# Elephants

Elephants

African elephants

Systematics
 Subclass : Higher mammals (Eutheria) Superordinate : Afrotheria without rank: Paenungulata without rank: Tethytheria Order : Russell animals (Proboscidea) Family : Elephants
Scientific name
Elephantidae
Gray , 1821

The elephants (Elephantidae) are a family from the order of the proboscis . The family provides the largest land animals currently living and also includes the only representatives of the order group still alive today. There are three recent distinguish species: the African elephant , the largely open landscapes of Africa south of the Sahara inhabited, the domestic also in Africa, but largely on tropical rainforests limited forest elephant and the southern and southeastern Asia occurring Asian Elephant , a variety of Uses landscape spaces. All elephants are characterized by their trunk , a muscular organ that emerged from the fusion of the nose with the upper lip, and by their tusks formed from the upper incisors . Further striking features can be found in the massive build with columnar legs and the gray, not very hairy skin.

Elephants are social animals that live in family groups made up of female individuals and their offspring. You roam more or less large action areas in search of food. The size of the action areas and the extent of the migratory movements depend on local conditions such as the landscape area used and the resulting food supply. Male animals, on the other hand, either live solitary or form up in bachelor groups. The communication with each other, both within and between the different age groups, will take place in several ways. These include smells that are conveyed through feces , urine and glandular secretions , tactile contacts with the trunk, various body gestures and a rich volume of sounds. For the latter, among other things, variable grudges in the low frequency range should be emphasized.

The diet of elephants is based on plants that are ingested with the trunk. As a rule, the animals use hard components such as grass as well as softer components such as leaves and twigs. The exact composition is determined by the seasonal availability of the individual plants. Adult males come to the Musth once a year , a phase that sometimes lasts several months and is characterized by a massive increase in hormones . As a result, there is not only a constant excretion of secretions, but also increased aggressiveness towards other members of the sex. The musth is part of reproductive behavior. The sexual cycle of the female animals is extremely long and is also marked by noticeable increases in hormones. After a gestation period of almost two years, a single young animal is usually born that grows up in the family group. Young females remain here after sexual maturity, young males then leave.

The tribal history of the elephants goes back to the end of the Miocene around 7 million years ago. It began in Africa and is part of the last development phase of the proboscis. In addition to the two genera that exist today ( Loxodonta for the African elephants and Elephas for the Asian representatives), several extinct forms have also survived. The best known belong to the genera Mammuthus (mammoths) and Palaeoloxodon . These also reached areas that are not inhabited by today's species, including western and northern Eurasia . In the course of the Pleistocene, both regions went through several phases of glaciation, which resulted in the emergence of various species of elephant adapted to the cold, including the well-known woolly mammoth . Some representatives of the mammoths were the only elephants to reach North America and established their own line of development there. Most of the members of these genera died out in the transition from the Pleistocene to the Holocene around 10,000 years ago, a few dwarfed island forms survived a little longer.

Elephants played an important role in human social development and history. They were initially hunted or used as a food resource and raw material source, found their way into art and culture more than 30,000 years ago and also gained great importance in later times with the settling down and the emergence of various advanced cultures . Only the Asian elephant, as a tamed animal, was permanently in the service of humans. It initially acted as a pack and workhorse, later it was used in wars and was considered a symbol of extraordinary greatness and power.

The first scientific description of the African and Asian elephants dates back to 1758. Both species were initially assigned to a single genus, and the two representatives were generically separated only at the beginning of the 19th century. The forest elephant has only been recognized as a separate species since the early 2000s. The elephant family was introduced in 1821. The populations of the three species are considered to be endangered to different degrees.

## features

### Habitus

Comparison of the head and front of the body of Asian (1) and African (2) elephants

Elephants are the largest land animals still alive. The smallest recent representative, the forest elephant ( Loxodonta cyclotis ), reaches a body height of around 2.1 m and a weight of around 2 t, the largest form today, the African elephant ( Loxodonta africana ) is up to 3.7 m high and then weighs around 6.6 t. The largest scientifically measured specimen, an animal from Angola, had a shoulder height of 4 m and probably weighed around 10 t. The Asian elephant ( Elephas maximus ) mediates between these two forms in terms of body size and weight. In their phylogenetic past, the elephants showed a significantly greater range of variation. The smallest forms are formed by some island dwelling dwarf elephants . In some of these elephants the dwarfing effect was so strong that they were only between 2 and 7% the size of the original species. These include the Sicilian dwarf elephant ( Palaeoloxodon falconeri ) or the Crete dwarf mammoth ( Mammuthus creticus ), which were only around 1 m high and weighed between 170 and 240 kg. The largest elephants are found with Palaeoloxodon namadicus and Palaeoloxodon recki or with the steppe mammoth ( Mammuthus trogontherii ) and the prairie mammoth ( Mammuthus columbi ), whose height fluctuated between 4.2 and 4.5 m. Your body weight should have been 12 to 15 tons. In terms of size, today's species have a distinctive sexual dimorphism with significantly larger males than females.

Generally elephants are massive animals with a large and short, but high head on a short neck, columnar legs and a tail over a meter long with a brush-like end. The most noticeable feature is the trunk , a tubular muscle body that emerged from the nose, which was fused with the upper lip. The shape of the trunk means that the mouth opening of the elephants is relatively small. The upper tusks , which are mainly developed in adult animals, are a further characteristic . On the side of the head there are large, fan-like ears that vary in size depending on the species. The body is plump, the back line is either straight or saddled like the African elephant or arched like the Asian elephant. In the former, the highest point on the body is on the shoulders, in the latter on the forehead. The fur of the elephants is very sparsely developed, longer hair mostly occurs on the chin and the tip of the trunk as well as on the tail end. The skin is gray in color, but often has pigment-free areas. The actual skin color can be whitewashed by dirt and dust.

The larger front legs carry around 60% of the body weight. Fore and hind feet each end in five rays. These are not visible from the outside, but rather embedded in a pad made up of various strands and layers of fibrous connective tissue , interrupted in turn by chambers made of fatty tissue . It also contains collagen , reticulin and elastic fibers. The cushion penetrates the foot and fills the space between the individual bones. The sole of the foot consists of a uniform surface that is rounded at the front and oval at the back. On the respective front there are “nail-like” or “hoof-like” structures, the number of which is sometimes used to differentiate between species (African elephant front four, rear three; forest elephant front five, rear four; Asian elephant front five, rear four to five), in principle but is highly variable. As a rule, the side nails are reduced. The "hooves" are largely similar to the comparable formations in ungulates .

### Skull and skeletal features

#### skull

Asian elephant skull in side (left) and frontal (right) view
Skull of an elephant with visible honeycomb-like, air-filled chambers

The elephant's skull is large, tall and short. The top of the skull at the highest point bulges in part like a dome. The short skull resulted from the reduction of the snout and the forward displacement of the occiput ; the latter falls heavily forward in today's elephants. The compression of the skull in the anterior and posterior areas also causes the center of gravity to be shifted far back. An outstanding feature are the large, honeycomb- shaped, air-filled chambers that penetrate the frontal bone , parietal bone , nasal bone and the intermaxillary bone . As a result, the top of the skull can reach a thickness of up to 40 cm. The pneumatizations increase the surface of the skull enormously and thus expand the attachment surface for the massive chewing and neck muscles. At the same time, they reduce the weight of the skull. Another characteristic is the strongly receded nasal bone, which creates space for the extraordinarily large muscles of the trunk. Both traits can be found in numerous lines of proboscis. Due to the reduction of the nasal bone, the intermediate jaw is also directly connected to the frontal bone, which is a general characteristic of Tethytheria . In elephants, the intermaxillary bone frames the respective alveolus of the tusks. The tusk alveoli are more perpendicular to the skull, which means that the tusks protrude downwards, which is also due to the short skull. This forms a clear contrast to most of the earlier forms of proboscis, whose tusk fans are more clearly oriented horizontally due to the long skull. The high position of the nostril as well as the forward- facing orbita can be highlighted as further characteristics typical of elephants . The compression of the skull also resulted in changes to the skull base. The vertical position of the wing processes of the sphenoid and the downward dented palate should be mentioned here.

The elephant's lower jaw is short and high. The horizontal bony body looks massive, the ascending branch is greatly broadened. The special shape of the lower jaw means that the crown process, a bony extension of the ascending branch that serves as a muscle attachment point, lies far in front and lies roughly above the (mass) center of gravity. Together with the articular process, it rises up so that the joint connection with the skull is clearly above the occlusal plane. The symphysis , which connects the two halves of the lower jaw at the front end, is also shown briefly. Compared to more original elephant shapes, the lower jaw of today's representatives is therefore strikingly designed. In the former, it was much more elongated, had a long symphysis, to which the tooth sockets of the lower tusks connected laterally.

Many of the elephant-typical features on the skull and lower jaw can be traced back to a restructuring in the chewing apparatus, which caused the shortening in the longitudinal direction of the skull. The chewing apparatus specializes in horizontal forward and backward movements. Other earlier trunk lines used mainly laterally oriented grinding movements.

#### tusks

Prairie mammoth with the typical spiral shaped tusks of the
mammoth

Elephants have two types of teeth: the hypertrophied and rootless central incisors of the upper row of teeth (I2), which have been transformed into tusks, and the molars. Older forms such as stegotetrabelodon still had tusks in the lower jaw, which had developed from the lower inner incisors, but were lost in the course of tribal history due to cuts in the lower jaw, especially in the area of ​​the symphysis , a process that can be traced in several lines within the proboscis can. Today's elephants mainly use their tusks for digging, for debarking trees, for carrying heavy objects and as a weapon against competitors or for showing off. The tusks grow permanently and throughout life. They can be trained in both sexes, for example in the African elephant or in the various mammoths, or mainly in male animals, for example in the Asian elephant. As a rule, they are curved upwards and outwards or shaped spirally. Today's species can have tusks up to 345 cm in length, sometimes weighing over 110 kg, with the African elephant having larger tusks on average than the Asian elephant. The longest known tusks, however, were formed in the various mammoths - record dimensions are 490 cm. Usually about a quarter of the length of the tusks is in the alveoli. Young animals have milk tusks, so-called “ tushes ”, which fall out in the first year of life and are replaced by the permanent teeth.

The tusks, commonly called ivory , are made of carbonate - hydroxyapatite crystals (main component dahllite ), which are connected with collagen fibers . The former mainly contribute to the hardness of the tusks, while the latter ensure elasticity. Structurally, the tusks consist of three zones. The main component is the dentin , which is similar to the bone substance, but is highly mineralized and therefore free of cells . It has a fibrous structure and is interspersed with numerous tubules filled with collagen. The mineral share is around 59%, the organic around 33%, the rest is water. The dentin is covered with a thin layer of dental cement . Inside, the pulp , the main growth zone , expands . The resulting new tooth material is deposited in multiple growth spurts, the length of which varies between a few millimeters up to 35 cm. On average, an annual growth rate of around 17 cm can be expected. Due to the growth spurts, the tusk is made up of numerous conical "hats" placed one on top of the other . In cross-section, these growth phases appear as ring-like with the oldest zones on the outside and the youngest on the inside, comparable to the tree rings in reverse order. Large amounts of calcium and sodium are required for the formation of the dentin . which in the Asian elephant amount to about 60 g of calcium and 100 g of sodium per day. Tooth enamel is usually not formed on the tusks of elephants, it is only found at the tip, but is abraded relatively quickly by using the teeth. In contrast, the milk tusks still have a thin layer of enamel. The lack of tooth enamel distinguishes the elephants from older trunk lines.

