African Elephant Biology
Scroll down to read all about the biology of African elephants or click on one of the links below to access specific information:
Click on part of this elephant to find out more about it. Or uncover the internal organs of an elephant.
An elephant's skull needs to be physically large in order to support the heavy tusks and powerful trunk To minimize weight, the huge skull has a thick wall but contains large honey-comb like spaces.
Male African elephants have a curved forehead. Females are more square in profile.
Elephants have short necks and cannot turn their heads completely sideways.
Elephant eyes are almost identical in size to those of a human. They are normally green or hazel in colour and are protected by long eyelashes. Elephants do not have tear ducts.
In bright sunlight, elephants have poor eyesight. They can see best in dim light.
An African elephant's impressive ears are not just used for hearing. They help regulate the animal's body temperature and may also be spread out wide in threat displays.
Elephant ears contain a large number of blood vessels which are covered by very thin skin. When the ears are flapped, air flows over the blood vessels and the animal loses heat from them. Measuring up to 2m high and over 1m wide, 12 litres of blood can flow through each ear every minute and the animal's body temperature can be reduced by three degrees. An elephant's average body temperature is 35.9 degrees Celsius, just below that of a human (37 degrees).
Elephants have excellent hearing and are thought to be able to communicate with other individuals several kilometres away. They can hear very low frequency sounds (their hearing range is 1-20,000Hz) which are not audible to humans (who have a hearing range of 20-20,000Hz).
The distinctive tears and nicks in elephants' ears are used by scientists to help identify individual animals in the wild.
Elephants breathe through their mouth when their trunk is being used to hold water or dust.
African elephants have 6 sets of molar teeth throughout their life. As each set wears down, a new set grows behind it, moving forwards and upwards. As the old teeth are pushed out, the roots are reabsorbed into the jaw. Find out more about how elephant teeth develop. When elephants eat their jaws and teeth move forwards and backwards not side to side like other herbivores.
There are well-developed salivary glands in the mouth which help to lubricate the coarse vegetation of the elephant's diet.
Elephant tusks are upper incisor teeth which grow very long. They are similar to human teeth, consisting of a central core of pulp which is covered in dentine and encased in bone-like cementum. The internal dentine, making up 95% of the tusk, is the substance commonly referred to as 'ivory'. Find out more about tusks and ivory.
An elephant's trunk is extremely versatile. 70% of the air that elephants breathe is inhaled through the trunk. Like our noses, it can smell the surrounding environment. It can be used to touch and feel objects and other elephants. It can create trumpeting sounds and give physical communication signals. It can be used to break branches from trees, pluck bundles of grass, and suck up and spray water or dust over the body or into the mouth.
Trunks can be over 1.5m long and weigh more than 150 kg. They contain eight major muscles but have 150,000 fascicles (or portions of muscles) which provide amazing dexterity and strength. A trunk can lift more than 250 kg in weight and hold over 8 litres of water.
African Elephants have two prehensile 'fingers' at the end of the trunk which enable them to grasp objects.
The leg bones are placed vertically above each other forming a rigid column when at rest. This helps to support the animal's enormous weight without the risk of its legs buckling but means elephants are unable to run or jump. Their normal walking rate is 6-8 km/h.
The whole mass of the huge head, the trunk and the tusks, is carried by the forelimbs. This image shows how weight is distributed across the animal.
Elephants walk on tip-toe. The animal's weight rests on the tip of each toe and on a fibrous 'cushion' of fatty and connective tissues which acts as a shock absorber. This material absorbs sound, enabling these massive creatures to walk almost silently.
The surface of the foot is very flexible and sensitive, adapting naturally to any irregularities of terrain. The soles of the feet are very thick, horny and superficially cracked. Trackers can use these unique 'footprint' markings to help identify individual animals.
The front feet are larger and more rounded than the hind feet, which are smaller and oval.
The forefeet have 4 or 5 toes, while the hind feet have 3-5. The toenails are made of the same substance found in human toenails (keratin) and are attached to the skin.
The skin thickness varies from paper thin on the inside of the ears, around the mouth and anus to about 2.5cm on the back and parts of the head. Wallowing protects against ultraviolet radiation, parasites and moisture loss. Scratching and bathing are also important behaviours in skin care.
The skin colour is usually gray although often seems brown or reddish from wallowing in mud holes.
An elephant's tail can be up to 1.5 m long. It is used to swat flies away.
Adult elephants may grab a young animal's tail with its trunk in order to guide it. Older calves may also sometimes hold their mothers' tails as they walk.
Scroll down to read about some of an elephant's internal organs, or move your mouse over part of the picture to identify each organ.
An elephant heart can weigh anything from 12 to 28 kgs but amounts to only about 0.5% of the animal's body weight. It has a unique shape with two, rather than one, points.
The heart beats at around 25-30 beats per minute when the animal is standing, increasing slightly when it is lying down. This is much slower than a human heart which averages 70 beats per minute.
Some of an elephant's blood vessels can be over 3m long. In order to prevent their collapse, the animal needs to retain a high blood pressure.
