SEE ALL WILDLIFE ARTICLES
|
African Elephant
~ Loxodonta Africana
By Daniel James Devine
Out of the thicket thunders a massive beast, with tusks like spears and a trunk like
a tree. Its ears flap wildly, like banners in an ancient war charge.
Small amber eyes burn with undaunted resolution. It trumpets and begins to
charge.
Then it skids, stops, sniffs the air, and saunters
down to a nearby mud hole. And we all say, fickle.
Elephant breeding herd
Bigger is Better
In the world of elephants, bigger is definitely better, even if it means just
looking big. Male African elephants continue to grow throughout their 70
years, and can reach 7½ tons (more than two Hummers).
Although they
are known mostly for their size and shape, elephants possess a variety of
amazing abilities that confound evolutionism, and lead complex social lives
carried on through unique forms of communication, such as trunk touch and
subsonic calls.
A Closer Look
First let's look at the elephant's body, starting at the
bottom--the feet.
Elephant walking, side view
The elephant's foot is a spongy pad with
four or five toes and toenails. The pad acts like a cushion with each step,
absorbing the impact and taking some strain off the leg.
Like the pillars of a palace, an elephant's legs are positioned directly under it.
In contrast, the legs of most other mammals, such as dogs or horses, are in an
angular position. In addition elephant bones are semi-solid, lacking the normal
marrow cavity in favor of a perforated bone tissue that provides optimum
strength and still allows blood cell production.
Both its legs and
skeleton are suited to handle its massive weight, while not sacrificing too much
in mobility. An elephant can walk forward and backward, amble at 25 mph,
negotiate steep terrain, swim in deep water, and stand on its hind legs with the
help of a tree.
Notoriously thick-skinned (1 inch in some
places), elephants are grey and rough to the touch, almost resembling
stone. However, elephant skin is very sensitive, and they take pains
to keep themselves cool and free of pests by wallowing in mud and flinging dust
on themselves with their trunks.
Elephant wallowing in mud
Elephant enjoying dust bath
Now, I know this doesn't sound like the cleanest way to go, but the mud is actually very affective at blocking UV
radiation and heat, which elephants find much less comfortable than dirt.
Ticks are especially bothersome, and elephants often have favorite scratching
trees for noninvasive operations. Their skinny tails help keep off flies
in the hindquarters, but when there is a serious itch, a sit and a rub on the
nearest termite mound will do.
A Word About the Hair
Elephant's Tail
The extinct
wooly mammoth had loads of hair, suiting him to a cold environment, but African
and Asian elephants have only sparse brown hair here and there on their bodies,
with concentrated tufts on places like the mouth and tail.
The lack or
abundance of hair are just traits of natural selection, the end products of a
common elephant ancestor.
Other such traits are ears (larger in African
elephants than in Asians), hind toes (Asians usually have four, Africans five),
and teeth (African elephants sport less narrow teeth than their cousins, thus
they are called Loxodonta -- "Lozenge-tooth").
The Head
Since an elephant head is so large, weighing hundreds of pounds, it is supported
with extra muscles along the neck, and the skull has, like bird bones, many tiny
air pockets to keep it light.
Large ears not only boast a remarkable sense
of hearing--more on that in a moment--but function as air conditioners, cooling
the blood of a hot elephant by up to 15 degrees F as it flaps its ears.
Tusks are deeply embedded in the skull and continue to grow throughout an
adult's 60+ year life, although not all Asian elephants have tusks. They
are used for friendly sparring, digging, foraging, scraping or pushing trees, as
protection for the trunk, and occasionally for fighting. They're also a
nice trunk rest, and, well, what do you
do when you have an itch inside your nose?
And the Amazing Trunk
Elephant stripping bark
With estimated muscle counts ranging between 40,000 and
150,000, the trunk of an elephant is the most extraordinary and dexterous nose
in creation.
At once both gentle and strong, a trunk is capable of killing
a lion--or caressing a frightened elephant calf. It can pick leaves, pull
bark off trees, and pick up objects as small as a coin. It can suck up a
gallon of water to squirt into a mouth or on a hot back (Elephants do not drink
through their trunk, but use it to draw the liquid).
With their trunks
elephants throw dust in the air, rub their eyes, greet one another, sound calls,
test uncertain ground, smell danger--or a potential mate--and snorkel.
African elephants have two lobes on the tips of their trunks (Asians have only
one) that act like fingers.
Since elephants spend most of their time
eating and drinking, those fingers get a steady workout, grasping seeds, roots,
fruit, flowers, leaves, branches, bark, grass, and even thorns to pacify an incurable appetite.
Elephants can consume as much 300 pounds
of forage a day, and up to 50 gallons of water. They drink whenever they
can since they may have to go for a couple days or more without water during dry
spells or while traveling. Elephants are fast walkers and some herds have
been observed to cover 120 miles in one day. However, 15 miles is a closer
average for an elephant. More than most of us walk, anyway.
