs is almost vertical
    • Supports enormous weight but prohibits any type of leaping movement
  • Forefeet are digitigrade (weight is on digits similar to tapirs and hippos)
  • Hind feet semi-plantigrade

Teeth

• Highly specialized dentition(from Vaughn et al. 2010)
  • 2 upper incisors (tusks)
  • Usually six cheek teeth in each half of each jaw in a lifetime
    • Erupt in conveyor-belt fashion, one after another (don't erupt vertically)
    • Only one or two functional in each jaw half at a time
    • Old worn-out teeth pushed forward and out
    • Last set usually lost between 60 and 70 years of age (Eltringham 1991)
  • Molars
    • Replaced as an individual ages
      • May produce 6 sets during a single lifetime
    • Replacement ages
      • 1.5 to 2 years
      • 3.5 to 4 years
      • 8 to 10 years
      • 20 to 25 years
      • 40 to 45 years
    • A single molar can weigh over 5 kg (11 lbs). (Fowler 1993)

Skin

• Color
  • Gray typically
  • Often appear brown because of mud baths
    • Frequent bathing, showering, and powerdering (with dirt) is important for skin care
• Thickness varies
  • Paper thin inside ears, mouth, and anus
  • 1 inch thick on back and head
• Nerves and glands
  • Well-supplied with nerves
  • No visible sweat glands
• Sparsely haired adults
  • Longer hair on tip of tail, chin, elbow and knees
  • Babies are covered with hair which decreases with age becoming short

Feet

• Toes
  • 5 toes on each foot (from Nowak 1999)
    • Outer toes may be vestigial
  • Nails
    • Five nails on each forefoot
    • 3 on each hindfoot
• Foot pads
  • Cushioned
    • Structure helps absorb chock
    • May serve as sensory receptors (from Weissengruber et al. 2006)
      • Vater-Pacinian cells in the cushion respond to pressure and vibration
      • Meissner nerve endings in adjacent skin detect light touch

Glands

• Mammary Glands
  • 2 located between forelegs
  • Females produce milk that is 20% fat, 7% sugar and 3-4% protein
  • Fat content 5 times higher than in the cow
• Scent glands (temporal glands)
  • Located on the cheeks between the eye and ear are modified sweat glands
  • Produce an oily secretion containing cholesterol, phenol and cresol
    • Secrete throughout the year, becoming especially active in bulls during mating season
  • They can weigh up to 3 kg in males
    • Rarely over 1 kg in females

Internal Organs

• Organs are not proportionately larger than other mammals
• Heart
  • Weight
    • 27 - 46 lb (12-21 kg)
  • Shape
    • Unique, with a double pointed apex instead of the typical cone shaped mammalian heart
      • Manatees and dugongs also have double apex hearts
  • Heart rate
    • 25-30 beats/min, standing
    • 72-98 beats/min, lying down
• Lungs
  • Anatomy unique among mammals
    • Pleural cavity is obliterated by slippery connective tissue
      • In all other mammals, the lungs are surrounded by 2 layers of a thin membrane with a teaspoon of liquid in between
    • Enables elephants to withstand the extreme differences in pressure above and below water without rupturing blood vessels in the lining of the lungs
      • Animal can swim underwater using its trunk as a snorkel
      • Elephants' closest relatives are manatees, dugongs and sea cows that live full-time in the water
  • Respiratory rate
    • 4-6 breaths/min, when calm
    • Doubles when active

• Lack gall bladder
• Testes
  • Located inside abdomen near the kidneys
• Brain
  • Weight over 11 lb
    • 1/500th of the body weight
    • Human brain weighs about 1.6 kg (3 lbs 8oz) or 1/50th of the body weight

Eyesight

• Eyesight poor
  • Best in dim light
• Tear ducts are vestigial
  • Harderian glands (accessory lachrymal glands associated with the nictitating membrane or third eyelid) lubricate the eyes

Distinguishing features of savannah and forest elephants

• Body shape
  • Savannah elephants more "slender"
    • Back markedly concave
  • Forest elephants more compact
    • Back straight

Elephant trunks are used for lifting heavy objects, snorkeling in water, and communicating through touch.

A trunk can reach up to 6.5 feet in length and weigh as much as 440 pounds. These helpful appendages are formed by a fusion of the nose and upper lip. Eight muscles on either side give the animals great dexterity.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Chadwick (1992)
Eltringham (1991)
Estes (1990)
Fowler (1993)
Grubb & Groves (2000)
Heffner & Heffner (1980)
Mikota (1994)
Nowak (1999)
Shoshani (1992)
Vaughn et al. (2010)
West (2001)