The elephants (Elephantidae) are a family in the order Proboscidea in the class Mammalia. They were once classified along with other thick skinned
animals in a now invalid order, Pachydermata.
There are three living species: the African Bush
Elephant, the African Forest Elephant (until recently known collectively
as the African Elephant), and the Asian
Elephant (also known as the Indian Elephant). Other species have become extinct
since the last ice age, which ended about 10,000 years ago, the Mammoth being the most well-known of these.
The word "elephant" has its origins in the Greek ἐλέφας, meaning "ivory" or "elephant".[1]
Elephants are mammals, and the largest land
animals alive today.[2] The elephant's gestation period is
22 months, the longest of any land animal. At birth it is common for an elephant calf to weigh 120 kilograms (265 lb). An elephant may live as long as 70 years,
sometimes longer. The largest elephant ever recorded was shot in Angola in 1956. This male
weighed about 12,000 kg (26,400 lb),[3] with a
shoulder height of 4.2 m (13.8 ft), a metre (3 ft 4 in) taller than the average male African
elephant.[4] The smallest elephants, about the size of a
calf or a large pig, were a prehistoric species that lived on the island of Crete during the
Pleistocene epoch.[5]
Elephants are symbols of wisdom in Asian cultures, and are famed for their exceptional memory and very high intelligence, on
par with cetaceans and hominids.[6][7].
Aristotle once said the elephant was "the beast which passeth all others in wit and mind."
Elephants are increasingly threatened by human intrusion and poaching. Once numbering in the millions, the African elephant
population has dwindled to between 470,000 and 690,000 individuals.[8] The elephant is now a protected species worldwide, with restrictions in place on capture, domestic
use, and trade in products such as ivory. Elephants generally have no natural predators, although
lions may take calves and occasionally adults.[9][10] In some areas, lions may
regularly take to preying on elephants.[11]
Zoology
Comparative view of the human and elephant frames, c1860.
Species
The African Elephant genus contains two (or,
arguably, three) living species; whereas, the Asian
Elephant species is the only surviving member of its genus, but can be subdivided into three subspecies.
African elephants, at up to 4 m (13 ft 1 in) tall and weighing 7500 kg (8.27 short tons),
are usually larger than the Asian species and they have bigger ears. Both male and female African elephants have long tusks,
while their Asian counterparts have shorter ones, with those of females vanishingly small. African elephants have a dipped back,
smooth forehead and two "fingers" at the tip of their trunks, whereas the Asian have an arched back, two humps on the forehead
and only one "finger" at the tip of their trunks.
African elephants are further subdivided into two populations, the Savanna and
Forest, and recent genetic studies have led to a reclassification of these as
separate species, the forest population now being called Loxodonta cyclotis, and the Savanna (or Bush) population termed
Loxodonta africana. This reclassification has important implications for conservation, because it means that where
previously it was assumed that a single and endangered species comprised two small populations, if in reality these are two
separate species, then as a consequence, both could be more gravely endangered than a more numerous and wide-ranging single
species might have been. There is also a potential danger in that, if the forest elephant is not explicitly listed as an
endangered species, poachers and smugglers might be able to evade the law forbidding trade in endangered animals and their body
parts.
The Forest elephant and the Savanna elephant can hybridise – that is, breed together – successfully, though their preferences
for different terrains reduce such opportunities. As the African elephant has only recently been recognized to comprise two
separate species, groups of captive elephants have not been comprehensively classified and some could well be hybrids.
Successful hybridisation between African and Asian Elephant species is much more unlikely, as is animal hybridization across
different genera in general. In 1978, however, at Chester Zoo, an Asian elephant cow gave
birth to a hybrid calf sired by an African elephant bull (the old terms are used here as these events pre-date the current
classifications). "Motty", the resulting hybrid male calf, had an African elephant's cheeks, their
ears (large with pointed lobes) and legs (longer and slimmer), but the toenail numbers, (5 for each front foot, 4 hind) and the
single trunk finger of an Asian elephant. His wrinkled trunk was like that of an African elephant. His forehead was sloping with
one dome and two smaller domes behind it. The body was African in type, but had an Asian-type centre hump and an African-type
rear hump. The calf died of infection 12 days later. It is preserved as a mounted specimen at the British Natural History Museum, London. There are unconfirmed rumours of three other hybrid elephants
born in zoos or circuses; all are said to have been deformed and none survived.
African Elephant
-
African bush (savanna) elephant in
Mikumi National Park,
Tanzania.
The Elephants of the genus Loxodonta, known collectively as African
elephants, are currently found in 37 countries in Africa.
African elephants are distinguished from Asian elephants in several ways, the most noticeable being their ears. Africans' ears
are much larger and are shaped like the continent of their origin. The African is typically larger than the Asian and has a
concave back. Both African males and females have external tusks and are usually less hairy than their Asian cousins.