“Schreger lines” in the cross section of a tusk

The dentin of the tusks has a conspicuous complex formation, which are known as "Schreger lines" and occur only in elephants. These are alternately light and dark colored areas that form a checkerboard pattern in the tooth cross section. It is composed of rhombic , alternating light or dark colored surfaces, which on the one hand run radially from the outer tooth cement to the inner pulp and on the other hand tangentially along the tooth cement. The size and shape of the surfaces vary depending on the position in the tooth cross-section with smaller rhombuses on the inside, larger ones on the outside and more square structures in the central area. The size of the individual areas ranges from 200 to 800 μm². The changing expansion of the surfaces creates the optical illusion of a spiral pattern with intersecting lines in the tooth cross-section. The angle at which the lines meet is called the "Schreger angle" and can be used to determine the species (African elephants 118 ( L. africana ) to 123 ° ( L. cyclotis ), Asian elephant 112 °, woolly mammoth 87 °, European forest elephant 130 °). In the longitudinal direction of the tusk, the "Schreger lines" appear as a band pattern of light and dark areas with a thickness of around 500 μm. The origin of the pattern is controversial. Some researchers believe that the "Schreger lines" arise from the arrangement of the dentin tubules, which in turn originate from the migration of odontoblasts during tusk growth and dentin formation. Other authors derive the pattern from the special orientation of the collagen fibers.

#### Rear dentition and change of teeth

Elephant molars.
Above: African elephant.
Middle: Asian elephant.
Below: †  woolly mammoth ;
The number and thickness of the enamel lamellae provide information about eating habits
Enamel lamellae of an elephant's tooth, here a mammoth, in detail
View of the palate of the skull of a poached African elephant without tusks, the left is in front. At the time of death there were four molars in the jaw, the front teeth in function along the entire length. At the front end of the two rear molars that have not yet fully erupted, the first signs of wear can be seen.

The distinguishing feature of the rear teeth is their structure from individual lamellae , which is accordingly referred to as lamellodont . The individual lamellae are made of tooth enamel and are embedded in a matrix of dental cement. Depending on the type, the teeth differ in the number and course of the enamel lamellae, so they have taxonomic value. A differentiating criterion is the lamella frequency, which results from the number of enamel lamellae per ten centimeter tooth length. The assessment is usually based on the third molar, which is the largest and therefore has the highest number of enamel folds. It can weigh up to 5 kg and has up to 13 enamel lamellae in the African elephant and up to 24 in the Asian elephant. The extinct woolly mammoth ( Mammuthus primigenius ) was the most specialized elephant species and had molar teeth with up to 30 enamel lamellae. In general, the number of enamel lamellae within the individual development lines (genus) of the elephants increases. This goes hand in hand with a thinning of the tooth enamel, so that phylogenetically younger forms have largely narrower and narrower lamellae than older ones. The increase in enamel lamellae per tooth directly reflects the animals' changing diets. In order to withstand the strong abrasive forces of chewing with the thinning enamel, it formed extremely tight folds and coils on the one hand, and on the other hand the tooth crowns were raised. Today's elephants have high-crowned ( hypsodontic ) molars (that is, the tooth height exceeds the tooth width), while more original forms often had low-crowned ( brachyodontic ) teeth.

There is a toothless area between the tusks and the molars, commonly known as the diastema . Such a diastema is typical of the teeth of herbivorous mammals. Viewed over its entire life, an elephant has six molars per half of the jaw: three premolars (premolars dP2 to dP4 or dp2 to dp4) and three molars (molars M1 to M3 or m1 to m3), with the premolars corresponding to the deciduous molars , which Molars have the permanent back molars, which are also common in other mammals. So there are a total of 24 molars. The dental formula including the tusks indicated generally as follows: . In general, the dentition of today's adult elephants no longer has permanent premolars, in some early forms such as stegotetrabelodon , primelephas and in original representatives of the genus Loxodonta a permanent last premolar was found. This tooth, which is usually small in the more primitive elephants, was much more common in older lines of the proboscis and was lost several times independently of each other in the course of the tribal history, mostly in connection with the reduction in the lower tusks and the associated decrease in length of the mandibular symphysis. ${\ displaystyle {\ frac {1.0.3.3.} {0.0.3.3.}}}$

Since the elephant's jaws are relatively short and the molars comparatively large, one half of the jaw always only has one to three molars at a time, but only part of it is broken through, i.e. only visible. The chewing surface is always only formed by the molar or molars that are close to the diastema (i.e. in the front area of ​​the jaw). Adult elephants have a maximum of one and a half molars per branch of the jaw in function at the same time. When chewing or grinding the relatively hard plant food, the teeth wear out a lot. To ensure that the grinding performance always remains the same, “fresh” tooth material moves continuously from the rear end of the jaw, like on a very slow conveyor belt, to the diastema. This migration is made possible by the resorption and rebuilding of jawbone substance. In the heavily worn parts of the teeth directly on the diastema, the roots are resorbed, so that they die off, no longer have a hold in the jaw and finally break off. After the first three molars of the youth stage have fallen out, the fourth erupts completely at the age of about 10 to 14 years, that of the fifth at 26 to 27 years and the sixth and last at 34 to 37 years (each based on the age of one African elephants). If an elephant has worn out all of its 24 molar teeth while it is still alive, it will starve to death. This special form of renewal of tooth substance is called horizontal tooth change and occurs today almost without exception in elephants. It developed very early in phylloxera within the proboscis and was first detected in the Eritrean genus in the Upper Oligocene around 27 million years ago.

The horizontal change of teeth leads to cyclical changes in body weight in the elephants. This is caused by pushing in a new tooth, which is then available as an additional chewing surface. This allows an animal to take in more food or chew it more intensively. The fluctuations in body weight are up to 300 kg, but they are only noticeable in zoo animals with a regular and even food supply. Elephants living in the wild are subject to a seasonal, qualitatively and quantitatively differing food supply, which may override this effect.

#### Body skeleton

Skeletal reconstruction of the woolly mammoth
Skeletal reconstruction of the Asian elephant

The elephant skeleton consists of 320 to 346 individual bones. In an Asian elephant that was examined, it weighed 374 kg when fresh and made up about 15% of the body mass. The spine consists of 7 cervical, 18 to 21 thoracic, 3 to 5 lumbar, 3 to 6 sacrum and 18 to 34 caudal vertebrae. The number of vertebrae and also of the ribs (18 to 21 pairs) varies depending on the species. The long bones lack the typical medullary cavity , instead the inside is filled with cancellous material. The same goes for the ribs. On the front legs, the humerus is extremely strong and its joint head is only indistinctly off the shaft. The ulna dominates the forearm and is about five times as heavy as the radius . Both bones are not fused together. The pelvis is shaped by the extremely large and expansive shovel of the iliac bone . The thigh bone represents the longest bone in the skeleton. It can be up to 127 cm long in an African elephant, in individual extinct forms such as some representatives of the genera Mammuthus and Palaeoloxodon it was 140 to 165 cm long. The joint head is typically clearly rounded, a third roll hillock (trochanter tertius) is missing and is only formed as a weak point below the large roll hillock (trochanter greater) on the anterior upper shaft. The knee joint shows an extended resting position, so that the angle between the thigh and shin is almost 180 ° when standing . This is unusual for quadruped terrestrial vertebrates and is only found in two-legged humans. The elephant's thigh joint is very similar to that of humans. The menisci are very narrow and thin and the cruciate ligament system is also present. The movement patterns of the weight-bearing rear limbs are also more reminiscent of humans than of cursorial (fast-moving) land vertebrates. The main movement of the knee joint is extension - flexion with a radius of action of 142 °. In old age, the knee joints are prone to osteoarthritis . As on the forearm, the tibia and fibula are not fused on the lower leg .

The forefoot (left) and rear foot (right) of the woolly mammoth, the five-pointed structure and the serial arrangement of the root bones are visible

The front and rear bones of the foot are arranged as an arch, the bones are largely vertical. This is to be regarded as an adaptation to the extreme weight of the animals, as it reduces the resistance in the area of ​​the ankle when walking. Accordingly, from an anatomical point of view , the elephants can be viewed as tiptoe . Functionally they provide plantigrades is because, the aforementioned foot pad developed by the solid sole to compensate for the heavy weight that weighs on tiptoe. Typically for the Tethytheria , both the carpal and the tarsal bones are arranged in series, that is, the individual bones are in a row one behind the other and not alternately to one another. This structure is known as the taxeopod , a trait that the proboscis commonly share with the snakes and manatees . On the forefoot only the three middle rays (II to IV) have three phalanges each, the inner (I) has one, the outer (V) two. Of the five existing rays on the hind foot, the second to fifth each have toe phalanx; the innermost ray consists only of the metatarsal bone . However, three phalanges only appear on the third and fourth ray, otherwise there are two. In general, the number of phalanges is very variable in today's elephants. The phalanges are usually short and wide, their size decreases rapidly from the first to the third. The extremely small terminal phalanx, if any, usually does not articulate directly with the middle one. To support the elephants, a sixth beam has formed in addition to the five regular rays, which lies on the inside and precedes the thumb or the big toe. Accordingly, it is referred to as prepollex ("fore-thumb") on the front feet and prehallux ("fore-toe") on the rear foot. Both structures arise in the individual development from cartilaginous sesame bones and ossify over time. The formation can be associated with the restructuring of the forefoot and hindfoot in the course of the tribal history of the proboscis, when the tiptoe developed from the sole of the more primitive forerunners.

