Breeding for purity

Breeding of lions in zoos has so far been haphazard. Records of a lion8217;s pedigree have not been kept, and not much is known about the lineage of the lions in captivity. Many are hybrids 8212; which improves vigour 8212; but then there is also the need to preserve some pure specimens so that the Asiatic lion survives. In the Gir sanctuary, there has been so much inbreeding that the younger generations are turning infertile.

The lion population itself is small 8212; by the 1995census there are 304 of them in the wild. And now, the very survival and identity of the Asiatic lion, which walked into the bowl-shaped Saurashtra region some 50,000 to 1.5 lakh years ago, is at stake.

The enormity of the problem becomes obvious if one visualises an epidemic breaking out in the Gir area, the only home to the Asiatic lion. The entire population of Asiatic lions of pure breed will be wiped out. The consequences will be all the more disastrous if the zoos do not have animals of pure breed.

Explaining the rationale of the project, S C Sharma, additional inspector general of forests wildlife, who also holds charge as CZAI member-secretary, said, quot;So far, the zoos used to take the same litter, and keep them together, leading to inbreeding among members of the same family. Inbreeding leads to loss of genetic diversity, which ultimately affects the animal8217;s capacity to fight diseases and infection.quot;

According to Sharma, the aim of the project is to create a gene pool reserve of the AsiaticLion breed, which could be released in the wild if needed. The project aims to create a reserve population of pure Asiatic Lion, which is genetically and physically a viable population.

But in zoos, a lot of hybridisation has taken place between different breeds of the species, mainly the Asiatic and African. CZAI says there are around 200 hybrid lions and 85 pure Asiatic Lions 58 females and 27 males. quot;There never was planned breeding of Asiatic Lion before,quot; said Vipul Chakrabarty, scientific officer, CZAI.

But what led to so much of hybridisation? quot;The zoos never kept record of where the animals came from till The Wildlife Protection Act came into existence in 1972. The zoos did not maintain geneaological charts either,quot; says B C Chaudhary, scientist at the Wildlife Institute of India, Dehradun.

But hybridisation did not serve the conservation purpose as the number of pure Asiatic Lions in captivity dwindled, though the hybrid-lion population might have gone up, said Chaudhary. However, CZAI hasnow banned hybridisation of the Asiatic Lion.

But the bigger and subtler enemy of the Asiatic Lion is inbreeding. quot;Inbreeding leads to a reduced genetic variation. And lesser the genetic variation, greater the risk of catching infection. This also leads to much greater chance of infant mortality,quot; says Chaudhary. quot;In short, nature does not permit any unfit individual to survive,quot; he added.

Lalji Singh, scientist at Centre for Cellular and Molecular Biology CCMB, Hyderabad, also echoes similar views. quot;In-breeding in the long-run leads to infertility in the breed. If they animals are homogenous, chances of inheriting defective genes from the both parents are very high. This leads to a fall in the birth rate and a higher infant mortality rate.quot;

Singh who has led a group of scientists to conduct a study on genetic variation among Asiatic lions and Bengal tigers, says that animals which are highly in-bred ultimately become extinct. However, Singh counters the findings of a study conducted by USresearcher Stephen J O8217;Brien, who concluded that there is no genetic variation in the captive population of Asiatic lions. quot;There is about 25-30 per cent genetic variation in the Asiatic lions. So, things haven8217;t reached a stage of no return,quot; he says.

Welcoming the CZAI project, Singh says that the gene pool of Asiatic lion quot;should not be pollutedquot;. However, Singh also blames fast-depleting forest cover as a factor that forced animals to in-breed. According to him, dwindling forest cover, splits the animal population is groups, forcing them to in-breed.

Sharma said that a certain minimum number of unrelated animals or founder population8217; is required for such a project. Under this project, 10 pairs of pure Asiatic lions 10 males and females each would be given to select zoos. The project will be monitored by the CZAI and Sakkarbaug Zoo, Junagadh, which belongs to the State forest department. In fact, the Sakkarbaug Zoo will maintain the stud book geneaological chart for the entire project.

However,Sakkarbaug zoo officer R D Katara said that so far five zoos had been identified, which would be given 15 pure Asiatic lions among them. These zoos are: Sakkarbaug Zoo, Junagadh; Kanpur Zoological Park; Arignal Anna Zoological Park, Chennai; Hyderabad Zoological Park and National Zoological Park, New Delhi. He said even the lions to be given to the zoos have been identified in consultation with CZAI. The project will be monitored by one representative each of the Sakkarbaug Zoo, the concerned forest department, and CZAI, he said.

Sharma said that aim of the project was to raise the population to about 200-250. However, he said that it it was a continuous project, which would take off as soon as transportation for the identified lions was arranged. He maintained that the project would be implemented scientifically and no related Asiatic lions would be allowed to breed. quot;Even one-year-old litter will be separated,quot; he said.

But scientists also believe that besides such a project, the chances of the Asiaticlion8217;s survival could be enhanced by creating a second home for them.