African elephants have traditionally been classified as a single species comprising two distinct subspecies, namely the
savanna elephant (Loxodonta africana africana) and the forest elephant (Loxodonta africana cyclotis), but recent
DNA analysis suggests that these may actually constitute distinct
species.[12] While this split is not universally accepted
by experts[13] a third species of African elephant has also
been proposed.[14]
Under the new two species classification, Loxodonta africana refers specifically to the Savanna Elephant, the largest
of all elephants. In fact, it is the largest land animal in the world, standing up to 4 m (13 ft) at the shoulder and
weighing approximately 7,000 kg (7.7 tons). The average male stands about 3 m (10 ft) tall at the shoulder
and weighs about 5500–6000 kg (6.1–6.6 tons), the female being much smaller. Most often, Savanna Elephants are found in
open grasslands, marshes, and lakeshores. They range over much
of the savanna zone south of the Sahara.
The other postulated species is the Forest Elephant (Loxodonta cyclotis). Compared with the Savanna Elephant, its ears
are usually smaller and rounder, and its tusks thinner and straighter and not directed outwards as much. The Forest Elephant can
weigh up to 4,500 kg (10,000 lb) and stand about 3 m (10 ft) tall. Much less is known about these animals
than their savanna cousins because environmental and political obstacles make them difficult to study. Normally, they inhabit the
dense African rain forests of central and western Africa, though occasionally they roam the edges of forests and so overlap the
territories of the Savanna elephants and breed with them. In 1979, Iain Douglas-Hamilton estimated the continental population of African elephants at around 1.3 million
animals.[15] This estimate is controversial and is
believed to be a gross overestimate,[16] but it is very
widely cited and has become a de facto baseline that continues to be incorrectly used to quantify downward population
trends in the species. Through the 1980s, Loxodonta received worldwide attention due to the dwindling numbers of major
populations in East Africa, largely as a result of poaching. Today, according to IUCN’s African Elephant Status Report 2007[17] there are approximately between 470,000 and 690,000 African elephants in the wild. Although this
estimate only covers about half of the total elephant range, experts do not believe the true figure to be much higher, as it is
unlikely that large populations remain to be discovered.[18] By far the largest populations are now found in Southern and Eastern Africa, which together account
for the majority of the continental population. According to a recent analysis by IUCN experts, most major populations in Eastern
and Southern Africa are stable or have been steadily increasing since the mid-1990s, at an average rate of 4.5% per
annum.[19][20]
Elephant populations in West Africa, on the other hand, are generally small and fragmented, and only account for a small
proportion of the continental total.[21] Much uncertainty
remains as to the size of the elephant population in Central Africa, where the prevalence of forest makes population surveys
difficult, but poaching for ivory and bushmeat is believed to be intense through much of the region.[22]
Asian Elephant
-
An Asian elephant swimming.
The Asian elephant is smaller than the African. It has smaller ears, and typically, only the males have large external
tusks.
"O Elephante" - Hand-coloured engraving drawn by H.Gobin and engraved by Ramus - Printed in France by the "Lamoureaux de
Paris" and Published for Magalhães e Moniz Editores in Portugal - 1890 (
From the Dr. Nuno Carvalho de Sousa Private
Collections - Lisbon)
The world population of Asian elephants – also called Indian Elephants or Elephas maximus – is estimated to be around
60,000, about a tenth of the number of African elephants. More precisely, it is estimated that there are between 38,000 and
53,000 wild elephants and between 14,500 and 15,300 domesticated elephants in Asia with perhaps another 1,000 scattered around
zoos in the rest of the world.[23] The Asian elephants'
decline has possibly been more gradual with the causes primarily being poaching and habitat destruction by human
encroachment.
There are several subspecies of Elephas maximus and some have been identified only using molecular markers. The first
subspecies is the Sri Lankan Elephant (Elephas maximus maximus). Found only
on the island of Sri Lanka, it is the largest of the Asians. There are only an estimated
3,000–4,500 members of this subspecies left today in the wild, although no accurate census has been carried out in the recent
past. Large males can weigh upward to 5,400 kg (12,000 lb) and stand over 3.4 m (11 ft) tall. Sri Lankan
males have very large cranial bulges, and both sexes have more areas of depigmentation than are found in the other Asians.
Typically, their ears, face, trunk, and belly have large concentrations of pink-speckled skin. There is an orphanage for elephants in Pinnawala Sri
Lanka, which gives shelter to disabled, injured elephants. This program plays a large role in protecting the Sri Lankan
Elephant from extinction.
