senses and cognition
and in society
The trunk is a combination of a precision instrument and tree-felling power. Asian elephants have only one "finger" at the end of the trunk, while African elephants have two. Asian elephants use their "finger" by manoeuvering it against the lower edge of the trunk tip, resultign in a grip precise enough to pick up a piece of fruit.
The trunk has many uses, including that of a snorkel for breathing while submerged in water to get rid of excess body heat.
A wild male in musth, revealed by the dark secretion flowing from his temporal gland. As can also be seen in this photo, elephants are quite agile in uneven terrain. The flexibility of their legs and their coordination of body movements are far from the log-like limbs of cartoon caricatures.
Elephants normally give birth to one calf at a time. Twins are very rare. These twins, called Ram Gaj and Laxman Gaj, were born in Chitwan, Nepal in 2008.
Elephants have several physical traits that are rare or unique among animals. One of them is the trunk. Compared to a human hand and arm, it is almost as versatile and more sensitive to touch.
The trunk is a fusion of the nose and upper lip. Its precise movements are carried out by thousands of muscles. During evolution, the parts of the nervous system that control trunks or hands have accordingly become increasingly complex. The versatility of the trunk has probably been one of the factors contributing to the evolution of elephant intelligence.
Tusks and tushes
Tusks are specialized front teeth that grow continuously. Female Asian elephants are tuskless, but some have short tushes, such as the female pictured on the upper left. Some Asian males also are tuskless. Ivory poaching has increased the proportion of tuskless males in many populations.
The skin is on average two to three inches thick, but in some body parts - such as the silky skin behind the ears - it is paper-thin. The surface of the skin is rich with receptors (nerve endings) sensing touch and pain. Touching each other is an important part of social bonding in elephants, which is the reason why their skin has evolved to be so sensitive.
Although far from the versatility of the trunk, an elephant sometimes uses the tail as a "sixth limb" to feel around, for example, to examine a wound on its rump. In playful interactions, when elephants sometimes back up to each other, they can also be seen using their tails for tactile contact with the playmate.
Despite their size, elephants also have their weak points. The spine is one of them. The Asian elephant has an arching back, which makes the protruding spine vulnerable to pressure. Frequent carrying of the weight of a howdah (saddle) and passengers risks causing chronic pain and other problems due to inflammation between vertebrae and pressure to nerves.
Males have repeated periods of musth, or reproductive activity, during which their testosterone levels raise 50- or 60-fold. In Asian elephants, the clearest visible signal is the dark fluid secreted from the temporal gland between the eye and ear, as in the photo on the left. In African elephants, temporal secretion occurs in both males and females and in any situation of excitement, while Asian females only secrete towards the end of the pregnancy and soon after giving birth. Contrary to popular belief, musth does not make males "mad". Musth aggression, often observed in captivity, is mainly a result of adverse experiences in captivity, such as stress from painful handling and restricting of natural leg movements with chains. It may also partly be due to impaired social behaviour due to insufficient opportunities to socialize with other elephants while growing up.
A female elephant is receptive to the mating by males for only a few day in each estrus cycle. An estrus cycle lasts for about three and a half months. Elephants are slow breeders, investing a lot in each calf: the gestation period (pregnancy) lasts of almost two years, and there is an interval of several years between births.
The natural diet of elephants consists of a larger variety of plant species than that of any other plant-eating mammal. In the wild, elephants have been documented eating several hundreds of different plants.
Because of the large body size, dissipating extra heat is a crucial issue for elephants. Heat loss mainly takes place via the surface. The larger an animal is, the less surface area it has relative to its body weight. Moreover, elephants have very few sweat glands, only between the toes. In warm weather, elephants need water or mud to cool themselves down. In the absence of water, elephants may also throw dust or sand on themselves to cool down. This helps a little, but is not nearly as effective as getting the skin wet.
Copyright © Elephant Experts 2014-2016
Photo copyright © Elephant Experts and the photographers:
Minna Tallberg, Helena Telkänranta, Marc Pierard, Karpagam Chelliah,
Nirvay Sah, Sudhir Yadav and Ramesh Belagere