### Soft tissues and internal organs

#### Trunk

Head of the African elephant with the typical trunk
Trunks of various elephant species. Left: African elephant, middle: Asian elephant, right: woolly mammoth

The trunk is one of the most striking anatomical features of the elephant. It represents an agglomeration of the nose with the upper lip, which already merge in the fetal age . Externally, it forms a muscular tube without a bony substructure, which is traversed by the nasal passages. At the lower end of the "tube" these emerge through the nostrils. The filling volume of an Asian elephant with a trunk that is around 1.8 m long is around 2.2 to 3.1 l. The nostrils are surrounded by a wide, flat surface with “finger-shaped” protuberances on the edges. With the African elephant these are two opposing "fingers" on the upper and lower edge, with the Asian elephant only one on the upper edge. The woolly mammoth also had only one "finger" on the upper edge, but had a broad, shovel-shaped tip opposite. The protuberances serve primarily as a gripping organ. In principle, the trunk consists of skin, hair and muscles as well as blood and lymph vessels or nerves and a small amount of fat . Cartilage tissue is only formed at the base of the nose. As a highly sensitive organ, the trunk is traversed by two nerves, the facial nerve and the trigeminal nerve . The muscles have a supportive effect. There are two types of muscles that run lengthways on the one hand, and crosswise or diagonally on the other. It was sometimes assumed that 40,000 to 60,000 muscles intertwined in bundles move the trunk, while extrapolations on a dissected animal resulted in up to 150,000 muscle bundles. The main muscle groups include the anterior levators proboscidis , which attach to the frontal bone, run through the entire trunk and raise it. The depressores proboscidis are also important . These occupy the lower part of the trunk and are strongly connected to the transverse muscles and the skin. The trunk of the African elephant seems to have more ring-like transverse muscles, so that it appears more flexible and “lobed” than the Asian elephant.

The trunk evolved very early in the tribal history of the trunk animals. The development of the trunk led to some anatomical changes in the skull area, which are mainly due to the development of the massive muscles. The most striking is an extraordinary reduction of the nasal bone and a greatly enlarged nasal opening. Secondarily, the anterior dentition also regressed. Since the trunk bridges the distance from the head to the ground that the short neck cannot manage, the former is essential for feeding. The incisors, which in numerous mammals are mainly used in a cutting manner when eating, therefore no longer had a primary function in the proboscis. With the exception of the tusks, they therefore regressed. In addition, the trunk is a multifunctional organ that serves as a tactile and gripping organ, for breathing or smell perception as well as a weapon and threat, and also as a suction and pressure pump when drinking. Due to the whiskers located at its lower end, it is also suitable as a tactile organ with which the animals can perceive the smallest bumps. It is also used to make contact with fellow members of the herd, for example in the complex greeting rituals and when playing. With the trunk, dust and dirt are distributed on the skin, which is done to protect against strong sunlight and insects. The trunk is also used to grasp objects, for example to bring them to the mouth. With its help, an animal can reach branches and plants from a height of up to seven meters. Similar to a giraffe neck, it doubles its stretching height. Occasionally the trunk serves as a kind of snorkel when bathing or swimming, and is held high in the air to smell it. Trained working elephants can manipulate, lift and move objects of considerable weight with the help of their trunk and the support of their tusks and in cooperation with the elephant handler.

#### Skin and ears

African elephant skin with clearly visible furrows and crevices in the upper layer; Different skin layers are shown, at the bottom right an example of an Asian elephant

The skin of an Asian elephant examined weighed a total of 211 kg and covered an area of ​​11.96 m². The weight of the skin therefore corresponded to about 9.8% of the individual body weight. In comparison, the skin surface of the African elephant can be up to 26 m². The skin is sometimes very thick, up to 30 mm in the Asian elephant and up to 40 mm in the African elephant. Characteristic are a thick horny layer, various skin folds and the absence of sweat and sebum glands . The thermoregulation therefore takes place via evaporation water on the skin surface and by waving the ears. Individual measures are water and mud baths. In addition to the folds of the skin in the African elephant, it is heavily ornamented with deep furrows. The furrows and cracks arise in the uppermost layers of the epidermis (stratum corneum), which in adult individuals has only a few flakes of skin and is severely horny, which causes it to break open when subjected to bending. The water that penetrates into the cracks can be stored there five to ten times as long as that directly on the surface and thus helps regulate body temperature.

The African and Asian elephants differ in ear size. With the latter, they are around 60 cm wide and 55 cm high and cover an area of ​​0.5 m² (both sides in total). The former have ears up to 137 cm high and 89 cm wide. They take up up to 20% of the total skin surface. Another difference is the folding of the ears, which in the Asian elephant affects the upper section, whereas in the African elephant it affects the side. The ears of the woolly mammoth are significantly smaller than those of the Asian elephant. With regard to the ear size, an adaptation to the geographical latitude can be seen, which in the case of the African elephant includes the equatorial region, in the case of the woolly mammoth, on the other hand, the largely high arctic landscapes. The ears consist of a layer of skin on both sides, between which there is a layer of cartilage tissue .

#### Temporal gland

Swollen right temporal gland with secretion

Another distinctive and unique feature is the temporal gland ("temple gland") on the side of the eye, which in male animals secretes an oily secretion during the musth . The gland is also passed down from fossil forms such as the woolly mammoth. It becomes 13 to 14 cm long and is flat, its weight is about 0.23 to 1.59 kg. Inside, it consists of various flap-like structures that are connected to each other with connective tissue and enclose a cavity around 5 cm in diameter. The hollow body leads to the surface of the skin through an opening that is only 2 cm wide. It is surrounded by rod-shaped or tubular cells and various lumens . During the pronounced musth, the lumens are filled with loose cell material, free cell nuclei and mitochondria . The latter have a structure typical of steroid-producing cells (with a comb-like inner membrane) such as Leydig intermediate cells . Together with the smooth endoplasmic reticulum and the Golgi bodies, these are important for testosterone production. Numerous microvilli and secretory vacuoles are embedded in the cells around the hollow body .

During testosterone production, the cells hypertrophy. Both their number and the proportion of the mitochondrial inner membrane, smooth endoplasmic reticulum, and Golgi bodies increase. At the climax, the cell structures break down and fill the lumens. The temporal gland apparently has its origin in sweat glands with an apocrine secretion mechanism. Today's elephant species differ in the chemical composition of the secretion produced. In the African elephant, for example, the proportion of proteins , sodium or acid phosphatase is significantly lower than in the Asian elephant.

#### Internal organs

The internal organs of elephants are proportionally no larger than those of other mammals . The brain of today's elephants has 257 billion nerve cells , which is roughly 3 times the amount of humans. At around 98%, the majority of it is distributed in the cerebellum . This extraordinary concentration is attributed to the tactile abilities of the animals. In the cerebral cortex , which is about twice as large as in humans, there are only 5.6 billion nerve cells. Here humans have about three times as many cells, which in turn is related to their cognitive abilities. Overall, the brain of a fully grown elephant has a volume between 2900 and 5140 cm³, which is three times that of humans. In relation to body weight, the brain of elephants is smaller than that of humans and great apes , the encephalization quotient of today's elephants is around 1.7, and that of humans 7.5. Newborns are already 35% the size of an adult animal's brain. In some extinct forms, the brain reached a volume of over 6,000 up to 9,000 cm³, for example in the European forest elephant . The discovery of a fossilized brain of a woolly mammoth had a reconstructed volume of 4100 cm³. Its construction largely corresponded to that of today's elephants. It is noteworthy that some dwarf forms had brains that were unusually large for body weight. The Sicilian dwarf elephant weighed only around 189 kg, but its brain reached a volume of 1800 cm³. This increases the encephalization quotient to up to 3.75.

The heart weighs between 12 and 27 kg, 45 to 57 cm in length and 32 to 48 cm in width. It has a two-part pointed end, similar to what has been observed in manatees . Furthermore, a paired vena cava occurs. Both features are considered to be relatively original. It beats 28 to 35 times per minute when at rest, which is less than a human's. The stomach holds around 77 l and the intestinal tract over 610 l. The total length of the intestinal tract is around 18 to 35 m, of which the small intestine takes up the largest part with up to 22 m. The large intestine can reach up to 14 m in length. The appendix is large and baggy in shape, as is the anterior end of the colon. There is a fold in the center of the appendix which may suggest that it originally consisted of two chambers. The urinary bladder has a capacity of around 18 liters. The liver has a simple structure and is divided into two chambers of different sizes. A gallbladder is not or only rudimentary. The two wings of the lungs weigh around 98 kg and are each 1 m long and 1.2 m wide. As a special feature it can be pointed out that, in contrast to most other mammals, the lungs are directly connected to the chest cavity. There is therefore no pleural space, as the space is bridged by loose connective tissue . As a result, the pleural leaves can still be moved relative to one another, but by far not as sensitive. This enables elephants, for example, to cross a river and "snorkel" with their long trunks. The animals breathe in air at atmospheric pressure while their bodies, and thus their lungs in particular, are about 2 m under water. In any other mammal (with a “normal” pleural gap), this pressure difference would literally “squeeze out” and destroy the blood vessels that supply the wall sheet of the pleura.

The testes of the male animals are 17 cm long and 15 cm wide, and their weight varies between 1.36 and 3.18 kg. They are located in the abdominal cavity between and slightly behind the kidneys . The penis is well developed and muscular, it weighs around 49 kg with a length of 100 cm and a diameter of 15 cm. A penile foreskin is well developed, the urethra exit has a Y-like shape with the bifurcation pointing towards the back. The levator penis muscle is doubled, both strands unite on the back on the corpus cavernosum penis and are probably responsible for the fact that the penis has an S-shaped course with the tip upwards when erect. This is helpful in inserting the penis during the mating act into the vulva of the female animals on the belly side, between the hind legs . The significant forward displacement of the vulva in the female animal between the hind legs is due to the greatly elongated urogenital tract , which is up to 130 cm long and about half the length of the entire genital tract. The opening of the vulva is elongated between the legs. The clitoris has a foreskin and is about 50 cm long. The uterus of the female animals is two-horned, the horns extend long, while the uterus body remains relatively short at around 15 cm in length. The folded cervix is also around 15 cm long and has a strikingly conical shape. In contrast to most other mammals, the udders of the elephant cows are located between the forelimbs, as in the primates and manatees.

### cytology

Both the African and the Asian elephant have a chromosome set of 2n = 56. In the African elephant, the diploid karyotype consists of 25 acrocentric / telocentric pairs and two metacentric / submetacentric pairs. In contrast, the Asian elephant has one less acrocentric pair and one more submetacentric pair. In both species, the X chromosome is large and submetacentric, the Y chromosome small and acrocentric. The differences are that in the Asian elephant the corresponding male sex chromosome is slightly larger and has more distinct G-bands than in the African elephant.

## distribution

Distribution of today's elephants

Elephants are common in Asia and Africa today . The natural occurrence of the Asian elephant used to extend from the east to the south-east to the south of Asia, possibly also continuously to the western part of the continent. Today it is highly fragmented and is limited to the Indian subcontinent and to individual parts of rear India , to Sri Lanka and some of the large Sunda Islands or the southernmost area of China . The animals inhabit more open landscapes as well as more wooded areas. The African elephant once inhabited almost the entire African continent, today it also occurs in heavily fragmented habitats south of the Sahara . The northern limit of distribution is in the south of Sudan . From here the habitat extends over East and West Africa to South Africa . It inhabits a wide variety of different habitats such as savannahs , tropical rainforests, and desert-like areas. The forest elephant , in turn, lives in the rainforests of West and Central Africa .

