KEY POINTS:
The fastest animal on four legs is also a fast mover when it comes to sexual promiscuity, according to a study of the mating habits of female cheetahs.
Paternity tests of wild cheetahs have shown that almost half of all the litters were made up of cubs from at least two different fathers.
It is the first time the females of a species of big cat have been shown to mate simultaneously with more than one male resulting in litters of mixed parentage.
Scientists said they were surprised by the extent of promiscuity in female cheetahs although they suspected it might take place given that females wandered over wide distances that took them across the territories of several males.
"Before we started the DNA analysis, we thought it was possible that female cheetahs were choosing to be cheaters, but we were amazed by the level of infidelity that we uncovered," said Dada Gottelli of the Zoological Society of London, who led the study.
"It's not been found in other large cats such as the lion, puma or leopard," Dr Gottelli said.
The researchers found that in litters with more than one cub, 43 per cent were fathered by more than one male. In some cases, three fathers were responsible for the cubs of just one litter.
Dr Gottelli said that female cheetahs who mated with more than one male exposed themselves to serious risks so there must be some kind of benefit to such risky behaviour.
"Mating with more than one male increases the risk of exposure to parasites and diseases. Females also have to travel over large distances to find new mates, making them more vulnerable to predation," she said.
"However, the benefit to the females is that their offspring are more genetically diverse, which is important in an unpredictable environment such as the Serengeti."
Over the past 150 years, the number of cheetahs in Africa has fallen dramatically from an estimated 100,000 in the early 19th Century to less than 12,000 now. The species is classified as "vulnerable" and its dramatic decline has resulted in a "genetic bottleneck", with DNA diversity a fraction of its original extent.
Sarah Dunant, the leader of the Serengeti Cheetah Project, said the study showed that male cheetahs, even those living beyond the confines of the national park, were contributing more to the gene pool of the next generation than originally expected.
"This is good news for conservation as the genetic diversity of future generations of cheetah will be preserved," Dr Dunant said.
Female cheetahs are solitary animals and it has been difficult to track which males they mate with because of the wide ranges they can cover. They usually have litters of three or four cubs.
The study could shed light on a little understood aspect of cheetah behaviour, where females sometimes adopt cubs of another mother, the scientists said.
It has been postulated that if adopted cubs are from related females, the "stepmother" may benefit from rearing the cubs of a close relative - so called kin selection.
"This suggests that adoptions between unrelated animals do occur, and lends further support to the suggestion that adoptions are likely to result in real survival or reproductive benefits to cubs, rather than genetic benefits through kin selection," the scientists said.
Understanding the complex nature of cheetah relationships will further our understanding of the animal and help to save the species from extinction, the researchers said.
- INDEPENDENT