Social Structure
A typical elephant family is comprised of a group of
related females (maybe 2, maybe 40) and their young, including males younger
than about 14. Different families sometimes meet and feed in the same
area. The family is led by the oldest female, the "matriarch", and the others
follow her lead in every circumstance. She decides when to stop, and when
to move on, and where to go.
Elephant herd heading towards river for a drink
Males are less communal, traveling sometimes
among other males and at other times from family to family in search of
mates. About once a year males enter a state of sexual excitement called
musth, and they may fight one another for rights to a female.
Elephant bulls in musth are famously uncontrollable, and take on violent, insane
characteristics--even attacking their caretakers in captivity--and during this
time glands on their cheeks, called the temporal glands, swell and emit a sticky
liquid which can often be seen running down their faces. While in musth
they send out low-frequency calls to other females, and if one responds in the
distance they will follow her.
A female who is "in heat," called estrus
(and whose temporal glands will also be secreting), may not allow a male to
mount her if she discovers he is young and small. Females prefer older
males, and since older males ward off the younger, less experienced ones, it
usually takes years before a young bull successfully produces an
offspring. Once a male and female have met, they will sniff out one
another to decide if the other is eligible, and if so, they will mate.
Breeding
Elephant cow and calf
A female usually bears her first calf between 10 and 20 years old and bears
again every 4-6 years. It takes over a year and a half for an elephant
embryo to develop, but at birth calves can stand within an hour, and swim soon
after.
Baby elephants drink milk from their mother's two breasts until 4-6
years later, when mom bears her next young. Despite a mother's tender care
and the protection of the family, only a few calves live to adulthood.
Communication
Elephants communicate a lot through touch, taste, and
smell. A mother may bat her calf with her tail to make sure he is still
following behind her, or she may turn and shove him as discipline. Two
elephants who meet will "greet" with trunks outstretched, sniffing for clues
about the other. (Incidentally, some scientists say that excited behavior
during greetings may suggest that elephants remember one another, even after
being separated for many years.)
Trunk raised
Elephants on alert will raise their
trunks like periscopes, with the tips pointed toward whatever ill wind is
blowing. They also can make more than 25 various vocalizations.
Trumpets, screams, rumbles, and grunts all send a message, depending on how they
are made.
A series of long, low rumbles may be a signal for the family to
get up and move on. A trumpet may be a show of intimidation; a special
soft hum is a mother's song to her newborn. Some calls are made only by females,
only by males, or by calves.
Infrasonic Sounds
Amazingly, many elephant calls are too low
(15 hertz) for human hearing ability (20 hertz). These infrasonic sounds
are capable of traveling long distances, and most occur in the early morning or
evening hours, when ground air is cool enough to carry the frequency without
interference.
At these times a single call can be heard for 110 square
miles--perhaps advertising a female who is ready to mate. With such
broadcast methods at their disposal elephants are always in touch with one
another. Always moving on a whim.
And sometimes a
little fickle.
- Taxonomy: Kingdom Animalia; Phylum Chordata; Subphylum Vertebrata; Class Mammalia; Order Proboscidea; Family Elephantidae; Genus Loxodonta
("Lozenge-tooth"); Species Loxodonta africana
("Of Africa")
The forest
elephant Loxodonta
cycotis is found in African forests and is considered a separate species
from the elephant found in the savannah, Loxodonta africana, but both are called
African elephants. The Asian elephant is currently categorized in a
separate genus and species: Genus Elephas ("Huge
arc"); Species Elephas maximus ("Large") In
addition the Asian is divided into four subspecies (although some claim they
should be divided further): Elephas maximus maximus,
found in Sri Lanka; Elephas
maximus sumatranus, found in Sumatra and Borneo; Elephas maximus indicus,
the mainland species found throughout South-east Asia; and lastly, the Borneo
pygmy elephant, Elephas
maximus borneensis which was discovered in 2003. Slight variations
exist in each subspecies, but nothing too drastic.
The
famed wooly mammoth, extinct though he is, is a relative of the African and
Asian and claims a genus of his own, Mammuthus.
- Status: The African elephant (including both the forest and savannah
species) is listed as Vulnerable
on the IUCN Red List, one step below Endangered. Exact populations are
uncertain, but it is believed that as much as 80% of the species occurs
outside of protected areas. The Asian elephant is listed as Endangered.
This elephant biofile first appeared in Globelens.com, the burgeoning work of Daniel James Devine,
a writer and researcher with an unsettling amount of curiosity and a love for pictures and prose.
Words: © Daniel James Devine. 2005. Used by Permission -- Pictures: © Scotch Macaskill
If you'd like to find out more about how elephants communicate, you should read this in-depth yet fascinating
academic paper, Social Behaviour and Communication in Elephants.
Return to Wildlife Articles
|