In their phylogenetic past, the elephants were generally much more widespread and were not only found in their current core areas, but also over large parts of northern Eurasia . Most species, however, can only be found in fossil form in certain regions and thus remained locally restricted, some dwarf forms only lived endemically on individual islands . However, some representatives also achieved a very wide distribution, such as the European forest elephant ( Palaoloxodon antiquus ), which appeared in western Eurasia, or the steppe mammoth ( Mammuthus trogontherii ), which had developed different habitats from western Europe to eastern Asia . Some members of the mammoths ( Mammuthus ) also penetrated via the Bering Strait into North America and thus had a Pan-Eurasian and North American distribution. The woolly mammoth ( Mammuthus primigenius ) should be mentioned here, which mainly populated the open steppe landscapes , the so-called mammoth steppe , during the last glacial period.

## Way of life

### Territorial and social behavior

#### General

Swimming African elephant in Namibia
African elephant in the dust bath

The way of life of today's elephants is comparatively well researched. They have a circadian way of life . Activities take place both during the day and at night. The animals spend most of their time eating, which can make up around two thirds to three quarters of their active phase. Sleep typically only lasts a few hours and often occurs late at night or around noon. During this time the animals mostly stand, a REM phase is rarely reached.

Elephants usually move in the passageway so that at least two legs are always touching the ground. The average speed is then around 1.4 km / h. In general, the animals can also reach very high speeds, which are around 14 to 24 km / h. Due to their size and enormous weight, elephants do not run, which means that there is no jumping phase in which all four legs are lifted off the ground at the same time. The pass gait is largely retained and there is no transition to another form of locomotion typical for higher speeds (trot or gallop). Comparable to other four-footed animals, the clock frequency of the leg movements and the stride length increase at a higher speed, but usually one leg always remains in contact with the ground. Investigations into the movement patterns of elephants at higher speeds showed that the front legs tend to move while walking, while the rear legs tend to run. All four legs perform the same function, which means that, unlike other quadruped mammals, there is no division into propelling and decelerating limbs even at higher speeds. However, in agreement with other mammals, the work of the front legs is higher than that of the hind legs, which corresponds to the general weight distribution.

In contrast, elephants are very good swimmers who move through the water with tumbling movements similar to bottlenose dolphins. You move at about 2.7 km / h. The trunk is held above the surface of the water as a snorkel. According to observations, the animals overcome distances of up to 48 km across the open water surface. It is therefore plausible that this ability to swim enabled the elephants to reach more remote islands in the geological past and then to develop various dwarf forms. However, the reasons for this can only be speculated. It is assumed that the animals smelled the scent of food from islands in visual contact and then targeted them.

#### Social structure and use of space

Asian elephant family group in Kui Buri National Park in Thailand
Bachelor group of African elephants in Tsavo East National Park in Kenya

Elephants are generally sociable animals that live in complex social communities. But there are differences between male and female animals. Cows form social associations with the calves. The closest bond is between the mother and her offspring. In addition, different levels of group formation can be distinguished. In the case of the African elephant, these comprise, as a lower unit, family groups or herds that combine several mother-young animal groups. These can in turn join together to form larger family associations and ultimately to form clans as the highest unit. As a rule, the individuals in such groups are more closely related. The family groups or herds are led by a lead cow, who is usually an older and more experienced individual. Their role is not only important in leading the family group, it also instills important behaviors in the calves. The hierarchy within the herd is organized in a linear fashion, so that when the lead cow dies, the eldest daughter takes over its role. Herds therefore represent the stable unit within the social structure of the African elephant. With the Asian elephant, however, there are various closer or further individual ties within the family groups. A lead cow does not have the dominant role here. In both the African and the Asian elephant, the higher social units come together and break up again in loose succession, which is generally referred to as a fission-fusion social structure (“separating and coming back together”). Bulls, on the other hand, live solitary with all elephant species or organize themselves in bachelor groups, which in turn consist of individuals of different ages.

The various groups of elephants use action spaces , the size of which generally depends on the food supply in the region concerned. They are smaller, the more humid and rich in vegetation the environment is. In forested areas they often only cover a few dozen to hundreds of square kilometers, but in desert-like landscapes they extend to over ten thousand square kilometers. Most of the time, the action spaces include different types of landscape, each of which is visited as required. The elephant groups wander around in their action areas in search of food sources. The distances covered are usually short, often only a few kilometers a day. However, migration behavior can be strongly influenced by external circumstances, such as the presence of human settlements and areas of use. Over the course of the year, however, elephants cover distances of several thousand kilometers. So-called elephant roads, which can exist for a long time and are sometimes used by other animal species, then form on paths that are often used.

#### Communication and cognitive skills

The trunk as an important means of communication, here with the Asian elephant in Kaudulla National Park in Sri Lanka

Coexistence within the group and between the individual family groups is usually peaceful and cooperative. The communication with each other passes through various optical signals, tactile and chemical stimuli and vocalizations. Important elements for visual communication are the trunk and ears as well as varying head and body positions, often in different combinations. For example, a head held high or low expresses dominant or submissive behavior. Fights resulting from conflict situations are highly ritualized, exceptions are bulls in musth , in which fights can sometimes be life-threatening. The trunk also plays a central role in tactile communication, for example in the complex greeting ritual of related family groups. Chemical communication includes urine and fecal marks as well as the secretions of the temporal and inter- toe glands . It is sometimes very targeted, as the pheromones contained sometimes only have a stimulating effect on sexually active individuals. On the other hand, the members of a family group differentiate several dozen closely and distant related animals and alien organisms on the basis of their smell.

Comparison of the spectrograms of social resentment in female (left) and male (right) African elephants
African elephant nasal rumble
Oral growl of the African elephant

The elephants use a very extensive sound communication, which, however, has been studied far better in the African elephant than in the Asian. Much of the communication takes place in the infrasound area . These vibrations, which are inaudible to humans, are transmitted through the air and the ground over several kilometers and are not very susceptible to interference, for example through reflection or absorption . In addition, they work both in open terrain and in dense forests. A social rumbling with a frequency range of 10 to 200  Hz is characteristic. This is used in a wide variety of situations, but mostly serves for contact within and outside the family group. The sounds vary individually so that the animals can distinguish one another. The social rumble can be generated both through the trunk (nasal) and through the larynx (oral). Both sounds differ in the length of the generation path, which is at least twice as long in the case of nasal rumbling. They therefore have different frequencies and are used differently by animals. Nasal rumble is common when seeking contact, but oral rumbling is heard within the family group. In addition to these sounds in the low frequency range, there are also higher frequencies, some of which can reach up to 9000 Hz. These include a wide variety of noises, from the familiar trumpet to barking, roaring or screaming to snorting or croaking. Their reproduction depends on various factors, they often act as alarm or warning signals or are associated with discomfort and excitement. The social rumbling occurs most frequently in all elephant species, the lower-frequency sounds are also associated with the higher-frequency sounds. Certain differences between the species can be observed here, since both the African and the Asian elephant have a combination of higher / lower frequency versus lower / higher frequency. This is not the case with the forest elephant. The differences may be due to the landscape, as the more open areas that the African and Asian elephants inhabit have a stronger wind influence than the closed forests of the forest elephant. Wind, however, has a stronger influence on low-frequency sounds, so that a sequence of sounds with high frequencies at the beginning is more likely to attract potential listeners. A specialty is the imitation of strange sounds up to and including human language, a skill that otherwise rarely occurs in mammals. This may be related to individual recognition within the fission-fusion social structure. With the aid of acoustic signals, elephants not only differentiate between native and non-native organisms and can also assign them to certain categories based on their own experiences.

In addition to complex communication, elephants also have remarkable cognitive abilities. Sun produced a mirror test of zoo animals of the Asian elephants that they have a self-awareness feature and can recognize themselves in the mirror, similar to magpies , dolphins and apes . In further investigations they learned to differentiate between related pairs of patterns such as “black / white” or “small / large” and were able to remember them for a long time. It has also been proven that elephants are able to count and solve the simplest addition problems as well as compare different quantities. The elephants' memory performance is special in that they recognize and answer the calls of relatives who have emigrated or who have died several years later. Under the influence of extremely negative experiences, the animals may suffer trauma , the causes of which go back to the fetal stage or the effects of which can occur years after the event. Furthermore, the animals show various altruistic behaviors, recognize the needs of other group members or are able to form coalitions for a period of time. Further studies revealed the use of tools or even air to achieve certain goals. The latter in particular should be emphasized, as it requires a certain understanding of the physical environment. A very remarkable behavior is the search for bones and tusks of deceased animals, whereby this applies not only to family members, but also to other conspecifics. These actions are associated with an increased flow of secretions from the temporal gland and intensive social interactions in the environment of the deceased individual.

### Diet and Digestion

African elephant eating branches in the Kruger National Park in South Africa

The elephants are all herbivores . They have an extensive food spectrum, ranging from soft parts of plants such as leaves , twigs , bark , seeds and fruits to hard plants such as grasses . This allows them to be viewed as specializing in mixed vegetable foods. The food spectrum includes several hundred different types of plants. The seasonal composition of the food varies, as a rule the animals tend to eat grassy food in the rainy seasons , while the proportion of soft plants increases in the dry seasons . In addition, there are also strong spatial variations, which is due to the respective local food supply. The seasonal differences in eating habits are often associated with the chemical composition of plants, especially with the protein and carbohydrate content. In general, grasses have a lower protein content than softer plants, but their carbohydrate content is higher. Carbohydrates, in turn, are more easily digestible by elephants of all ages. Too much protein consumption, in turn, requires larger amounts of water, which can be problematic in drier regions. A single animal needs an average of 3 g of protein per kilogram of body weight every day. By consuming grasses in sufficient quantities, an individual can in principle meet his need for both proteins and carbohydrates. In the dry season, however, when fresh grasses are more difficult to obtain, only a small increase in soft plants in the amount of food is sufficient to compensate for the protein requirement.

On average, an individual needs around 150 kg of food (wet mass) every day. The intake of this high amount takes between 17 and 19 hours a day. The proboscis is used for food intake, especially the “finger-like” appendages that individual stalks and grasses can grasp. The animals often scrape off bark with the help of their tusks. About 45% of the grass forage is recycled because the animals have a less efficient digestive system than, for example, ruminants . When resting, an animal needs around 49,000 kilocalories a day. The stomach functions primarily as a reservoir for food, which is pre-digested in the acidic environment at a pH of around 2 . The main part of the food decomposition takes place after passage through the stomach into the appendix and colon with the participation of microorganisms ( bacteria and protozoa ). The entire process, from ingesting food to excreting, takes about 33 hours. The elephant's droppings are relatively coarse and contain a lot of fibrous material. Similar to the horses , it can be partially absorbed again so that the nutrients it contains can be better used. Elephants also occasionally eat mineral-rich soils or seek out salt springs, which supplies the body with important nutrients .

Elephants are water dependent. As a rule, elephants drink water once a day and need up to 140 liters. With increasing aridity of a landscape area, the animals stay closer to bodies of water, in wetter areas the distances to fresh water sources increase. In areas where no water is available, elephants dig small holes with their feet, which in turn allow other animal species to enter.

