The male’s penis is encased in a sheath but is released for urinating and mating – and the huge size leads to it often being referred to as a ‘fifth leg’! The female’s vaginal opening is located between her hind limbs, not under the tail as in many species. Her mammary glands are located between the forelegs, with one nipple on either side, looking very much like human breasts.
Pregnancy lasts for 22 months – the longest of all mammals. In the third month, the foetus already has well developed ears, trunk and a tail. At birth, calves can weigh about 100 kg – more than most human adults! The newborn elephant measures 90 cm – tall enough to reach its mothers mammary glands between her forelegs, so it is able to suckle. The calf is able to stand 30 mins after its birth, leaning against its mother for support. The calf suckles with its mouth, not the trunk, which at this age, has no muscle tone. To clear its mouth to suckle, the calf will flop the trunk over its forehead. Although it only suckles for a few minutes at a time, the calf will suckle many times throughout the day, drinking up to 11 litres of milk every day.
The calf suckles milk from the mother for 2-2.5 years, but starts eating solid food at about 6 months. In the wild females will have a calf every 3 – 5 years. A calf learns by observing the adults in the herd, not from instinct. A calf will learn to use its trunk by watching older animals. It takes a few months for the calf to gain full control of its trunk. In the early stages the trunk is floppy and rubbery; and calves are often seen to trip on them, as they learn to use them properly.
In the wild, when food is abundant, a female elephant reaches puberty at around the age of ten, becomes pregnant for the first time at about 13 yrs old and can continue breeding until her death at about 60-70 years old. Elephants can make use of an interesting ‘birth control mechanism’ when conditions are not right and food is in short supply: the age of puberty increases, the calving interval becomes longer and older females may stop breeding at an earlier age.
Musth is a phenomenon associated with large breeding bulls. It usually starts from the age of 25. It coincides with an increase in testosterone levels (to six times their normal levels), aggressive behaviour and increased secretions from the temporal gland and urine dribbling. The temporal gland is located just under the skin between the ear and the eye, on either side of the head. It usually occurs annually but in some animals has been known to occur two or three times a year. The word ‘musth’ comes from an ancient Hindi word, meaning ‘intoxicated’.
Musth becomes more regular and lasts longer the older the bull becomes, until after the age of roughly 44 to 46, when these periods become shorter. During musth the bulls walk with high heads and are very aggressive as they look for females who are close to or in oestrous. It is known that females in oestrus follow musth bull’s urine trails in order to attract them. When a musth bull moves in to a breeding herd, the female backs towards him and urinates to demonstrate sexual status. The urine odour of the female changes completely approximately 2 weeks before oestrus and the bull is attracted to this odour. At this stage he will mate with her up to 4 times in the next 24 hours and it is possible that more than one elephant may mate with her at this time. Cows are in oestrus for 3-6 days.
Bulls begin to produce sperm between the ages of 10 and 15 years, although are unlikely to father many calves at this stage. Cows are sexually active during a short period called an oestrus cycle, coming into season every 4 months. They reach sexual maturity from 9 – 10 years of age and can give birth until their mid 50s.