Animals and Conservation

Facts About African Elephants

zooelephantIt is important to recognize that there are two separate types of elephants living in the world today. The Maryland Zoo in Baltimore houses African elephants (Loxodonta africana) who are very different from their Asian elephant (Elephas maximus) cousins. The African elephant (Loxodonta africana) is the largest land animal in the world.  A full-grown female can weigh between 7,000 and 10,000 pounds (three to five tons), reaching heights of 10 feet from the toe to the shoulder while a full-grown male can weigh between 9,000 and 14,000 pounds (four to seven tons) and stand as tall as 14 feet.

An elephant’s four pillar-like legs are well designed to support its massive weight but are not made for extended running or jumping.  An elephant’s feet function to cushion its weight.  Each leg is supported by sponge-like tissue located inside of each foot.  Covering the bottom of each foot is a layer of thick, callous-like skin. There are toenails on the front of the feet for each toe.

The African elephant can be characterized by two exceptionally large ears, a concave back just behind the shoulders, and the presence of tusks in both males and females.  Currently, the African elephant can be found in 37 different countries in Africa and is found on the Threatened Species list due to its declining population numbers as a result of the growing human-elephant conflict.

There are two genetically distinct species of African elephants: the savannah elephant (Loxodonta africana africana) and the forest elephant (Loxodonta africana cyclotis).  Physical differences between the savannah and forest elephants are minimal but very distinct, while their social structure is very similar.  The forest elephant is generally smaller, with rounder ears, and tusks that grow downward.  Normally, forest elephants inhabit the rain forests of central and western Africa and do not overlap the territories of the savannah elephant.  The Maryland Zoo in Baltimore cares for savannah elephants.  There is no record of a forest elephant ever having been maintained in North America.

The African elephant has a number of special adaptations and features that have evolved to support the animal’s behaviors and ecological needs within specific habitat conditions.

Scientific Classification

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Proboscidea
Family: Elephantidae
Genera: Loxodonta
Species: Africana


Skin

skinElephants are known as pachyderms along with hippos and rhinos. The name is derived from the Latin words for “thick” (“pachy”) and “skin” (“derm”) and means, quite literally, “thick-skin.”  Yet although the skin is almost one to two inches thick in some areas, it is less than one millimeter thick in others.  One such area is behind the ears where large amounts of blood vessels are found close to the skin surface.  Warm blood passing through these blood vessels is cooled before recirculating throughout the body.  The skin also helps to disperse an elephant’s body heat, cooling the animal. (Elephants lack sweat glands.)

Elephants have evolved many folds in their skin layers, giving them their “baggy” and wrinkled appearance. The folds serve an important purpose by increasing the overall surface area of the skin, which provides more space to allow for the dispersion of body heat. The wrinkles also are the main reason elephants will mud bathe. The initial cooling of the wet mud helps the elephant cool down instantly. Moisture trapped in all of the wrinkles continues to cool the elephant even after it leaves the mud source.  The mud also protects the elephant’s skin from insects, sun, and moisture loss.


foodDiet

Elephants are herbivores, which means that they only eat plant material.  African elephants eat a huge variety of plant material including grasses, bark, twigs, roots, leaves, fruits, and vegetables.  They are even capable of eating the wooden trunks of trees and logs by chipping off pieces with their tusks or by simply chewing on them with their huge grinding teeth.

Elephants maintain their large size by ingesting an enormous amount of food.  Elephants have highly inefficient digestive systems; nearly 60% of the food they eat goes undigested.  The trunk, tusks, and teeth are highly adapted to help them acquire and process the large amounts of food they need.


Trunk

trunkThe trunk is a modification of the upper lip and the nose combined.  At the end of the trunk are two fingerlike projections that are used to pinch and grip both small and large food items and objects.  The trunk is composed of over 100,000 individual muscles that make it a very strong appendage.  It is an especially amazing adaptation when you consider that the entire human body has less than 800 individual muscles total and that so far, there is no other appendage in the entire animal world known to be as specialized as an elephant’s trunk.

An elephant uses its trunk to suck up water and blow the water into its mouth or onto its body for bathing and cooling purposes.  However, an elephant cannot drink water through its trunk.

In addition to food gathering, drinking, and bathing, the trunk is used for social interactions among herd mates. Elephants make regular contact with one another using their trunks.  Such social interactions may include greeting, caressing, and demonstrations of dominance or submission through subtle positioning of the trunk and different trunk postures.  The trunk can also act as a resonating tube, producing the classic sounds of an elephant trumpet or the sounds of a subtle, reverberating communication rumble.