### Reproduction

#### Rut, musth and mating

Dominance fight among bulls of the forest elephant
Asian elephants mating

Elephants can generally reproduce all year round, but in regions with more pronounced seasons there is a certain seasonalization. The rutting phase of the cows is one of the longest among mammals and lasts between 13 and 18 weeks. It is divided into a luteal phase, which lasts between 6 and 12 weeks, and a follicular phase, which lasts 4 to 6 weeks. There is a short, non-luteal phase between the two phases, during which the production of luteinizing hormones increases twice . Only the second production spurt ultimately leads to ovulation after a period of 12 to 24 hours . The purpose of the first increase in hormones is not clearly understood. It may be part of the elephants' reproductive strategy and enable the cows to attract the attention of bulls ready to mate at an early stage. Another explanation would be to physically prepare the body for impending conception. Because of this long cycle, cows are usually only ready to receive three to four times a year. In the majority of cases a fertilized egg cell is formed , the follicle has a diameter of 21 mm, which is relatively small for animals of this size. The status of the sexual cycle is communicated through low-frequency sounds and chemical signals such as pheromones in the urine . Both communication methods can be used over long distances.

Bull elephant periodically experience a change in sexual behavior, the duration of which can vary widely and which is known as musth . In contrast to the rutting of numerous ungulates, the musth does not start synchronously, but proceeds individually, so that in intact populations there is at least one bull ready to reproduce at any time of the year. The asynchronicity in turn reduces the energetic costs in dominance fights and rivalry. Special characteristics of the Musth can be found in the increased aggressiveness of the male animals. This allows bulls to dominate physically stronger individuals in the Musth. Externally, an increased discharge of secretion from the temporal glands marks the musth status. The musth goes hand in hand with an extreme increase in testosterone levels , with the hormone concentration increasing by up to 100 times compared to the values ​​outside the musth phase. During the musth, bulls increasingly wander around looking for different herds, where they check the genitals and other parts of the cows for individuals ready to mate. The bull signals his own interest by palpating or wrestling with his trunk and neck bite. It attracts more attention to females in the middle part of the rut. During sexual intercourse he is dependent on the cow's cooperation, as his S-shaped, coiled penis can only be inserted into the vulva when it is stationary .

#### Birth and development

Elephants have breast mammary glands here in the Asian elephant with calf in Mudumalai National Park in India

The gestation period is 640 to 660 days or around 22 months, which is the longest of all land-living mammals. As a rule, only one cub is born, the weight of which can be up to 100 kg. At first there are hardly any differences in development between male and female calves. From the age of five to six, male young animals grow significantly faster than female ones. The development in bulls continues into old age, as they can gain body size and weight for almost their entire life. In cows, on the other hand, this process slows down around the age of 30. Bulls are therefore significantly larger and heavier than cows at an older age. Social development is also not in the same direction. The activities of young female animals are always oriented towards the family group. In some cases, they also take care of the youngest offspring ("allomaternal care"). After sexual maturity , young cows usually remain in the mother herd. Young male calves, on the other hand, often seek activities outside the family unit, where they make contact with individuals from outside the group. At around nine years of age, young bulls separate from their mother herd and often join bachelor groups. You enter puberty around the age of 14 . At this point in time, however, their reproductive prospects are still slim, as they lack the physical prerequisites to be able to compete with old bulls. The first musth phase therefore only emerges in the 20s. In general, elephants, both cows and bulls, can reproduce well into old age. In cows, three and a half to nine years can pass between two births. This extremely long birth interval makes cows willing to mate relatively rare in an elephant population and forces bulls to undertake long walks in order to visit different herds. The maximum age in the wild is assumed to be around 60 to 65 years in intact landscapes, which is associated with the failure of the last molar. In areas with high hunting pressure on the part of humans, but under certain circumstances also in human care, life expectancy can decrease rapidly.

### Natural enemies and ecological importance

In the Chobe National Park in Botswana, lions occasionally prey on elephants

Due to their size and herd life, elephants have few natural enemies. Only the largest big cats such as lions and tigers sometimes succeed in capturing young animals. In some areas of Africa, lions chase elephants more often than previously thought. It is an adaptation to the dry seasons, when most of the ungulates have migrated to more food-rich areas. The majority of the captured elephants are formed by young animals that have just left their maternal herd. In the Ice Age, elephants also had to fear the saber-toothed cats , which have now become extinct . For the genus Homotherium in particular , it could be shown at least locally that the animals occasionally killed a young proboscis.

Elephants play an important role in the ecological network of their respective region. They are therefore viewed as ecosystem engineers . Their function manifests itself, for example, in the transport of eaten seeds over sometimes considerable distances, which leads to the further spread of plants. As a further effect, the seeds of individual plants achieve a higher germination capacity after they have passed through the gastrointestinal tract of the elephant. Debarking or kinking trees opens up closed forest landscapes and thus creates spaces for other animal species, as more structured habitats are created. In addition, such open areas can be populated by pioneer plants. Well-trodden paths and paths are visible over tens of kilometers in some landscapes and are also frequented by other mammals. In addition, water holes, puddles in step seals or even leftover excrement serve as places of retreat or reproduction for the most varied of living beings. In addition to the numerous positive effects, an excessive population of elephants in a region can also have devastating consequences for the landscape with dramatic changes. Above all, the interaction between elephants and the grassy landscape or tree population has only been incompletely investigated.

## Systematics

### External system

Internal systematics of the proboscis according to Cozzuol et al. 2012
Proboscidea

Elephantiformes

Gomphotherioidea

Elephantoidea

 Elephantidae

The elephants (Elephantidae) are a family within the order of mammoths (Proboscidea). Today they are the only member of this taxonomic group, which is why it can be regarded as currently monotypical . The proboscis, in turn, are grouped together with the manatees (Sirenia) and the snakes (Hyracoidea) to form the parent group of the Paenungulata , the latter together with the Afroinsectiphilia constitute the Afrotheria , one of the four main lines of the higher mammals with a largely originally African origin. According to molecular genetic studies, the Afrotheria originated in the Upper Cretaceous 90.4 to 80.9 million years ago. About 15 million years later, this group of origins split into the two main lines of today. Within the Paenungulata, the manatees and the proboscis are to be regarded as a closer relational unit, which is referred to as Tethytheria . They split in the Paleocene around 64 million years ago. The fossil record of the proboscis goes back about as far , making them a very old group. In the course of their tribal history, they proved to be very rich in shape, with the high degree of diversification arising as a result of several radiation phases . The individual representatives showed various adaptations to different biotopes and climatic regions. The former distribution of the proboscis reached from Africa to large parts of Eurasia and America . The elephants are to be regarded as a relatively young line of development within the proboscis and form part of the last phase of expansion that began during the Miocene . They systematically belong to the superfamily of the Elephantoidea . This also includes the Stegodontidae , which are to be understood as the sister group of elephants. The earliest fossil records of elephants are around 7 million years old.

### Internal system

Internal systematics of the elephants based on skeletal anatomical features according to Cozzuol et al. 2012
Elephantidae

Internal systematics of elephants based on genetic traits according to Meyer et al. 2017
Elephantidae
Elephantini

Loxodontini

Two subfamilies are distinguished within the elephants: the Stegotetrabelodontinae and the Elephantinae . The former are only known to be fossil and were largely restricted to Africa and the Arabian Peninsula . They are characterized by a long mandibular symphysis, well-developed lower tusks and low-crowned molars with only a few enamel folds, which are also interrupted in the central axis of the tooth when they have not been chewed - a primal characteristic for proboscis. The skull already showed the front and back compression typical of elephants. It is sometimes assumed that the Stegotetrabelodontinae are the parent group of the elephants, but more likely they only represent a side branch. The group appeared in the Upper Miocene and disappeared again in the Pliocene . The Elephantinae in turn show a tendency to reduce the lower tusks and to raise the crowns of the molars. The molars are made up of more numerous enamel folds with a minimum of seven on the rearmost tooth. In addition, the median notch on the tooth crowns disappears. The subfamily includes the representatives still living today, which are divided into two genera with three species . The two African representatives are incorporated into the genus of African elephants ( Loxodonta ), the only Asian form belongs to the genus Elephas . According to molecular genetic data, their separation from one another began around 7.6 million years ago. In addition, individual extinct genera are documented that are more or less closely related to today's genera. The mammoths ( Mammuthus ) belong to the closest relatives of the genus Elephas , while Palaeoloxodon , according to recent findings, forms a common group with the African elephants. The closer circle of relatives around the current African elephant representatives is therefore assigned to the tribe of the Loxodontini , that of the Asian to the Elephantini .

### Overview of the subfamilies and genera of the elephants

The elephant family is structured as follows today:

• Family Elephantidae Gray , 1821

The position of Stegodibelodon within the Stegotetrabeldontinae is not entirely clear, as some authors also include it among the Elephantinae. The actual relationships between the individual representatives of the elephants, especially those from the subfamily of the Elephantinae, are complex according to genetic studies. So there are various hybridizations between the two African elephant species, as well as between the higher taxonomic groups of the Asian elephant. In addition, genetic intermingling between different mammoth forms has been proven. The evidence of individual common haplotypes in both recent and fossil elephant species currently goes back to the elephant lineage and suggests that hybridization between individual species began very early and apparently also worked across genus boundaries. From the present day the only known hybrid between an Asian female elephant and an African bull elephant was born in 1978 at Chester Zoo . It was the bull calf " Motty ", which had mixed characteristics of both species, for example in terms of ear size, but died after ten days.

## Tribal history

### Origins and development tendencies

The proboscis are a comparatively old order of mammals. Its origins go back to the Paleocene of northern Africa around 60 million years ago. Different families are distinguished within the order, such as the Deinotheriidae , the Gomphotheriidae , the Mammutidae and the Stegodontidae , which originated during different phases of radiation . From this point of view, the elephants are relatively young, they belong to the third and thus last phase of radiation of the order, which began again in Africa during the Miocene . Some of the older, trunk animal lines already mentioned, which originate from the previous radiation phases, were in part contemporaries of the elephants until the end of the Pleistocene . Evolutive trends within the elephants can be found in the narrowing of the skull in front and behind, which thereby increased in height. The shortening in length had the consequence that the lower jaw was also compressed, whereby the lower tusks hardly found space and receded. In the structure of the molars, the increase in the crown height in the direction of hypsodontia and the increase in the number of enamel folds should be mentioned. In the latter, the melt band thickness of each lamella was reduced as a result of this process. Both changes - the increase in crown height and the number of lamellas - are related to a greater adaptation to grass forage.

