National Geographic Today
It is a tough blow to a lion's pride when the jungle royalty must depend
on humans for its reproductive success. But in some parts of South
Africa, lions have lost much of their habitat and their roaming grounds
have been seriously constricted. The result: inbreeding, which
scientists believe cause genetic defects and infertility.
Today wildlife experts in some smaller reserves are experimenting with artificial insemination and vasectomies to boost the lions' gene pool. Artificial insemination has been used successfully with other big cats in zoos but never before with lions, captive or free ranging.
Inbreeding has also plagued wild elephant, rhinoceros, buffalo, and antelope populations. One solution has been to simply move some individuals to another reserveinfusing the local populations with a blast of new genes. But this approach is not as easy for lions.
"You can't just dump a group of lions into a new area because the resident lions will chase them out or kill them," said Paul Bartels, a wildlife veterinarian and director of the Wildlife Biological Resource Center of the Endangered Wildlife Trust, outside of Johannesburg. "Lions have a very intricate social structure."
Before fences and highways lions roamed vast distances, sowing their seeds far and wide. But as their domain shrank, some parks could accommodate only a few prides, which then began to inbreed.
Need for New Blood
Lions live in prides, family groups made up of a number of females and one or only a few male leaders. Before their habitat shrank, young lions introduced new blood by challenging and replacing the dominant males every few years. But as parks accommodate fewer prides, older males remain unchallenged and mate with their offspring.
Hluhluwe-Umfolozi Park (HUP) in KwaZulu Natal, for example, has an unusually inbred population120 lions sprung from just three lions introduced to the park in the 1960s.
Genetic analysis of HUP lions revealed sperm abnormalities and increased disease susceptibility. The animals were also about 20 percent smaller than lions from other parks, says Rob Slotow, a professor at the University of Natal in Durban and leader of the Natal Lion Project, established in 1996 to unify conservation efforts.
Slotow favors introducing adult female lions and established prides to regions of parks where there are no resident lions. He is monitoring lions released in Hluhluwe-Umfolozi to test this approach.
Bartels said to move the genes without displacing the lions.
In a project begun a little over a year ago, Bartels sterilizes pride males that have sired around 20 cubs. The lion is darted and once asleep is given a vasectomy. During the operation sperm is collected for the tissue bank and will later be used to inseminate lions in another park. "Darting Safaris" are used to fund the work and have become quite popular, Bartels said.
But handling lions can be hair-raising, Bartels said. "I've had a male lion, who wasn't quite asleep, jump up and bite me." The lion chased Bartels to the gate of the enclosure and leapt toward him, jaws aimed at his head. Bartels blocked the attack with his arm, which became tightly locked in the lions jaw. Bartels ceased struggling, mimicking dead prey, and fooled the lion into relaxing his jaws. He escaped.
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