The endangered Asiatic Lion population

Breitenmoser, U., Mallon, D.P., Ahmad Khan, J. and Driscoll, C. 2008 Panthera leo ssp. Persica. IUCN List of Threatened Species, Cambridge, U.K. Available from:
http://www.iucnredlist.org/details/15952/0

Shankaranarayanan, P., Benerjee, M., Kacker, R.K., and Singh, L. 1997. Genetic Variation in Asiatic lions and Indian tigers. Electrophoresis. 18: 1693–1700.
http://www.freewebs.com/hmgrgcb/publication/Elec%20shankar%20et%20al%201997.pdf

WCT. 2013. Asiatic Lion: history, population, human animal conflict, breeding program. Wildlife Conservation Trust. Available from:
http://www.asiaticlion.org/asiatic-lion-history.htm

WWF. 2007. Critically endangered lion now found only in India. World Wildlife Fund. Available from:
http://wwf.panda.org/about_our_earth/teacher_resources/best_place_species/current_top_10/asiatic_lion_.cfm

 

The population of the Asiatic Lions in Sasan Gir, India is listed as endangered by the IUCN (WWF 2007). The Asiatic Lion used to have a range from the Middle East to India, but now it is strictly found in Sasan Gir, India. The population size of Asiatic Lions found in Sasan Gir, India in 2010 consist of approximately 411 lions (WCT 2013).

Due to over-hunting and an extreme famine between 1901 and 1905 the entire Asiatic Lion population in the late 19^th century reached a size of approximately 12 lions (WCT 2013). A breeding center had to be established where these lions were breed in captivity. The biggest issue with the entire Asiatic Lion population reaching 12 lions is inbreeding depression. 

In 1997, Shankaranarayanan et al. conducted a study to examine the population of 38 Asiatic lions in the Gir Forest Sanctuary in India to determine the extent of inbreeding within the population. Previous research done on the Asiatic Lions had showed that they were highly inbred and had very low levels of genetic variation. Blood samples of the 38 Asiatic Lions were taken and they were analysed using random amplified polymorphic DNA (RAPD) (RAPD is a type of PCR reactions that amplifies random segments of DNA). Shankaranarayanan et al. found that the population of 38 Asiatic lions had an average heterozygosity of 25.82%.  To try and determine the level of heterozygosity found in the subspecies of Asiatic Lions before they had reached an approximate size of 12, the researchers analysed 50 to 125 year old skin samples found in museums. The results showed that these old skin samples had a heterozygosity of 21.01%, which is close to that of the current population. The researchers concluded that Asiatic Lions have always had a low genetic variability, and that it is probably a characteristic of this subspecies. It is interesting that even though the human population almost drove this subspecies to extinction, they somehow managed to bring it back with the same level of genetic variation.


The most crucial error with Shankaranarayanan et al.’s study is: how are they to be sure the old skin samples found in museums were not from the same pride. It seems highly unlikely that they would be able to determine what population these old skins came from.

Thus, even though humans were the cause of the population reaching 12 lions they have also brought the population back to a stable size. In reality we have made progress in conserving the last Asiatic Lion population. Although, I believe more studies need to be done before we can determine if we have actually created a population of highly inbred Asiatic Lions.

It seems like this “revival story” is continuously discussed in conservation: humans destroy an entire population, but then they revive it. It makes me wonder if we will ever learn to try and conserve the population in the first place rather than destroy it and then spend a large sum of money to fix it.
 
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