Another subspecies, the Indian Elephant (Elephas maximus indicus) makes up the
bulk of the Asian elephant population. Numbering approximately 36,000, these elephants are lighter grey in colour, with
depigmentation only on the ears and trunk. Large males will ordinarily weigh only about 5,000 kg (11,000 lb) but are as
tall as the Sri Lankan. The mainland Asian can be found in 11 Asian countries, from India to Indonesia. They prefer forested
areas and transitional zones, between forests and grasslands, where greater food variety is available.
The smallest of all the elephants is the Sumatran Elephant (Elephas maximus
sumatranus). Population estimates for this group range from 2,100 to 3,000 individuals. It is very light grey and has less
depigmentation than the other Asians, with pink spots only on the ears. Mature Sumatrans will usually only measure 1.7–2.6 m
(5.6–8.5 ft) at the shoulder and weigh less than 3,000 kg (6,600 lb). An enormous animal nonetheless, it is
considerably smaller than its other Asian (and African) cousins and exists only on the island of Sumatra, usually in forested
regions and partially wooded habitats.
In 2003 a further subspecies was identified on Borneo. Named the Borneo pygmy elephant, it is smaller and tamer than other Asian elephants. It also has relatively larger
ears, longer tail and straighter tusks.
Body characteristics
Trunk
The proboscis, or trunk, is a fusion of the nose and upper lip, elongated and specialized
to become the elephant's most important and versatile appendage. African elephants are equipped with two fingerlike projections
at the tip of their trunk, while Asians have only one. According to biologists, the elephant's trunk may have over forty thousand
individual muscles in it,[24] making it sensitive enough
to pick up a single blade of grass, yet strong enough to rip the branches off a tree. Some sources indicate that the correct
number of muscles in an elephant's trunk is closer to one hundred thousand.[25]
Most herbivores (plant eaters, like the elephant) possess teeth adapted for cutting and
tearing off plant materials. However, except for the very young or infirm, elephants always use their trunks to tear up their
food and then place it in their mouth. They will graze on grass or reach up into trees to grasp leaves, fruit, or entire
branches. If the desired food item is too high up, the elephant will wrap its trunk around the tree or branch and shake its food
loose or sometimes simply knock the tree down altogether.
The trunk is also used for drinking. Elephants suck water up into the trunk (up to fifteen quarts or fourteen litres at a
time) and then blow it into their mouth. Elephants also inhale water to spray on their body during bathing. On top of this watery
coating, the animal will then spray dirt and mud, which act as a protective sunscreen. When swimming, the trunk makes an
excellent snorkel.
This appendage also plays a key role in many social interactions. Familiar elephants will greet each other by entwining their
trunks, much like a handshake. They also use them while play-wrestling, caressing during courtship and mother / child
interactions, and for dominance displays – a raised trunk can be a warning or threat, while a lowered trunk can be a sign of
submission. Elephants can defend themselves very well by flailing their trunk at unwanted intruders or by grasping and flinging
them.
An elephant can use its trunk for a variety of purposes. This one is wiping its eye.
An elephant also relies on its trunk for its highly developed sense of smell. Raising the trunk up in the air and swivelling
it from side to side, like a periscope, it can determine the location of friends, enemies, and food sources.
Tusks
The tusks of an elephant are its second upper incisors. Tusks
grow continuously; an adult male's tusks will grow about 18 cm (7 in) a year. Tusks are used to dig for water, salt,
and roots; to debark trees, to eat the bark; to dig into baobab trees to get at the pulp
inside; and to move trees and branches when clearing a path. In addition, they are used for marking trees to establish territory
and occasionally as weapons.
Like humans who are typically right- or left-handed, elephants are usually right- or
left-tusked. The dominant tusk, called the master tusk, is generally shorter and more rounded at the tip from wear. Both male and
female African elephants have large tusks that can reach over 3 m (10 ft) in length and weigh over 90 kg (200 lb).
In the Asian species, only the males have large tusks. Female Asians have tusks which are very small or absent altogether. Asian
males can have tusks as long as the much larger Africans, but they are usually much slimmer and lighter; the heaviest recorded is
39 kg (86 lb). The tusk of both species is mostly made of calcium phosphate
in the form of apatite. As a piece of living tissue, it is relatively soft (compared with other
minerals such as rock), and the tusk, also known as ivory, is strongly favoured by artists for its
carvability. The desire for elephant ivory has been one of the major factors in the reduction of the world's elephant
population.
Some extinct relatives of elephants had tusks in their lower jaws in addition to their upper jaws, such as Gomphotherium, or only in their lower jaws, such as Deinotherium.