### Miocene

Lower jaw of Stegotetrabelodon

The elephant line of development began in Africa in the late Miocene around 7 million years ago. The new proboscis differed from other representatives of the order by the lack of enamel sheath on the tusks and the presence of enamel lamellae on the molars. Both features are considered to be particularly characteristic of the members of the elephant, but the stegodonts independently developed structures similar to the enamel lamellae. The representatives of the Stegotetrabelodontinae belong to the earliest forms of elephants . Their character form Stegotetrabelodon still had lower tusks and molars with very low crowns and only a few lamellae, which were divided in the middle of the longitudinal axis of the teeth. Despite the low tooth crowns, the lamellar structure indicates that the grass content is already increasing in the food spectrum. The majority of the finds are restricted to eastern Africa and the Arabian Peninsula, but some remains are also documented from southern Europe. Lothagam in Kenya deserves special mention , in Europe stegotetrabelodon is documented from Cessaniti in Italy .

With Primelephas , a representative of the modern Elephantinae appeared for the first time in the Upper Miocene in eastern Africa. This form, which is largely only known from the remains of teeth, is relatively well documented from the Djourab region in northern Chad . The finds are spread over several sites such as Toros-Menalla, Kossom-Bogoudi or Koulà, which are between 7.4 and 4 million years old. Further material was found in the Afar triangle in Ethiopia , including in the Awash area , and also in Lothagam and in the Tugen Hills in Kenya. It is not clear from the paleontological findings whether the animals still had lower tusks. A characteristic feature can be found in the enamel lamellae of the molars, separated by deep V-shaped indentations.

Almost at the same time as Primelephas , Loxodonta emerged, evidenced by individual finds in eastern Africa such as the Lukeino and Chemeron Formations in western Kenya, whose age dates between 6.2 and 4 million years. Similar old finds of early members of the African elephants were found in the Langebaanweg site in the southwestern part of the continent. As a rule, the early finds are isolated teeth, some of which are assigned to the species Loxodonta cookei . The typical characteristic of the individual members of Loxodonta can be seen in the diamond-shaped bulge of the enamel of the enamel lamellae of the molars.

The best-known extinct elephant form, the genus Mammuthus (mammoths), also originated in Africa. The earliest form to appear here is Mammuthus subplanifrons , of which remains, for example, came to light in Langebaanweg, as well as in the Awash area or in the Nkondo formation in Uganda . The corresponding age values ​​vary between 6 and 5 million years. Mammuthus subplanifrons was very primitive for a mammoth, it still had low molars with only a few but thick enamel lamellae. So far, the species is largely known from the teeth and lower jaw, there is no skull. However, a tusk fragment associated with some molars from Virginia in southern Africa already shows the distinctive spiral twist, which is also typical for the other generic representatives. Overall, the molars of Mammuthus subplanifrons were found to be highly variable. The rather small amount of finds, however, limits the possibilities for making statements, so that it is currently unclear whether the taxon might not include several species.

### Plio and Pleistocene

In the early Pliocene of Africa, Stegodibelodon from the group of Stegotetrabelodontinae can still be detected, in which the lower tusks were already reduced. However, the lower jaw symphysis was comparatively long, and the central division of the enamel lamellae still existed. The shape has been handed down from central Africa, for example from the Kollé quarries in Chad . Late evidence of Primelephas was also made from here .

Loxodonta achieved widespread distribution in Africa in the Pliocene and Pleistocene , and fossil records are found from the north to the east to the south. First Loxodonta adaurora appeared, a shape similar to today's African elephants, but with low molars. The animals inhabited mosaic landscapes, important sites with remains of the species are from the Awash and Omo areas in Ethiopia, from Kanapoi or from western Lake Turkana in Kenya. Loxodonta exoptata is just as old as Loxodonta adaurora . In contrast to the former, the latter had higher tooth crowns and more tooth lamellae on the molars. The distribution area of ​​the two forms was relatively similar, in addition, Loxodonta exoptata penetrated into central Africa, as finds from Koro-Toro in Chad show. Loxodonta atlantica , in turn, occurred mainly in the Upper Pliocene and Pleistocene in both North and South Africa. The shape shows a strong specialization with extremely high-crowned molars and a higher number of lamellae than with any other generic representative. This indicates a predominantly herbivorous diet. Today's African elephant can be documented for the first time in the Old Pleistocene , again the Awash area should be mentioned here. In contrast to this, the forest elephant has no fossil record. It is also noteworthy that, unlike other elephant forms , Loxodonta has not yet been documented outside of Africa.

Skeletal reconstruction of Palaeoloxodon antiquus

The genus Palaeoloxodon , which is closely related to the African elephant, also originated in Africa, where it developed in the course of the Lower Pliocene. Its representatives developed high-crowned teeth with up to 19 enamel lamellae on the last molar very early, which can be seen as an adaptation to the increasingly dry climate in Africa. Early representatives in Africa belong to the species Palaeoloxodon eokorensis . The shape was introduced using teeth from Kanapoi in Kenya (an originally accepted species from East Africa, Palaeoloxodon nawataensis , is no longer recognized today). Palaeoloxodon was one of the dominant elephant forms in Africa during the Pliocene and Pleistocene. This also includes the huge Palaeoloxodon recki , which has been found, for example, at important sites such as Olorgesailie or Olduvai . The species existed for a long period from the end of the Pliocene to the Middle Pleistocene and was then replaced in Africa by Palaeoloxodon jolensis . The latter persisted until the transition from the Middle to the Upper Pleistocene , as shown by recent finds from the Kibish Formation of Natodomeri in northern Kenya. Basically only transmitted via teeth so far, their high-crowned structure and additional isotope analyzes carried out indicate a predominantly grass-eating way of life. Palaeoloxodon also reached Eurasia in the Pleistocene, from where the most famous representative has come down to us with the equally large Palaeoloxodon antiquus (European forest elephant). Its distribution area spanned large areas of Europe and western Asia. There is a significant collection of finds with several complete skeletons from the Geiseltal . The main diet consisted of a mixed soft and hard vegetable diet, accordingly the species in the areas north of the Alps largely only occurred during the warm periods of the Middle and Young Pleistocene. Further east, in Central and South Asia , the European forest elephant was replaced by the (possibly con-specific) Palaeoloxodon namadicus . Some dwarf elephants descend from the European forest elephant and colonized various islands of the Mediterranean during the Pleistocene . Mention may be made here as representatives falconeri palaeoloxodon (Sicilian dwarf elephant) from Sicily and Malta , palaeoloxodon tiliensis from the island of Tilos and palaeoloxodon cypriotes of Cyprus .

Mummified carcass of Mammuthus primigenius ( Ljuba )

In addition to Mammuthus subplanifrons , Mammuthus africanavus was also present in Africa , but the latter was largely limited to the Pliocene of northern and central Africa. The mammoths reached the Eurasian area at the latest around 3 million years ago. As a rule, these oldest representatives of the mammoths outside of Africa are associated with Mammuthus meridionalis (southern elephant), alternatively there is also the possibility of a stronger fragmentation of the early forms, which are then led under the names Mammuthis rumanus and Mammuthus gromovi . Differences can be found, among other things, in the number of enamel lamellae. Some of the teeth from Cernăteşti in the Little Wallachia in Romania are among the earliest finds in Eurasia , while others are only a little more recent in central Italy and England . Within the Eurasian mammoth line, Mammuthus trogontherii (steppe mammoth) first developed, which lived largely during the early and middle section of the Pleistocene and, with a shoulder height of 4.5 m, is one of the largest representatives of proboscis. The terminal shape is represented by Mammuthus primigenius (woolly mammoth ), which represents the character shape of the cold-age Eurasian open landscapes. They are known as mammoth steppes and housed the so-called Mammuthus-Coelodonta fauna complex , to which the woolly rhinoceros belonged as another eponymous form . As an indication of this cold-age community and the far northern distribution of the woolly mammoth, ice mummies of the animals are occasionally found in Siberian permafrost , some of which have excellent soft tissue preservation. Due to the adaptations of the woolly mammoth to the inhospitable conditions of the cold ages, the species is considered to be the most specialized elephant representative. This is expressed, among other things, in the molars with their extremely high crowns and the large number of enamel lamellae, which sometimes comprised more than thirty. The woolly mammoth also crossed the Bering Strait in the Upper Pleistocene and colonized large parts of North America . The southern elephant or the steppe mammoth had already mastered this before and spread across North America 1.5 to 1.3 million years ago. A separate line was created there with Mammuthus columbi (prairie mammoth). In the course of the Upper Pleistocene, the ranges of both woolly and prairie mammoths overlapped in North America, and intermingling occurred occasionally. Similar to Palaeoloxodon , individual dwarf forms emerged within the Mammuthus line, including Mammuthus creticus from Crete , Mammuthus lamarmorai from Sardinia and Mammuthus exilis on the Californian Channel Islands .

The genus Elephas as the closest related form of the mammoth can be detected for the first time comparatively late. Early finds fall in the late Pliocene and came to light in the Siwaliks in South Asia . They belong to the species Elephas planifrons . This was then replaced at the beginning of the Lower Pleistocene by Elephas hysudricus , which occurred from southern to western Asia . Other representatives such as Elephas platycephalus also appeared at this time, but have so far been extremely rarely detected. Today's Asian elephant has been documented for the first time with certainty from the Upper Pleistocene; individual finds may already point to the Middle Pleistocene. The Malay island world was home to its own form, Stegoloxodon , whose teeth are somewhat reminiscent of those of African elephants. It is a dwarf form, but so far only a few fossil material from Sulawesi and Java is known.

### Holocene and extinction of various elephant forms

There is only a little bit of information about the disappearance of the various elephant forms in the course of the tribal history, due to the sometimes infrequent fossil record . This applies above all to the representatives of the African and South and Southeast Asian regions. In contrast, the extinction of individual elephant species (and other groups of proboscis) in the transition from the Pleistocene to the Holocene has been studied comparatively well , such as various members of the genera Mammuthus and Palaeoloxodon , whose lines of development have completely died out. In Eurasia, the woolly mammoth disappeared between about 12,300 and 8700 years ago. The species probably withdrew from west to east, as the last dates of occurrence in Western Europe are on average older than in northeastern Asia. In the mainland part of North Asia, for example on the Taimyr Peninsula , the woolly mammoth persisted into the Lower Holocene. A small population survived on Wrangel Island until the Middle Holocene 3700 years ago. Another group that survived well into the Holocene was native to the Pribilof Islands off the coast of Alaska and occurred there up to 5700 years before today. The most recent data for the prairie mammoth in North America, on the other hand, are between 11,400 and 9,300 years ago, those of Mammuthus exilis at around 11,000 years.

While the European forest elephant was last detectable in Eurasia around 33,000 years ago on the Iberian Peninsula , some of its descendants survived considerably longer on the Mediterranean islands. In Cyprus, Palaeoloxodon cypriotes was still present around 11,500 years ago, while Palaeoloxodon tiliensis from Tilos disappeared between 4,400 and 3,300 years ago.