Perhaps one of the most interesting and yet lesser known facts about an elephant’s trunk is that it is able to detect and distinguish smells several hundred times better than any dog on the planet!  Smell is one of an elephant’s greatest senses and it is all located in the trunk.


tusksTusks

An elephant’s tusks are modified teeth.  They are an elongation of the second incisors and continue to grow throughout the life of the elephant.  Tusks are used for digging, debarking trees, moving objects, making contact with one another, intimidation in dominance displays and for general tools in elephant life.  Males use their tusks when sparring with each other and establishing dominance.

Tusks are made of ivory, which is an incredibly dense form of bone.  It forms in a cross thatch pattern, making it very hard.  There continues to be great demand for ivory tusks because of their unique properties and inherent beauty.  Because they will fetch a high price, poachers continue to illegally kill elephants for their tusks.  This is a major factor in the decline of wild elephant populations worldwide.


teethTeeth

An elephant has only four teeth in its mouth.  They are considered molars and are found in each section of the jaw, two on each side of the mouth.  One tooth can be the size of a brick and has a large surface area of ridges specifically adapted for grinding the large volume of plant material that elephants eat every day.

The teeth get worn down with all the grinding and chewing of fibrous plant material.  To compensate, elephants have evolved replaceable teeth!  An elephant has six sets of teeth in its lifetime.  Replacement teeth come in horizontally rather than vertically like ours.  The older tooth is pushed forward by the newer tooth and eventually falls out in pieces.


Communication

Elephants are considered one of the most intelligent of all land animals.  They have the largest brain of any mammal.  The temporal lobes of the elephant’s brain, which function in recognition, storage, and retrieval of information related to sight, touch, smell, and hearing, are especially large and enormously complex.  Relative to brain size, these temporal lobes appear to be larger, more convoluted, and denser than those of all other animals except humans.  Based on scientific evidence, elephants seem to remember individuals, places, and learned skills for years.  It really is true that “an elephant never forgets.”

Elephants have a highly developed system of communication through sounds.   Elephants produce a broad range of sounds from very low frequency, inaudible infrasound to soft rumbles, trumpets, snorts, roars, and even growls.  The low frequency, or infrasound, allows elephants to communicate across miles.  It is below the range of sound that the human ear can detect.  Elephants detect the low vibrations through their ears, feet, and trunk tip.  Special adaptations in each of these parts of the body pick up and transmit sounds to the hearing centers of the brain.

Elephants also possess one of the most well developed senses of smell in the animal kingdom.  This keen sense of smell is used not only to locate food and water sources but also for communication.  Elephants detect and process many chemical signals in a wide variety of smells throughout their environment.  Sources of odors used in chemical communication between elephants include urine, feces, saliva, and secretions from the temporal gland.


Social Structure

socialElephants are family oriented.  Herds are made up of adult female groups and their offspring.   Older, more experienced females lead elephant families.  They are called dominant females or matriarchs of the herd.  Each herd consists of mostly related females (mothers, aunts, grandmothers, and cousins) and their calves, including young male offspring and occasionally non-related individuals.  Herd sizes range from 20 to 100 individuals.  Female family members stay together for life.

Young males entering adolescence leave their family groups to join bachelor herds, but at times lead a solitary life due to a natural condition called “musth”.  Musth in adult bull elephants is characterized by a significant increase in reproductive hormones (specifically testosterone) that results in strong changes in behavior.  Bachelor herds are important for teaching young males how to become strong, adult bulls.  Adult bulls associate with female herds for breeding purposes only.

One of the most important functions of the female herd is to raise calves.  A female usually has her first calf while in her teens.  A male becomes reproductively mature on average at age 13 but usually won’t breed with females until his late 20s when he is large and strong enough to compete with other bulls for the opportunity.

Once a female is pregnant, gestation lasts about 22 months.  She will give birth to a calf that weighs 150 to 300 pounds and stands two to three feet tall.  At birth, a calf is almost helpless and does not have full use of its trunk yet, but will quickly get to its feet and stand on its own.  The new calf begins nursing within a few hours of standing and quickly gains the strength and coordination needed to keep pace with its mother as she moves around in search of food.  Elephants have a very long adolescence, with a developmental rate similar to humans, and a long life expectancy.

The elephant section of this site was made possible by a gift from C.J. Miller LLC

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