Teeth
Elephants' teeth are very different from those of most other mammals. Over their lives they
usually have 28 teeth. These are:
Replica of an Asian Elephant's molar, showing upper side
Unlike most mammals, which grow baby teeth and then replace them with a permanent
set of adult teeth, elephants have cycles of tooth rotation throughout their entire life. After one year the tusks are permanent,
but the molars are replaced six times in an average elephant's lifetime.[26] The teeth do not emerge from the jaws vertically like with human teeth. Instead, they have a
horizontal progression, like a conveyor belt. New teeth grow in at the back of the mouth, pushing older teeth toward the front,
where they wear down with use and the remains fall out. When an elephant becomes very old, the last set of teeth is worn to
stumps, and it must rely on softer foods to chew. Very elderly elephants often spend their last years exclusively in marshy areas
where they can feed on soft wet grasses. Eventually, when the last teeth fall out, the elephant will be unable to eat and will
die of starvation. Were it not for tooth wearout, their metabolism would allow them to live much longer. Rupert Sheldrake has proposed this as an explanation for the elephant graveyards. However, as more habitat is destroyed, the elephants' living space becomes
smaller and smaller; the elderly no longer have the opportunity to roam in search of more appropriate food and will,
consequently, die of starvation at an earlier age.
Tusks in the lower jaw are also second incisors. These grew out large in Deinotherium and some mastodons, but in modern elephants they
disappear early without erupting.
Skin
Skin of an African elephant
Elephants are called pachyderms, which means thick-skinned animals. An elephant's skin is extremely tough around most
parts of its body and measures about 2.5 centimetres (1 in) thick. However, the
skin around the mouth and inside of the ear is paper thin. Normally, the skin of an Asian is covered with more hair than its
African counterpart. This is most noticeable in the young. Asian calves are usually covered with a thick coat of brownish red
fuzz. As they get older, this hair darkens and becomes more sparse, but it will always remain on their heads and tails.
The species of elephants are typically greyish in colour, but the Africans very often appear brown or reddish from wallowing
in mud holes of coloured soil. Wallowing is an important behaviour in elephant society. Not only is it important for
socialization, but the mud acts as a sunscreen, protecting their skin from harsh ultraviolet radiation. Though tough, an
elephant's skin is very sensitive. Without regular mud baths to protect it from burning, as well as from insect bites and
moisture loss, an elephant's skin would suffer serious damage. After bathing, the elephant will usually use its trunk to blow
dirt on its body to help dry and bake on its new protective coat. As elephants are limited to smaller and smaller areas, there is
less water available, and local herds will often come too close over the right to use these limited resources.
Wallowing also aids the skin in regulating body temperatures. Elephants have difficulty in releasing heat through the skin
because, in proportion to their body size, they have very little of it. The ratio of an elephant's mass to the surface area of
its skin is many times that of a human. Elephants have even been observed lifting up their legs to expose the soles of their
feet, presumably in an effort to expose more skin to the air. Since wild elephants live in very hot climates, they must have
other means of getting rid of excess heat.
Legs and feet
Elephant using its feet to crush a
watermelon prior to eating it
An elephant's legs are great straight pillars, as they must be to support its bulk. The elephant needs less muscular power to
stand because of its straight legs and large pad like feet. For this reason an elephant can stand for very long periods of time
without tiring. In fact, African elephants rarely lie down unless they are sick or wounded. Indian elephants, in contrast, lie
down frequently.
The feet of an elephant are nearly round. African elephants have three nails on each hind foot, and four on each front foot.
Indian elephants have four nails on each hind foot and five on each front foot. Beneath the bones of the foot is a tough,
gelatinous material that acts as a cushion or shock absorber. Under the elephant's weight the foot swells, but it gets smaller
when the weight is removed. An elephant can sink deep into mud, but can pull its legs out readily because its feet become smaller
when they are lifted.[citation needed]
An elephant is a good swimmer, but it can neither trot, jump, nor gallop. It does have two gaits: a walk, and a faster gait that is
similar to running. In walking the legs act as pendulums, with the hips and shoulders rising and falling while the foot is
planted on the ground. With no "aerial phase," the faster gait does not meet all the criteria of running, as elephants always
have at least one foot on the ground. However an elephant moving fast uses its legs like a running animal does, with the hips and
shoulders falling and then rising while the feet are on the ground. In this gait an elephant will have three feet off the ground
at one time. As both of the hind feet and both of the front feet are off the ground at the same time, this gait has been likened
to the hind legs and the front legs taking turns running.[27] Although they start this "run" at only 8 km/h,[28] elephants may reach 25 km/h, all the while using the same gait. At this speed most other
four-legged creatures are well into a gallop, even with leg length accounted for.
