Reproduction: The male rhinoceros attains sexual maturity at 4 to 8 years of age,
while the females attain this at 3 to 4 years. Testes do not descend into a scrotum
like elephants. The penis is pointed backwards when retracted. As a result, the
urine is squirted behind between the legs. Two teats are located in between the
hind legs. The oestrus cycle in rhinoceros has been reported to be 35 to 60 days.
The oestrus lasts for about 2-3 days and is characterized by frequent urination,
restlessness, squeaking and squealing sounds. Coitus usually lasts from about
half an hour to more than an hour. The peak conception is reported during rainy
season. The female drops a single calf (exceptionally two) after a gestation period
of 15-16 months. The pink colour calf weighs 40-65 kg. depending on the species.
The calf usually remains with the mother for 3-4 years. The calving interval varies
from two to four years and female is capable of producing calves up to 40 years
Behaviour: Rhinoceros are basically solitary animals. They may be grazer (e.g. Indian rhinoceros) or browser (e.g. black rhinoceros). Rhinoceros are active both in day and night. These herbivorous animals often wallow in the mud to regulate their body temperature as well as for protection of skin against biting flies. The male makes a territory which is marked with faeces and urine. In the wild, the rhinoceros often rubs its body against a sloping tree trunk leaving an indication of its presence in a particular area. The rubbed area is often coated with mud. Like a few other animals (e.g. blue bull), the rhinoceros have the characteristics of 11 dung piles". Rhinoceros are also known for their erratic behaviour like chasing vehicles and even butterflies.
Life span: The life span is reported to be 30 to 50 years or more.