Not much is known about certain rhino ovulation cycles, but it has been confirmed that some do not have set mating seasons and may become sexually active two times per year. Most seem to mate in the summer and fall seasons, likely due to the availability of food.
Female rhinos put on weight and become irritable if they do not
reproduce, according to a study. Experts also discovered that,
although they are ready and willing to copulate, they show no
outward signs, so males do not realize that they are in heat.
Researchers at Chester Zoo teamed up with Manchester and Liverpool
universities to carry out the first comprehensive study into
reproduction among black rhinos. They performed hormone analysis on
animals from eleven European zoos. A total of 9,743 samples were
analyzed by Chester Zoo’s wildlife endocrinology laboratory. Dr
Katie Edwards, from the University of Liverpool, who led the
research, said females that had never bred were found to be heavier
than those that had. Non-breeding females were also found to have
“unpredictable” temperaments. The results were published in the
Journal of General and Comparative Endocrinology.
The male Rhinoceros is ready for mating between the ages of 7 and 8
years old. However, if there are other males to compete with, it can
be much older before it is able to find females that are receptive
to advances. The bigger and stronger males are the ones that have
the best success when it comes to mating. For females mating can
begin from the ages of 5 and 6.
It is common for fierce fights to occur between males and females,
because the male will not take no for an answer when it comes to
mating. The male usually does get his way and then will leave after
The fact that the mother carries the young in her body for more than
one year and she may keep it with her for several years is a problem
when it comes to increasing their numbers. The females may take
three years to mate again.