The brain of an adult elephant is the largest of any land mammal and weighs 4-6 kg. This is about 0.1% of its entire body mass. Although human brains are a lot lighter (about 1.5 kg), they make up a greater proportion of body weight (2%). The temporal lobes, known to function as memory centres are quite large in elephants.
Like humans, elephant babies have much smaller brains than those of adults. In most mammals a new-born brain is around 90% of the size of an adult's. In elephants it is 35% and in humans 26%. This probably explains the remarkable learning ability of young elephants.
Only about 44% of the food that an elephant eats is successfully digested. The rest is excreted - take a close look at some elephant dung and you will see undigested grass, seeds and other plant matter.
Elephants eat for around 16 hours a day and a large bull needs about 300 kg of food each day.
The small and large intestines may reach a combined length of 35m. As food works its way through this system, it can take 24 hours to digest a meal.
Elephants take about 4-5 breaths per minute when lying or very calm. This increases to 10 breaths per minute when standing or active (at rest humans take between 12-20 breaths per minute).
The lungs attach directly to the chest cavity and to the diaphragm. Unlike other animals (which use pressure changes to breathe in and out), elephants use muscles to inflate and deflate their lungs.
An elephant expels about 50 litres of urine a day.
An elephant excretes up to 150 kg of waste a day.
Due to their large size elephants reproduce slowly. First conception typically occurs at 10 - 11 years with the interval between calves ranging from 4 - 9 years.
Elephant cows come into oestrous for periods of 2-6 days and will tend to try to avoid approaching bulls.
Bull elephants usually come into musth once a year for a period lasting a few days to several months. During musth, testosterone levels rise, bulls become very aggressive and are more sexually active. Musth bulls can easily be identified by the copious secretion of fluid from the temporal gland on the side of their head and the constant dribble of a pungent greenish liquid from their penis.
Cows may be approached by several bulls who may fight over her. Any musth bulls will dominate other potential suitors.
When a bull finds a potential mate he will use his trunk to test her urine or vulva to see whether she is ready to mate. A receptive cow may walk or even run away from the herd if approached. When a bull finally gets close enough, copulation, with the bull standing on his hind legs, takes less than a minute. The bull guards the female against the approach of other males and this protective behaviour can last for a few hours or even several days.
Gestation is close to 22 months (650 - 660 days).
Mating and births are most frequent during the rainy season. Births take place with the female squatting. Delivery is relatively quick (about half a minute) and the newborn is helped onto its feet by its mother and other females. New born calves weigh about 120kg and are very feeble for the first few days. They remain shaky for several weeks.
The young calf has to locate the teats between the mother's forelegs on its own. While suckling, the trunk hangs to one side. Calves begin trying food other than milk at about 4 months, but are not capable of feeding themselves on solid food until well into their second year. Suckling carries on until the birth of the next calf, which can be up to 8 years.
Before young cows have their own calves they are the main caretakers of other calves within the herd. Known as "allmothers" they will rush to protect or assist any calf in trouble and give comfort to distressed calves. Calves with a greater number of allmothers have a higher survival rate.
Many elephants die from natural causes. Just like humans, they can suffer from life-threatening diseases or abnormalities. They can be affected by environmental conditions such as drought. And they may sustain fatal injuries through accidents or fights with other individuals.
Even if elephants lead a long and healthy life, they will finally die of starvation when their teeth can no longer function.
Scroll down to find out more about elephant mortality, or click on a specific link below:
Serious drought conditions can cause elephant deaths. 'Teenage' animals are often most susceptible as they are not yet large enough to reach the tallest trees and must compete with other species to browse at a lower level. Unlike their younger brothers or sisters, they are no longer able to suckle from their mother.
In 1974, 9,000 elephants starved to death in a severe drought in Tsavo National Park, Kenya. In 2005, several months of drought conditions in Hwange National Park in Zimbabwe caused severe water shortages. Grazing was scarce, waterholes dried up and at least 40 elephants died from starvation and dehydration.
Elephants are relatively free from most fatal diseases. They may die from blood diseases such as septicemia contracted from infected wounds or after childbirth. They are also susceptible to anthrax, tuberculosis, and foot and mouth disease.
In 2004, anthrax outbreaks in the eastern Caprivi region of Namibia and Chobe National Park in Botswana both caused a number of elephant deaths. Anthrax is a bacterial infection contracted through direct contact with infected carcasses or inhalation of anthrax spores. It causes bleeding from the mouth and other body openings and death is sudden.
Due to their longevity, older elephants also suffer from conditions associated with old age such as cardiovascular disease. They are liable to heart attacks and strokes.
Potentially one of the largest living animals on earth, the elephant can live for 65 years or more. The limiting factor for its life expectation is the condition of its teeth. Once its final set of molars has been warn down, the elephant loses the ability to grind and adequately digest the large quantities of coarse vegetation that make up the bulk of his diet. It eventually succumbs to the effects of malnutrition and dies.
Find out more about how elephant teeth develop.
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Did You Know?
- James Stevenson-Hamilton (born in 1867) was appointed the park's first warden on 1 July 1902.