BACKGROUND TO SOUTH AFRICAN LION DIVERSITY

Although South African lions share common ancestors, distinct populations have developed due to a decreases in range and increases in isolation of different lion populations.

Genetic diversity is essential for survival of any species, yet there are indications that some reserves in South Africa are facing inbreeding issues, which reduces genetic diversity. Inbreeding has been shown to affect reproductive success as well as increase susceptibility to disease.

In large, open wildlife systems, such as the Greater Kruger National Park, inbreeding is prevented through the expected social behaviour of lions - where young males leave their natural pride before they are old enough to challenge for pride tenure.

Conservation genetics involves conserving the maximum genetic diversity within a species, which will preserve their evolutionary potential, and their ability to cope in a changing environment.

Genetic diversity provides the basis for adaptability through natural selection as environmental conditions change. Therefore, a population which lacks genetic diversity is in great danger of not having the natural resources to survive environmental change. In practice 'inbreeding' or loss of genetic diversity may result in reduced survival, reproductive abnormalities, juvenile mortalities, physical deformities and reduced growth of populations.

Genetic analysis of the Timbavati lions by Dr Desire Dalton and Susan Miller has indicated that our lion population has high genetic diversity and is not at all at risk of inbreeding. This is a healthy state which is enhanced by the vast ranges available to lions in the Greater Kruger National Park open system.

Not surprisingly, the Timbavati lions are genetically most closely related to those of the Kruger National Park (rather than to Lions in Namibia and Botswana).

THE TIMBAVATI LIONS

Whilst there are isolated reports from time to time of white lion sightings in the Kruger National Park and there are many white lions bred in captivity and semi- captivity both locally and abroad, the Timbavati Private Nature remains the only reserve in the world (as far as we know) where wild white lions occur regularly and naturally.

Much has been written about the white lions. Books have been published about them. Some people credit them with having mythical powers. Some say they’re albinos, others that they’re leucistic. In fact, the white lions of the Timbavati are neither.

In 2013/14 a Timbavati landowner, Dr Graeme Naylor, initiated a research project to establish what the white lions are all about genetically. Apart from the obvious differences between tawny lions and white ones, there are in fact subtle and interesting physical differences amongst the white lions themselves. Some have blue eyes, pink lips, noses and pads, others have brown eyes, black lips, noses and pads.

There was some suspicion that the white lions with blue eyes, pink noses, lips and pads could be albinos and that those with brown eyes, black lips, noses and pads could be leucistic - partial loss of pigmentation.

Research conducted by Dr Desire Dalton looked specifically at nuclear DNA sequencing of the Tyrocinase gene (responsible for albinism) but found that our white lions did not have this mutation. Also, histo-pathological analysis of the eyes of both our brown eyed and blue-eyed white lions, conducted by Dr Gonnie Behr at Ampath laboratories, revealed a reduced, but not absent, melanin (pigmentation) concentration in the blue eyed individuals.

So, our white lions are not albinos.

Dr Dalton isolated a white gene, which is a recessive gene for white lions and only expresses itself if this gene is inherited from both parents. The reason for the variation in lip and eye colour is a differing expression of this recessive gene in different individuals.

So, the white lions of the Timbavati are not leucistic either.

Of the 22 individuals sampled it was found there was a 28% carrier rate of the white gene amongst the general lion population and a 19% carrier rate of the white gene in the phenotypically normal tawny lion population.

The relatively rare occurrence of naturally occurring White Lions in the Timbavati, compared to naturally occurring Tawny Lions, even with the high carrier rate of the white gene within the population, is an indication that the White colouring is not an ideal colour mutation evolutionarily speaking. For this reason, it has remained an autosomal recessive gene, and occurs naturally from time to time, but will never become the dominant colour for wild lions.

Our white lions are also certainly not a separate sub-species, as some people believe.