Spring-like kinetics may explain the difference between the motion of these and other animals.[29]
Ears
The large flapping ears of an elephant are also very important for temperature regulation. Elephant ears are made of a very
thin layer of skin stretched over cartilage and a rich network of blood vessels. On hot days, elephants will flap their ears
constantly, creating a slight breeze. This breeze cools the surface blood vessels, and then the cooler blood gets circulated to
the rest of the animal's body. The hot blood entering the ears can be cooled as much as ten degrees Fahrenheit before returning
to the body. Differences in the ear sizes of African and Asian elephants can be explained, in part, by their geographical
distribution. Africans originated and stayed near the equator, where it is warmer. Therefore, they have bigger ears. Asians live
farther north, in slightly cooler climates, and thus have smaller ears.
The ears are also used in certain displays of aggression and during the males' mating period. If an elephant wants to
intimidate a predator or rival, it will spread its ears out wide to make itself look more massive and imposing. During the
breeding season, males give off an odour from a gland located behind their eyes. Joyce Poole, a well-known elephant researcher,
has theorized that the males will fan their ears in an effort to help propel this "elephant cologne" great distances.
Walking at a normal pace an elephant covers about 3 to 6 km/h (2 to 4 mph) but they can reach 40 km/h (24 mph)
at full speed.
Evolution
Evolution of elephants from the ancient
Eocene (
bottom) to the modern day
(
top).
Although the fossil evidence is uncertain, scientists discovered genetic evidence that the elephant family shares distant
ancestry with the Sirenians (sea cows) and the hyraxes through
gene comparisons. In the distant past, members of the hyrax family grew to large sizes, and it seems likely that the common
ancestor of all three modern families was some kind of amphibious hyracoid. One theory suggests that these animals spent most of
their time under water, using their trunks like snorkels for breathing. Modern elephants have
retained this ability and are known to swim in that manner for up to 6 hours and 50 km.
In the past, there was a much wider variety of elephant genera, including the mammoths,
stegodons and deinotheria. There was also a much wider
variety of species.[30][31]
Diet
Elephants are herbivores, spending 16 hours a day collecting plant food. Their diet is at
least 50% grasses, supplemented with leaves, bamboo, twigs, bark, roots, and small amounts of fruits, seeds and flowers. Because
elephants only digest 40% of what they eat, they have to make up for their digestive system's lack of efficiency in volume. An
adult elephant can consume 140–270 kg (300–600 lb) of food a day. 60% of that food leaves the elephant's body
undigested.
Intelligence
With a mass just over 5 kg ((11 lb), elephant brains are larger than those of any land animal, and although the
largest whales have body masses twentyfold those of a typical elephant, whale brains are barely
twice the mass of an elephant's. A wide variety of behaviour, including those associated with grief, art, play, use of tools,[32] compassion and self-awareness [33] evidence a
highly intelligent species on par with cetaceans and primates.[34]
The largest areas in elephant brain are those responsible for hearing, smell and movement coordination, and a large portion of
the brain has to do with trunk management and sensitivity.
Senses
Elephants have well innervated trunks, and an exceptional sense of hearing and smell. The hearing receptors reside not only in
ears, but also in trunks that are sensitive to vibrations, and most significantly feet, which have special receptors for low
frequency sound and are exceptionally well innervated. It is believed that sound communication between elephants on large
distances, through the ground, is important in their social lives, and elephants are observed listening by putting trunks on the
ground and carefully moving their very sensitive feet.
Social behaviour
Elephant footprints (tire tracks for scale)
Elephants live in a structured social order. The social lives of male and female elephants are very different. The females
spend their entire lives in tightly knit family groups made up of mothers, daughters, sisters, and aunts. These groups are led by
the eldest female, or matriarch. Adult males, on the other hand, live mostly solitary lives.
The social circle of the female elephant does not end with the small family unit. In addition to encountering the local males
that live on the fringes of one or more groups, the female's life also involves interaction with other families, clans, and
subpopulations. Most immediate family groups range from five to fifteen adults, as well as a number of immature males and
females. When a group gets too big, a few of the elder daughters will break off and form their own small group. They remain very
aware of which local herds are relatives and which are not.
The life of the adult male is very different. As he gets older, he begins to spend more time at the edge of the herd,
gradually going off on his own for hours or days at a time. Eventually, days become weeks, and somewhere around the age of
fourteen, the mature male, or bull, sets out from his natal group for good. While males do live primarily solitary lives, they
will occasionally form loose associations with other males. These groups are called bachelor herds. The males spend much more
time than the females fighting for dominance with each other. Only the most dominant males will be permitted to breed with
cycling females. The less dominant ones must wait their turn. It is usually the older bulls, forty to fifty years old, that do
most of the breeding.
The dominance battles between males can look very fierce, but typically they inflict very little injury. Most of the bouts are
in the form of aggressive displays and bluffs. Ordinarily, the smaller, younger, and less confident animal will back off before
any real damage can be done. However, during the breeding season, the battles can get extremely aggressive, and the occasional
elephant is injured. During this season, known as musth, a bull will fight with almost any other
male it encounters, and it will spend most of its time hovering around the female herds, trying to find a receptive mate.
