The Asian elephant, much like the African elephant is struggling as a species with reproduction issues. So many of the world's Asian elephants are in captivity in wild life preserves or in zoos. The Asian elephant does not reproduce well in captivity. At the rate they are going they will be unable to reproduce quickly enough to replace the species as it dies out.
There are several reasons for this reproductive problem. In the past, elephants in the wild have had the chance to meet several potential mates and were able to choose a genetically compatible mate. Elephants are a social animal among their own kind and they do not always take to just any other elephant they meet.
In captivity, due to the limited number of partners, the female will not always be willing to mate with a particular male. This can lead to injuries and a potentially bad situation if the 15000 pound animals do not get along.
The female Asian elephants in captivity quiet often do not have the normal estrous (physiologic changes that occur at the beginning of the reproductive cycle) changes that are required for reproduction to succeed. This leads them to no interest in mating or fertilizing their eggs.
The estrous cycle lasts from 14-16 weeks. Sometime during the 4th to 6th week the follicular phase (the phase at which the follicle mature) begins. This is when the hormones are elevated. In the 8th to 10th week the luteal phase (the last phase of the menstrual cycle when there is a greater chance of pregnancy) is high There are two surges of luteinizing hormones (the hormone that triggers ovulation in mammals). All of these things combined prepare the uterus for egg implantation in the Asian elephant. It stimulates ovulation and the secretion of progesterone. During the first surge it is called the anovulatory surge and during the second surge it is called the ovulatory surge.
Scientists have been able to study these different phases and are now able to use artificial insemination to help the females reproduce at a higher rate than before. While it is still not an exact science it has caused a small surge in Asian elephant reproduction numbers.
The Asian elephant is pregnant for about 22 months. This is a critical time for the elephants when they are in zoos. It takes a lot of hard work and diligence to keep the female healthy and allows her to deliver a healthy calf.