African Elephant

Loxodonta africana

P1030390 300x225 African ElephantSuperorder:  Paenungulata

Order:  Proboscidea

Family:  Elephantidae

Genus:  Loxodonta

Species:  africana

Sub-species:  africana

General Description/Adaptations:
No general description is necessary for this animal.

Males and females both have tusks, but can be distinguished by size, as well as forehead shape – bulls have rounded forehead, cows have angular forehead. (Walker, p. 114)

Loxodonta refers to the enamel pattern on the molars.  They have six sets of molars – as each set gets worn down, the next set pushes forward.  When they are out of molars, they die. (Walker, p. 120)

Probably evolved from the forest elephant, and then had a large increase in size due to the need to eat lower-quality vegetation. Color can range from almost black to gray to pink.  The large, rounded ears are used for hearing, communication, and cooling. (Kingdon, p. 303)

Tusks are oversized incisors, and continue to grow throughout the life of the animal.  Males’ tusks are more developed than female. Average tusk weight at 60 years is 61 kg for males and 9.2 kg for females.  Record weights are 106 kg and 25 kg, with a record length of 355 cm.  (Estes, p. 259)

Size: (Kingdon, p. 305)
Weight:  Female 2,200 – 3,500 kg; Male 4,000 – 6,300 kg

Shoulder height:  1.6 – 2.4 meters

Habitat:
They are shade-dependent during the hot and dry season, which may be a result of their relatively recent evolution out of the forest (10 – 20,000 years ago. Will they become less water and shade-dependent over time?).  Elephants have a huge impact on their habitat, changing entire plant communities, creating waterholes, creating paths through forests, ploughing soil and excavating caves for salt.  At this time this subspecies is predominantly found in savannah parks with access to year-round water. (Kingdon, p. 306)

They can live in a wide variety of habitats, but prefer forest edges that provide both grass and browse, shade and water. (Estes, p. 260)

Range/Parks:
Originally found throughout most of Africa except the driest parts of the Sahara.  They can forage up to 80 km away from water, so can use very marginal areas.  They are now limited to pockets and national parks. (Kingdon, p. 305)

Home Range:
Home range varies by quality of habitat.  Can be as small as 14 sq. km. or as large as 3,500 sq. km. in dry areas. (Estes, p. 261)

Food/Water:
They eat a LOT (180 – 270 kg/day for an adult bull).  80% grasses, but also leaves, mlala palm, bark, roots, wild fruit, acacia seed pods (they are unaffected by the thorns).  They move continuously while feeding, and dig, and strip and gouge bark with their tusks as they travel, and will also use their forelegs to dig for roots and digging water holes.  They can go a number of days without water, but will drink up to 100 liters at a time when they have access. (Walker, p. 119)

They eat up to 5% of their body weight each day, and the vegetation takes about 12 hours to pass through their system. (Kingdon, p. 306)

Focus on grasses and herbs in the rainy season and woody browse during the dry season.  Can be found in open savannah during wet season and in forests or near water during dry season.  Studies of their dung show that they process only 44% of the food they eat, compared to 66% for ruminants. (Estes, p. 260)

They will poop out about 155 kg of dung per day!  (Estes, p. 262)

Breeding:
Females begin breeding after 8 years, and are in estrus for 2-6 days every 3 – 9 years.  They communicate their availability by sending out infrasound signals that can be heard by other elephants up to 4 km away.  All males in the area will come, but musth bulls always win.  They have higher levels of testosterone, and are extremely aggressive.  Musth will last 1 – 103 days, and is indicated by a continual secretion of fluid from the temporal glands and, sometimes, a semi-erect penis dribbling urine and a greenish fluid. (Kingdon, p. 307)

Gestation lasts about 22 months and generally only one young is born – rarely two.  They are able to stand within a few hours, but are unsteady on their feet for several weeks.  Mothers are very attentive and protective, and will even regurgitate water if they think their offspring is getting dehydrated.  Mothers will produce milk for at least 4 years, although young can survive on solid food by 2 years.  They remain dependent for up to 10 years. (Kingdon, p. 307)

Social Organization:
Very complex organization, involving dozens of clan members and potentially hundreds of regular acquaintances.  This is seen as evidence of high intelligence and long memory. (Kingdon, p. 303)

Central unit is mother and offspring.  Females begin producing young between 8 and 20 years old and soon after become “matriarchs”.  Groups tend to split once there are ten daughters and grandparents, but continue to interact and stay in the same areas.  These extended associations are referred to as “bond-groups” or “clans”.  Males are driven off by 10 – 14 years, at which point they may join bachelor groups.  (Kingdon, p. 307)

The matriarch sets foraging direction and speed.  When she stops, they stop.  When she moves on, they move on.  Members of the family unit are rarely more than 50 meters from each other.  When disturbed, they all gather around the matriarch and wait for her lead.  They bunch together nervously when crossing open areas, the matriarch taking the lead and another female bringing up the rear. (Estes, p. 261)

The killing of a matriarch leaves the rest of the group vulnerable due to their disorientation.  They will often let themselves be shot rather than leave the side of the matriarch.  They will try to lift her and help her get away if she is wounded. (Estes, p. 261)

Young males will leave the herd at adolescence, but may remain peripheral, following the maternal herd, for a long time before becoming completely separate.  Bachelor herds may be as large as 144, but are more often 2 – 12. (Estes, p. 261)

Communication:
A charge may be preceded by a rocking motion, and one foot swinging to and fro.  The head may also be shaken with a loud slapping of the ears.  A charge is often accompanied by trumpeting.  During an actual attack, the trunk will be held between or to the side of the forelegs. (Walker, p. 116)