Self-awareness
Mirror self recognition is a test of self awareness and cognition used in animal studies. A mirror was provided and visible
marks were made on the elephant. The elephants investigated these marks, that were visible only via the mirror. The tests also
included non-visible marks to rule out the possibility of their using other senses to detect these marks. This shows that
elephants recognize the fact that the image in the mirror is their own self and such abilities are considered the basis for
empathy, altruism and higher social interactions. This ability had earlier only been demonstrated in humans, apes and dolphins.[35]
Homosexuality
African as well as Asiatic males will engage in same-sex bonding and mounting. Such encounters are often associated with
affectionate interactions, such as kissing, trunk intertwining, and placing trunks in each other's mouths. The encounters are
analogous to heterosexual bouts, one male often extending his trunk along the other's back and pushing forward with his tusks to
signify his intention to mount. Unlike heterosexual relations, which are always of a fleeting nature, those between males result
in a "companionship", consisting of an older individual and one or two younger, attendant males. Same-sex relations are common
and frequent in both sexes, with Asiatic elephants in captivity devoting roughly 45% of sexual encounters to same-sex
activity.[36]
Communication
Elephants communicate over long distances by producing and receiving low-frequency sound (infrasound), a sub-sonic rumbling,
which can travel through the ground farther than sound travels through the air. This can be felt by the sensitive skin of an
elephant's feet and trunk, which pick up the resonant vibrations much as the flat skin on the head of a drum. To listen
attentively, every member of the herd will lift one foreleg from the ground, and face the source of the sound, or often lay its
trunk on the ground. The lifting presumably increases the ground contact and sensitivity of the remaining legs. This ability is
thought also to aid their navigation by use of external sources of infrasound. Discovery of this new aspect of elephant social
communication and perception came with breakthroughs in audio technology, which can pick up frequencies outside the range of the
human ear. Pioneering research in elephant infrasound communication was done by Katy
Payne, of the Elephant Listening Project,[37] and
is detailed in her book Silent Thunder. Though this research is still in its infancy, it is helping to solve many
mysteries, such as how elephants can find distant potential mates, and how social groups are able to coordinate their movements
over extensive range.
Reproduction, calves, and calf rearing
Reproduction
Females (cows) reach sexual maturity at around 9–12 years of age and become pregnant for the first time, on average,
around age 13. They can reproduce until ages 55–60. Females give birth at intervals of about 5 years. Their gestation (pregnancy) period lasts about 22 months (630–660 days), the longest gestation period of any mammal,
after which typically one calf is born. Twins are rare. Labour ranges in length from 5 minutes to 60 hours. The average length of
labour is 11 hours. At birth, calves weigh around 90–115 kg (200–250 lb), and they gain 1 kg (2–2.5 lb) a
day. In the wild, the mother is accompanied by other adult females (aunts), who protect the young, and baby elephants are raised
and nurtured by the whole family group, practically from the moment of birth.
Motherhood and calf rearing
African elephant calf nursing
The first sound a newborn calf usually makes is a sneezing or snorting sound to clear its nasal passages of fluids In the first few minutes after a captive birth,
the keepers must monitor the calf closely for the first sound or movement. Whichever happens first, the mother typically responds
to her new baby with surprise and excitement. With the help of its mother, a newborn calf usually struggles to its feet within 30
minutes of birth. For support, it will often lean against its mother's legs. A newborn calf usually stands within one hour and is
strong enough to follow its mother in a slowly moving herd within a few days.
Unlike most mammals, female elephants have a single pair of mammary glands located just
behind the front legs. When born, a calf is about 90 centimeters (3 feet) high, just tall enough to reach its mother's nipples. A
calf suckles with its mouth, not its trunk, which has no muscle tone. To clear the way to
its mouth so it can suckle, the calf will flop its trunk onto its forehead. A newborn calf suckles for only a few minutes at a
time but many times per day, consuming up to 11 litres (3 U.S. gallons) of milk in a single day. A calf may nurse for up to 2
years or more. Complete weaning depends on the disposition of the mother, the amount of
available milk, and the arrival of another calf.
Newborn calves learn mainly by observing adults, not from instinct. For example, a calf
learns how to use its trunk by watching older elephants using their trunks. It takes several months for a calf to control the use
of its trunk. This can be observed as the calf trips over its trunk or as the trunk wiggles like a rubbery object when the calf
shakes its head.
Elephant calves
Elephant social life revolves around breeding and raising of the calves. A female will usually be ready to breed around the
age of thirteen, at which time she will seek out the most attractive male to mate with. Females are generally attracted to
bigger, stronger, and, most importantly, older males. Such a reproductive strategy tends to increase their offspring's chances of
survival.
