Pandas Kai Kai and Jia Jia's failed baby-making antics made headlines two weeks ago, but they are not the only zoo animals that need help.
The Singapore Zoo has tried to rescue the panda situation with artificial insemination and plans to use it more often as a conservation tool.
"We haven't been doing artificial insemination that much, but we will be doing more," said Dr Cheng Wen-Haur, chief life sciences officer at Wildlife Reserves Singapore, which runs the zoo.
Then, a Himalayan tahr - a species of goat - had trouble mating because of a problem with its joints, so vets injected five female goats with its sperm. All five became pregnant.
One reason for artificial insemination is to increase the genetic diversity of the animals. Inbreeding, where closely related animals mate with one another, could put them at risk of diseases, said Dr Cheng.
While a new, genetically unrelated animal can be introduced to breed within the herd, this may result in other problems, such as stress to the animal.
"We encourage the full range of natural behaviour as much as possible," he said. "(Using artificial insemination) has to do with a need and is not a shift in our stand."
Dr Cheng noted that among the Asian elephants at the zoo, a bull, Chawang, has already fathered four calves.
"Bringing in fresh or frozen sperm from another elephant would be much easier than bringing in a full-grown elephant," he said.
Then there are animals which are raised in captivity and do not know how to breed. One example is Charlie, a Sumatran orang utan which was hand-raised by humans in a Malaysian zoo. It moved to Singapore in 2005.
"He thinks he's a human, not an orang utan," said Dr Cheng. Because of the way it was raised, Charlie prefers to interact with the zoo's visitors rather than the female orang utans.
Dr Cheng said: "(Charlie's) genes may have good qualities, such as being resistant to certain parasites.
"If he does not breed, he will not leave any of these advantages to future generations."
Wildlife consultant Subaraj Rajathurai said artificial insemination has become more important in zoos around the world.
"There's nothing wrong with that. It has brought us further into the future," he said.
As for pandas, whose numbers are very low in the wild, Dr Cheng noted that such assisted reproductive technology is "another kit in the toolbox that animal carers can use in the conservation battle".
The artificial insemination on Jia Jia has been given a 20 per cent-to-50 per cent chance of success. The zoo will know for sure after ultrasound scans in a few months.
This article was first published on May 3, 2015.
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