The end of several elephant lines in the Upper Pleistocene and the course of the Holocene coincides with the Quaternary extinction wave, the causes of which are widely discussed. Overall, however, the extinction of the mammoths and the representatives of paleoloxodon dragged on over a period of several thousand years and is therefore not a one-off event. Several factors probably play a role here. They are mainly composed of climate changes that caused the outgoing last glacial period and the associated habitat changes . Together with these people, at least locally, humans have exerted an influence on the disappearance or extinction of individual elephant groups, for example through active hunting.

## Research history

The name "elephant" goes back to the Greek word ἐλέφας (elephas) . Its origin is unknown, it may be derived from the Hebrew word ibah , which in turn was conveyed via Sanskrit with ibhas . It found its way into the Latin language, in which ebur stands for "ivory". Elephas was already used in ancient times, but mostly referred to the tusks and less to the animal itself. Elephas was used as a comprehensive and generic term for elephants as early as the 17th century. In 1758 Linnaeus established the genus Elephas in his pioneering work Systema Naturae , in which he included both the Asian and African animals and united them under the name Elephas maximus . It was not until 45 years later that Johann Friedrich Blumenbach separated the Asian and African forms on a species level. With the official introduction of the genus Loxodonta, the generic distinction goes back to an unknown author in 1827, who, however, used a term that Frédéric Cuvier had used two years earlier . The family name Elephantidae based on the generic name Elephas was introduced in 1821 by John Edward Gray . Gray defined the elephants as follows: Teeth, two grinders in each jaw, composed of transverse vertical lamina, enveloped in enamel, and soldered together by a cortical substance ("Teeth, two molars in each jaw, consisting of transverse, vertical leaves, enveloped by Tooth enamel and held together by an external substance ”).

The systematic allocation of elephants varied over time. Linnaeus saw the animals within a Bruta mentioned group also among other manatees , sloths and pangolins included. Blumenbach provided them with various ungulates such as tapirs , rhinos , hippos and pigs . This remained the basic relationship to the end of the 18th and in the course of the 19th century. Étienne Geoffroy Saint-Hilaire and Georges Cuvier summarized all of the ungulates named by Blumenbach in 1795 to form the pachydermata ("pachyderms"), a group that is not self-contained from today's perspective. Cuvier later added the peccaries , hyrax and some extinct forms. In 1811 Johann Karl Wilhelm Illiger introduced the name Proboscidea , in which he classified the elephants and named them after their most conspicuous characteristics. Illiger has not yet pointed out any fossil forms to the Proboscidea. Gray took over Illiger's organizational unit in 1821 and, in addition to the elephants, also included the “ mastodons ”, an ancient group of elephants that is no longer in use today. In his writing from 1811, Illiger had incorporated the Proboscidea into a group called Multungulata ("many hoofed"), which, however, corresponded conceptually to the Pachydermata. Just five years later, Henri Marie Ducrotay de Blainville first broke the construct of the pachydermata, in which he differentiated several groups of ungulates. These included animals with an even number of toes ( onguligrades à doigts pairs ) and those with an odd number ( onguligrades à doigts impairs ). He grouped the elephants as the only members in a higher unit called Gravigrades. Later, in 1848, reached Richard Owen on the recognition and divided the cloven-hoofed animals (Artiodactyla) and the odd-toed ungulates (Perissodactyla) from which he finally split the Pachydermata. He saw the proboscis as basically similar to the odd-toed ungulates, but left them in a separate organizational unit due to numerous peculiarities such as the proboscis.

The close relationship of the elephants or the Proboscidea with the ungulates remained largely unchanged. However, Theodore Gill noted in 1870 a closer bond between the proboscis, the manatees and the snakes, without giving this group a special name. Other authors established similar relationships with names such as Taxeopoda ( Edward Drinker Cope 1880 and 1890s) or Subungulata ( Richard Lydekker 1890s and Max Schlosser 1920s), but each of these proved to be problematic. George Gaylord Simpson therefore established the Paenungulata in his general taxonomy of mammals in 1945 as a new superordinate group for the elephants, hyrax and manatees together with various extinct forms. Simpson saw the Paenungulata as part of the Protungulata. In contrast, Malcolm C. McKenna and Susan K. Bell led the Paenungulata (named here as Uranotheria) including the elephants generally within the Ungulata. In numerous systematics, the Paenungulata were considered more closely related to the odd-toed ungulate. Only biochemical and molecular genetic studies from the transition from the 20th to the 21st century revealed that the Paenungulata and thus also the elephants belong to a group that is native to Africa and is consequently called Afrotheria .

Numerous scientists have the elephants as a central research topic. In the second half of the 20th century, Vincent J. Maglio did outstanding work on the evolutionary history of elephants. He also created a kinship scheme that largely exists to this day and is based on preliminary work by Emiliano Aguirre from the 1960s. In the following years this was further refined, among other things by the investigations of Michel Beden in the 1970s and 1980s on African fossil finds. More recent studies on the subject were presented by Jeheskel Shoshani and Pascal Tassy in the transition from the 20th to the 21st century; the authors offered a broad overview in 2005. Genetic studies on recent and fossil species are also increasingly fine-tuning the elephant system, with Nadin Rohland in charge . In addition to Shoshani, George Wittemyer and Raman Sukumar were primarily concerned with the more recent species in the late 20th and early 21st centuries . The field research by Joyce H. Poole and Cynthia J. Moss , which contributed important insights into the way of life and social structure of elephants, must also be emphasized. William J. Sanders and Adrian Lister mainly focus on the early elephant forms as the focus of their scientific work .

## Elephants and people

### Elephants in human history

#### prehistory

Relationships between humans and elephants go back hundreds of thousands of years. The body of the elephant served as an important raw material resource, be it for food purposes or for the production of tools or art objects from bones and ivory. Elephant remains can be found relatively often at sites of early human groups from the Old and Middle Paleolithic (2.5 million to 40,000 years ago), for example the southern elephant in Barranc de la Boella in Catalonia , the European forest elephant at the Weimar station. Ehringsdorf in Thuringia or in Geiseltal in Saxony-Anhalt or in Ficoncella and Polledrara, both in central Italy, as well as Palaeoloxodon recki at the Namib IV station in the Namib in southern Africa or in Fejej in Ethiopia in eastern Africa. A distinct use of the carcass can be determined at individual sites, such as in Gröbern in Saxony-Anhalt. It is not entirely clear whether the animals were actually hunted at that time, but the approximately 120,000-year-old lance from Lehringen , which was stuck in the skeleton of a European forest elephant and was associated with more than two dozen flint artifacts, suggests. Occasionally the early humans also made devices and tools from elephant bones or used the remains of the animals in a possibly artistic context, for which the mammoth tooth lamella from Tata in Hungary should be emphasized.

Fully plastic mammoth depiction from the Vogelherd cave in the Swabian Alb , approx. 40,000 years old
Mammoth carved into slate from Gönnersdorf near Neuwied , approx. 15,000 years old

Relations with elephants became more intense in the subsequent Upper Paleolithic (40,000 to 10,000 years ago). Not only are there indications of active elephant hunting, as is shown by the finds of mammoth carcasses with hammered projectile tips from various sites in Siberia or Eastern Europe, but elephant parts were also used much more frequently as a source of raw materials for the production of tools and equipment. The bones and tusks were also used in small arts . They were painted or, in some cases, provided with incised patterns, while others were reworked into small figures. The lion man from the Hohlenstein -Stadel in Baden-Württemberg or various Venus statuettes such as the Venus von Brassempouy in France are outstanding . At the same time, this also includes depictions of elephants themselves, with the woolly mammoth being the godfather in almost all known cases. These are available both as scratch drawings and as small sculptures and can be regarded as the oldest depictions of the animals. Those from the Vogelherd cave in Baden-Württemberg or from Dolní Věstonice in Moravia are known, which date between 40,000 and 20,000 years ago, or a little later from Gönnersdorf in Rhineland-Palatinate. Sometimes it is not only objects of artistic importance, but also objects with a practical function, as demonstrated by the Bruniquel spear thrower in France. Relatively unique is a mammoth carving from Old Vero in Florida , which probably represents a prairie mammoth and represents one of the few known Paleo-Indian art objects. In addition to mobile cabaret, mammoths were also portrayed in cave art , depictions have been passed down from the Iberian Peninsula to the Urals . Outstanding here are the Chauvet cave , the Rouffignac cave with a particularly large number of mammoth drawings, both in France, or the Kapova cave in Russia. In the French Cantabrian cave art alone , mammoths can be found in around a sixth of the around 300 known caves with wall art and make up 6% of all animal representations, making them one of the most frequently portrayed animals alongside wild horses, aurochs and bison, ibex and deer. The mammoth bone huts of Mesyn and Meschyritsch in Ukraine can be named as a further specialty . With the extinction of the mammoths, their visual representation also ended. From prehistoric times, however, representations from northern and southern Africa as well as from India are documented that concern both the African and the Asian elephant.

#### antiquity

Seal of the Indus culture depicting a unicorn (left), a cattle (center) and an elephant (right), 3rd millennium BC Chr.

From the 3rd millennium BC onwards, elephants gained greater importance. In the Bronze Age Indus culture in today's Pakistan , the animals were engraved on small seals made of soapstone. The finds suggest that the Asian elephant may have been tamed and possibly kept as a workhorse at this time. At the latest since the middle of the 2nd millennium BC Indian writings report on the taming and keeping of elephants. Because of their great strength, they were mainly used as workhorses. Lore about a use as a war elephant go back to the 4th century BC. From India the knowledge about the taming of the Asian elephant spread over Southeast Asia to East Asia . In the following years he was also integrated into religious ceremonies. His partly sacred significance in the region is reflected in the elefantengesichtigen god Ganesha of Hinduism and in the birth of the legend, Siddhartha Gautama in Buddhism resist. In his honor, among other things, stone sculptures adorn temples and palaces. Special elephant schools have been set up to tame wild animals, and animal trainers are called mahuts . This centuries-old tradition is largely passed on in the family. It must be said, however, that despite a widespread belief that the Asian elephant was never domesticated , it is rather a question of taming wild animals. After the death of an elephant, new individuals must therefore usually be captured from the wild.

In ancient Egypt , elephants were known, but played no role in everyday life. Occasionally, however, there are temple reliefs of the animals. However, the ivory of the tusks was very popular. Among other things by Thutmose III. is around 1446 BC Chr. The hunt for 120 animals in Syria handed down. There were in river regions until the 8th/7. Century BC Chr. Elephants native. Their closest genetic relatives can now be found in Southeast Asia, which is why some scientists assume that the animals were anthropogenically introduced into West Asia. The ancient Greeks only knew ivory as a commercial object. The first exact descriptions of the animals date back to the early 4th century BC. When the scholar Ktesias of Knidos returned from the court of the Persian great king Darius II . During the campaigns of Alexander the Great against the Persian Empire, the Greeks met his war elephants for the first time, starting with the Battle of Gaugamela . Impressed by the efficiency of the animals, Alexander began to build his own elephant army. After his death in 323 BC The war elephants were used in the Diadoch Wars. With the victory of Ptolemy I over Perdiccas , the animals came to North Africa. In the period that followed, the Ptolemies , cut off from the spread of the Asian elephant, tried to replace them with African elephants, which they captured in what is now Eritrea . The use of the African elephant by the Ptolemies led to the battle of Raphia in 217 BC. BC first representatives of both species as participants in the war. Around the same time, the Carthaginian general Hannibal used war elephants to cross the Alps on his march towards Rome in the Second Punic War .