Elephants have recently been found to communicate with low-frequency vibrations, below the level of human hearing.  They do this primarily in the early morning and late evening when air pressure is most conducive to the sound waves traveling.  This “infrasound” was discovered in 1987. (Kingdon, p. 307)

Greeting Ceremony:  Clan members greet each other very warmly.  The primary greeting is for the subordinate member to insert its trunk in to the mouth of the dominant.  They will signal greeting-intention by moving towards each other with their trunks outstretched. (Estes, p. 262)

There is much physical contact between clan members.  Courting elephants will caress each other and twine their trunks, playing ones might trunk-wrestle. (Estes, p. 263)

Vocal:

Rumbling:  deep growling for long-distance communication.  Much of this is below the range of human hearing and can travel over several kilometers.  Quiet rumbles are also used while feeding to stay in contact with one another.  With increased excitement, the rumble can become a bellow or a moan, becoming an intimidating roar when threatening a potential predator.

Trumpeting:  Sound of excitement caused by forcing air through the nose.  Short blast indicates that the animal was startled.  Drawn out may indicate rage.  Is combined with growling and screaming in threat displays.  May also be used as an alarm or call for help, or may be used during intense greeting.

Squealing:  Juvenile distress call.  Elicits an immediate response from mother and other females.

Screaming:  Adult equivalent of the squeal. Used to intimidate opponents along with trumpeting.

Flapping of ears and raising of head is an alert posture.  If these are not combined, though, the flapping of ears could just be temperature regulation, and raising of head and trunk may just be a way of testing the air.  Always look for combinations of behaviors to understand what is being communicated. Head movement up and down or side to side often signals a threat display.  (Estes, p. 263)

Activity Patterns:
They spend 16 – 18 hours per day feeding in order to consume (for males) between 180 and 270 kg of fodder. (Walker, p. 118)

Dry Season:  Move into wet “refuge areas” and flood plains where the grass is still growing.  Once all surface water is gone, they move to hills, forests and rivers.  They feed less and rest more.  This is the period when they do the most de-barking of trees. (Kingdon, p. 306)

Wet Season:  Males make the first move into the areas with new, green growth.  They start out concentrated in these pastures, then disperse.  As the growth of grass increases, they increase the time spent feeding and become more active.  Towards the end of the rainy season, when grass is long everywhere, they are widely dispersed throughout grasslands and savannah. (Kingdon, p. 306)

They sleep 4 – 5 hours per day. (Estes, p. 262)

Lifespan:
50 – 65 years or more. (Kingdon, p. 303)

Sign:
Fresh dung is olive to bright yellow.  The size of the piles is amazing at times (I saw one pile that was almost a meter high).  Walker suggests that to test for freshness, you can push your hand to the center of the pile and see if it is still warm.  Hmmm.  I prefer his color guidelines – it will be dark for up to 5 or 6 hours, then will gradually get lighter.  Stress can cause diarrhea.  Changes in vegetation and seasons will also affect consistency.  During dry season, there will be lower water content. (Walker, p. 120)

Tracks look like somebody set down a row of dinner plates and then picked them up.  Surprisingly narrow trail width for such a large animal.  The forefoot is larger than the hind and is circular or oval, the hind is smaller and longer rather than round.  Forefoot has five toes, hind foot has four. (Walker, p. 120)

When tracking elephants, check for “scuff marks”.  The front foot is lifted, whereas the hind foot is scraped along the ground.  This can help determine direction of travel. (Walker, p. 121)

The pattern of cracks in the feet are individually distinct, so can be used for identifying individuals. (Kingdon, p. 305)

Predators:
The only predator that can threaten an adult elephant is the human.  Calves can be taken by lions or hyenas, but protective mothers make this difficult. (Kingdon, p. 308)

Conservation/Commercial value:
Elephants have had a very difficult history in Africa.  They have been extirpated from many parts of Africa through a combination of ivory poaching, increasing aridity in the Sahara region, and elimination as crop pests.  Legal protection increased from 1920 – 1970, which helped, but then political instability, especially in Uganda, brought them to the brink of extinction.  In the 1930’s and 1940’s, it was estimated that there were between 5 and 10 million elephants in Africa.  By the late 90’s, the population was estimated at between ½ and ¾ million.  It is listed as an endangered species, and the numbers are once again rising in some parts of Africa. (Kingdon, p. 308)

Elephants destroy a great number of trees.  When their populations are spread out, this is good as it leads to habitat diversity and gives smaller browsers access to treetop food sources.  Currently, however, elephant populations are confined to national parks and are having too much impact.  Their conversion of woodlands to grasslands in Murchison Falls has been detrimental both to elephant and rhino populations. (Estes, p. 260)

Other Information:
Should always be approached with caution.  Poor eyesight and hearing, cows are particularly nervous and will especially attack if they are with young.  Bulls are more tolerant and will more likely bluff-charge than actually attack.  Bulls can usually be driven off by throwing clods of dirt or wood onto the ground in front of them or by shouting and clapping one’s hands.  (Walker, p. 116)

References:

Estes, R. (1991). The Behavior Guide to African Mammals. Berkeley, CA:  The University of California Press.

Kingdon, J. (1997). The Kingdon Field Guide to African Mammals. Princeton, NJ:  Princeton University Press.

Walker, C. (1996). Signs of the Wild: A Field Guide to the Spoor & Signs of the Mammals of Southern Africa. (5th Edition). Cape Town, South Africa:  Struik Publishers Ltd.

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