By Ania Lichtarowicz
BBC health reporter, in Berlin
Assisted reproduction technology, such as IVF and artificial insemination, is making a significant contribution to animal conservation, one scientist says
China says its conservation measures are bearing fruit
Dr David Wildt says the techniques are being used to support populations of orcas, pandas, cheetahs and even black-footed ferrets.
The Smithsonian National Zoo expert says key differences in the biology of animal reproduction are now understood.
He is speaking at the European Society of Human Reproduction and Embryology.
The society is holding its conference in the German capital and Dr Wildt, as a world leader in his field, has been asked to give a lecture on Monday.
There has been much talk recently about using cloning to assist conservation efforts of rare or endangered species, but this technology is currently highly inefficient and unlikely to play a major role in the field in the short to medium term.
Instead, researchers are increasingly turning to existing fertility treatments - many of them developed for human use - as a way of boosting numbers of rare animals.
So far this year, 20 giant pandas have been born in captivity and this is partly thanks to assisted reproduction technology (ART).
Female pandas are fertile for only three days a year, hence the difficulty in breeding. But by using artificial insemination and taking sperm from other breeding centres, the chances of viable offspring being produced increases significantly.
Dr Wildt from the Smithsonian Zoo's Conservation and Research Center told the BBC:
"Artificial insemination is a very valuable technique for genetically managing small populations - moving genes from one location to another; even bringing genes in from the wild so that we never have to take, for instance, another giant panda from the wild.
"We can leave those giant pandas in their native habitat where their very presence protects that habitat."
ART is not a total solution to conservation - preserving habitats and food sources are vital to species survival. But Dr Wildt says it can make a big contribution, giving scientists a much better understanding of why some species may struggle to reproduce.
For example, ART led to the discovery that in cheetahs more than 70% of sperm are abnormally shaped, dramatically reducing fertility. By using artificial insemination and choosing the best sperm, more animals are born that will eventually be reintroduced to the wild.
"The most valuable contribution of reproductive science and ART to conserving endangered animals is the powerful ability to help us understand fundamental reproductive mechanisms in a variety of species," says Dr Wildt, who heads his centre's Department of Reproductive Sciences.
"However, genuine conservation is achieved only when the reproductive knowledge and technologies are integrated with other disciplines in multi-dimensional management programmes. Conservation is like an enormous jigsaw puzzle with lots of pieces.
"ART is only one piece, so with ART alone one could hardly complete the puzzle and contribute to conservation. What makes our field so different (and fun) is the need to work with other disciplines.
"For example, in our studies of giant pandas, we work closely with veterinarians, behaviourists, nutritionists, pathologists, population biologists and geneticists, and that is only on the captive side.
"In the wild, we integrate our work with experts in ecology, landscape management, geographical information systems and even environmental education."