After a twenty-two-month pregnancy, the mother will give birth to a calf that will weigh about 113 kg (250 lb) and
stand over 76 cm (2.5 ft) tall. Elephants have a very long childhood. They are born with fewer survival instincts than
many other animals. Instead, they must rely on their elders to teach them the things they need to know. Today, however, the
pressures humans have put on the wild elephant populations, from poaching to habitat destruction, mean that the elderly often die
at a younger age, leaving fewer teachers for the young.
All members of the tightly knit female group participate in the care and protection of the young. Since everyone in the herd
is related, there is never a shortage of baby-sitters. In fact, a new calf is usually the centre of attention for all herd
members. All the adults and most of the other young will gather around the newborn, touching and caressing it with their trunks.
The baby is born nearly blind and at first relies, almost completely, on its trunk to discover the world around it.
Allomothers
After the initial excitement, the mother will usually select several full-time baby-sitters, or "allomothers", from her group.
According to Cynthia Moss, a well known researcher, these allomothers will help in all aspects of raising the calf.[citation needed] They walk with the young as the herd
travels, helping the calves along if they fall or get stuck in the mud. The more allomothers a baby has, the more free time its
mother has to feed herself. Providing a calf with nutritious milk means the mother has to eat more nutritious food herself. So,
the more allomothers, the better the calf's chances of survival. An elephant is considered an allomother when she is not able to
have her own baby. A benefit of being an allomother is that she can gain experience or receive assistance when caring for her own
calf.
Effect on the environment
Elephants' foraging activities affect the areas in which they live:
- By pulling down trees to eat leaves, breaking branches, and pulling out roots they create clearings in which new young trees
and other vegetation grow to provide future nutrition for elephants and other organisms.
- Elephants make pathways through the environment that are used by other animals to access areas normally out of reach. The
pathways have been used by several generations of elephants, and today people are converting many of them to paved roads.
- During the dry season elephants use their tusks to dig into dry river beds to reach underground
sources of water. These newly dug water holes may become the only source of water in the area.
- Elephants are a species which many other organisms depend on. For example, termites eat
elephant feces and often begin building termite mounds under piles of elephant feces.
Threat of extinction
Hunting
The threat to the African elephant presented by the ivory trade is unique to the species. Larger, long-lived, slow-breeding
animals, like the elephant, are more susceptible to overhunting than other animals. They cannot hide, and it takes many years for
an elephant to grow and reproduce. An elephant needs an average of 140 kg (300 lb) of vegetation a day to survive. As
large predators are hunted, the local small grazer populations (the elephant's food competitors) find themselves on the rise. The
increased number of herbivores ravage the local trees, shrubs, and grasses. Elephants themselves have few natural predators
besides man and, occasionally, lions.
Dehabitation
Another threat to elephant's survival in general is the ongoing cultivation of their habitats with increasing risk of
conflicts of interest with human cohabitants. These conflicts kill 150 elephants and up to 100 people per year in Sri
Lanka.[38] Lacking the massive tusks of its African
cousins, the Asian elephant's demise can be attributed mostly to loss of its habitat.
As larger patches of forest disappear, the ecosystem is affected in profound ways. The trees are responsible for anchoring
soil and absorbing water runoff. Floods and massive erosion are common results of deforestation. Elephants need massive tracts of
land because, much like the slash-and-burn farmers, they are used to crashing through the forest, tearing down trees and shrubs
for food and then cycling back later on, when the area has regrown. As forests are reduced to small pockets, elephants become
part of the problem, quickly destroying all the vegetation in an area, eliminating all their resources.
National parks
Africa's first official reserve eventually became one of the world's most famous and successful national parks.
Kruger National Park in South Africa first became a reserve against great
opposition in 1898 (then Sabi Reserve). It was deproclaimed and reproclaimed several times before
it was renamed and granted national park status in 1926. It was to be the first of many.
There were many problems in establishing these reserves. For example, elephants range through a wide tract of land with little
regard for national borders. However, when most parks were created, the boundaries were drawn at the human-made borders of
individual countries. Once a fence was erected, many animals found themselves cut off from their winter feeding grounds or spring
breeding areas. Some animals died as a result, while some, like the elephants, just trampled through the fences. This did little
to belie their image as a crop-raiding pest. The more often an elephant wandered off its reserve, the more trouble it got into,
and the more chance it had of being shot by an angry farmer. When confined to small territories, elephants can inflict an
enormous amount of damage to the local landscapes. Today there are still many problems associated with these parks and reserves,
but there is now little question as to whether or not they are necessary. As scientists learn more about nature and the
environment, it becomes very clear that these parks may be the elephant's last hope against the rapidly changing world around
them.