Fight of an elephant against a big cat, mosaic from the villa of Constantine the Great in Antioch, today Turkey, 4th to 5th century

The Romans themselves were elephants for the first time in the Battle of Heraclea around 280 BC. Encountered. The opposing side under Pyrrhus I used numerous war elephants in this conflict and defeated the Roman troops, who fled in the face of the huge animals unknown to them. Five years later, the Roman military leader Manius Curius Dentatus triumphed over Pyrrhus in the Battle of Beneventum and showed the inhabitants of Rome for the first time some captured animals during his triumphal procession . Around 250 BC During the First Punic War in Sicily , the Roman consul Lucius Caecilius Metellus defeated the Carthaginian general Hasdrubal and his army, which included 120 war elephants. Metellus brought the elephants to Italy on rafts and also took them with him on his triumphal procession. At the latest by 200 BC. The Romans had incorporated war elephants into their army, which deployed during the Second Macedonian-Roman War , among other things . Elephants were not only used as weapons of war, but served from 169 BC. Also in exhibition fights against animals and people. The inauguration of the first stone theater in Rome by Gnaeus Pompeius Magnus in 55 BC should be mentioned here. BC, where among other things 20 elephants were slaughtered. In addition, elephant tricks were performed for amusement , at least during the Roman Empire .

According to Ktesias of Knidos, in antiquity, above all Aristotle in his zoological work Historia animalium and Pliny the Elder in his Naturalis historia dealt with elephants, the latter referring to the now lost work of the Mauritanian king Juba II . The animals were repeatedly depicted on coins in ancient times, especially among the powers that had elephants in their armies (Ptolemies, Seleucids , Carthaginians), but also among the Etruscans and later the Roman emperors. Similar small-format representations can also be found on antique gems . In late antiquity, larger-format illustrations of elephants appeared, in mosaics with hunting scenes and in the new genre of illumination .

#### Middle Ages and Modern Times

Commemorative coin for Soliman , 1554

The importance of the elephant as a war animal, a sacred animal and a status symbol continued later. Akbar , one of the most important Mughals , defeated his opponent Hemu in the Second Battle of Panipat in 1556 , in whose army 1500 war elephants also participated. Later, around 1580, Akbar himself marched with around 500 war elephants and 50,000 soldiers towards Kabul and finally unified the empire. The various Mughal rulers had hundreds of elephants in their stables, some of which were classified into up to seven classes. Special merits were sometimes rewarded with the gift of an elephant. In addition to the war, elephants were also used as mounts for hunting and exhibition fights. The representation of imperial size by elephants passed over to the European territories and intensified especially during the colonial period , when the animals were sometimes diplomatic gifts. As a result, individual elephants have gone down in European history by name. Mention should be made here of “ Abul Abbas ” (9th century), “ Hanno ” (16th century), “ Soliman ” (16th century) and “ Hansken ” (17th century). As a rule, they were representatives of the Asian elephant, more rarely, as in the case of the elephant Louis XIV. , Those of the African elephant . Some elephants had contemporary fame and popularity. These include, for example, “Hanno”, who was portrayed several times by Raffael , among others , including a life-size fresco at the entrance to the Vatican Palace , which, however, is no longer preserved. In the case of others, however, their importance only became apparent afterwards, such as “Hansken”, whose skeleton was elevated to the type of the Asian elephant in 2014 . Most of the animals given away ended up in the menageries of the European aristocratic houses, while others went on tours as attractions. In the transition from the 18th to the 19th century, the menageries were replaced by zoos that were largely open to the public , with cities such as Vienna, Paris and London forming the beginning. Special facilities for elephants were created very early on, for example in Paris in 1808 or in London in 1831.

In modern development, the elephants are among the most popular zoo animals due to their impressive size. Due to their intelligence, they are suitable for dressage in the circus . However, keeping such large animals is not without problems. On the one hand, it leads to conflicts and accidents with people; on the other hand, poor and inappropriate accommodation can lead to various behavioral disorders, of which the rhythmic to and fro ( weaving ) is perhaps the best known.

### Human-elephant conflicts

Today, the Asian elephant is native to around a dozen countries in South, Southeast and East Asia, while the African elephant lives in around three dozen countries in sub-Saharan Africa. The occurrence of the forest elephant in Central and West Africa, on the other hand, has not been well studied. In southern Asia, the population of the Asian elephant partly coincides with the highest population density of humans. Several countries with elephant populations are among the poorest in the world. In particular, the increasing narrowing of the elephant's habitats leads to conflicts with local people. These are recorded by the "Human Elephant Conflict" statistics (HEC). Due to their body size and social way of life and the resulting space and food requirements, the elephants are often in competition for food resources with humans. This leads to, for example, looting of fields or excessive use of water sources in arid areas by elephants. In addition, like humans, elephants are able to exert a strong influence on their immediate environment ( ecosystem engineering ). The resulting conflicts not only lead to economic damage for the people affected, but in extreme cases can also have a fatal outcome. According to estimates, between 150 and 400 people die each year in clashes with elephants in India alone, and up to 500,000 families are additionally affected by damage from field looting. For Sri Lanka, the number of people killed is up to 70 annually, while in Kenya around 200 people lost their lives between 2010 and 2017. On the other hand, hundreds to thousands of elephants are killed by humans every year - often by farmers who want to protect their field crops or in retaliation for human deaths. Other animals die from the effects of human conflict, such as land mines . Poaching is an additional factor. In 2009, the number of elephants poached for the ivory trade in Africa was estimated at 38,000 animals per year.

Avoiding or reducing human-elephant conflicts is one of the challenges of nature conservation. There are currently various ways of minimizing collisions with or damage to economic areas by elephants. Priority is given, for example, to the maintenance or establishment of protected areas and migration corridors, which enable the individual family groups to migrate extensively. In the immediate vicinity of people, this also includes physical barriers such as fences and ditches as well as deterrence through fire, noise, light or the creation of buffer zones with inedible plants such as chilli . Such obstacles can have a strong local influence on the migratory movements of the animals. There is also the possibility of installing detectors that warn in good time of the arrival of groups of elephants. A measure that has been used more frequently in the past, especially in Africa, is the culling of entire herds. But it is declining, rather problematic individuals or groups are being relocated today. To further reduce human-elephant conflicts, a better investigation and identification of possible sources of conflict is necessary. The recognition of such potentially problematic regions then makes it possible to create alternatives for both the affected people and the animals.

### Threat and protection

The greatest threat to the three elephant species that exist today is illegal hunting. This occurs mainly because of the tusks , with meat as a food resource and skin and bones as a source of raw materials. In addition, the destruction of habitats through deforestation and urban sprawl as a result of the spread of human settlements and economic areas have extremely negative effects on the populations. This also leads to the human-elephant conflicts already mentioned. The IUCN classifies the Asian elephant as "threatened" ( endangered ). The game population is estimated to be between 41,400 and 52,300 animals, approximately half of which live in India. There are also around 14,500 to 16,000 individuals who are kept as livestock . The African elephants are considered "endangered" ( vulnerable ), but the IUCN does not differentiate between the individual species. In total, around 352,000 elephants live in Africa, with the largest proportion in the northern part of southern Africa and in East Africa. All three current species are listed in the Washington Convention on the Protection of Species (CITES) in Appendix I, which means that supra-regional and international trade in living specimens or parts of dead individuals is prohibited. Both the Asian and the two African elephants are present in numerous nature reserves. The important challenges include maintaining and protecting the habitats and migration areas of the individual populations, even across borders, as well as reducing conflicts between elephants and humans.

## literature

• Larry Laursen and Marc Bekoff: Loxodonta africana. Mammalian Species 92, 1978, pp. 1-8
• Adrian Lister and Paul Bahn: Mammoths - Giants of the Ice Age . Thorbecke Verlag, Sigmaringen 1997, pp. 1–168, ISBN 3-7995-9050-1
• Jeheskel Shoshani and John F. Eisenberg: Elephas maximus. Mammalian Species 182, 1982, pp. 1-8
• Jeheskel Shoshani and Pascal Tassy (plus other authors): Order Proboscidea - Elephants. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London, 2013, pp. 173-200
• G. Wittemyer: Family Elephantidae (Elephants). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 2: Hooved Mammals. Lynx Edicions, Barcelona 2011, pp. 50-79, ISBN 978-84-96553-77-4

## Individual evidence

1. G. Wittemyer: Family Elephantidae (Elephants). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 2: Hooved Mammals. Lynx Edicions, Barcelona 2011, pp. 50-79, ISBN 978-84-96553-77-4
2. Jeheskel Shoshani and Pascal Tassy (plus other authors): Order Proboscidea - Elephants. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London 2013, pp. 173-200
3. ^ Donald R. Prothero: Rhino giants: The palaeobiology of Indricotheres. Indiana University Press, 2013, pp. 1-141 (p. 105), ISBN 978-0-253-00819-0
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## Remarks

1. Record values ​​often given in the literature with body heights of 4.16 to 4.42 m were taken on hunted animals from southwest Africa in a lateral position; the lying position leads to anatomical changes, as a result of which the measurements cannot be regarded as correct. The total length of these animals from 10.4 to 10.7 m is also imprecise, as it was measured from the tip of the trunk to the tip of its tail (values ​​from the Guinness Book of Records 1992 and Animal Records 2007). The procedures mentioned do not correspond to the correct anatomical measurement methods for shoulder height , head-trunk length and tail length , which are based on reference points of the skeleton in vertebrates and, among other things, require predetermined body positions. Soft tissues are usually not taken into account in the measurement; this also applies to the trunk, which has no bony substructure.
2. The maximum achievable individual age of an elephant has often been the subject of debate. In antiquity , it was assumed that it was up to 200 years old, which was partially adopted by some naturalists in the 18th and 19th centuries. In the mid-1890s this was limited to around 150 years, based on the assumption that the life span of a mammal is five times the time that the epyphyses of a bone need to grow together (in elephants around the age of 30). In the second half of the 19th century, some researchers reported animals that were over 100 years old. It was not until the beginning of the 20th century that studies of zoo animals showed that hardly any of them were older than 50 years (see also Glover M. Allen: Zoological results of the George Vanderbilt African Expedition of 1934. Part II: The forest elephant of Africa. Proceedings of the Academy of Natural Sciences of Philadelphia 88, 1936, pp. 15-44). Officials view the age values ​​of over 80 years for some zoo animals or individuals in the care of mahouts, which have also been partially given in recent times, with a critical eye. As a rule, they are caught in the wild, the age of which is difficult to estimate (see also HAGR: An Age entry for Elephas maximus. ( [19] )).