Additionally, Kruger National Park has suffered from elephant overcrowding, at the expense of other species of wildlife within
the reserve. South Africa slaughtered 14,562 elephants in the reserve between 1967 and 1994; it stopped in 1995, mostly due to
international and local pressure. Without action, it is predicted that the elephant population in Kruger National Park will
triple to 34,000 by 2020.[39]
Humanity and elephants
Harvest from the wild
The harvest of elephants, both legal and illegal, has had some unexpected consequences on elephant anatomy as well. African
ivory hunters, by killing only tusked elephants, have given a much larger chance of mating to elephants with small tusks or no
tusks at all. The propagation of the absent-tusk gene has resulted in the birth of large numbers of tuskless elephants, now
approaching 30% in some populations (compare with a rate of about 1% in 1930). Tusklessness, once a very rare genetic
abnormality, has become a widespread hereditary trait.
It is possible, if unlikely, that continued selection pressure could bring about a complete absence of tusks in African
elephants, a development normally requiring thousands of years of evolution. The effect of tuskless elephants on the environment,
and on the elephants themselves, could be dramatic. Elephants use their tusks to root around in the ground for necessary
minerals, tear apart vegetation, and spar with one another for mating rights. Without tusks, elephant behaviour could change
dramatically.[40]
Domestication and use
African Savanna Elephant
Loxodonta africana, born 1969 (left), and
Asian Elephant
Elephas maximus, born 1970 (right), at an
English
zoo.
Elephants have been working animals used in various capacities by humans. Seals found
in the Indus Valley suggest that the elephant was first domesticated in ancient India. However, elephants have never been truly
domesticated: the male elephant in his periodic condition of musth is dangerous and
difficult to control. Therefore elephants used by humans have typically been female, war elephants being an exception, however:
as female elephants in battle will run from a male, only males could be used in war. It is generally more economical to capture
wild young elephants and tame them than breeding them in captivity (see also elephant
"crushing").
War elephants were used by armies in the Indian sub-continent, and later by the
Persian empire. This use was adopted by Hellenistic armies after Alexander the Great
experienced their worth against king Porus, notably in the Ptolemaic and Seleucid diadoch empires. The Carthaginian general Hannibal took elephants across the Alps when he was fighting the Romans, but brought too few elephants to be
of much military use, although his horse cavalry was quite successful; he probably used a now-extinct third African (sub)species,
the North African (Forest) elephant, smaller than its two southern cousins, and presumably easier to domesticate. A large
elephant in full charge could cause tremendous damage to infantry, and cavalry horses would be afraid of them (see
Battle of Hydaspes).
Throughout Siam, India, and most of South Asia elephants
were used in the military for heavy labour, especially for uprooting trees and moving logs, and were also commonly used as
executioners to crush the condemned underfoot.
Elephants have also been used as mounts for safari-type hunting, especially Indian
shikar (mainly on tigers), and as ceremonial mounts for royal and religious occasions, whilst Asian elephants have been
used for transport and entertainment, and are common to
circuses around the world.
African elephants have long been reputed to not be domesticable, but some entrepreneurs have succeeded by bringing Asian
mahouts from Sri Lanka to Africa. In Botswana, Uttum Corea has been working with African elephants and has several young tame elephants near
Gaborone. African elephants are more temperamental than Asian elephants, but are easier to
train. Because of their more sensitive temperaments, they require different training methods than Asian elephants and must be
trained from infancy hence Corea worked with orphaned elephants. African elephants are now being used for (photo) safaris.
Corea's elephants are also used to entertain tourists and haul logs.
Elephants are also commonly exhibited in zoos and wild animal parks, the former of which has caused controversy. Animal rights advocates allege
that elephants in zoos "suffer a life of chronic physical ailments, social deprivation, emotional starvation, and premature
death".[41] However, zoos argue that standards for
treatment of elephants are extremely high and that minimum requirements for such things as minimum space requirements, enclosure
design, nutrition, reproduction, enrichment and veterinary care are set to ensure the wellbeing of elephants in captivity.
Elephants in culture
- George Orwell wrote a famous essay entitled "Shooting an Elephant", chronicling a 1926 episode of being forced to shoot an elephant while he
served as an Imperial Policeman in Burma.
- A famous story of Ivo Andrić is titled "A Story about the Vezier's Elephant."
Popular culture
- The phrase 'elephants never forget' has no metaphorical meaning, it refers literally to elephants supposedly having an
excellent memory.
- The expression white elephant refers to an expensive burden, particularly to a
situation in which much has been invested with false expectations. The phrase 'white elephant sale' was sometimes used in
Australia as a synonym for jumble sale.
- Jumbo, a circus elephant, has entered the English language as
a synonym for "large".
