The Timbavati is renowned for its white lion populations. These white lions are not albinos nor are they a different species, their genetic arrangement creates a condition known as ‘leucism’.
Although the South African lions share common ancestors, distinct populations have developed due to a decrease in range (restricted geographical habitation) and isolation of lion populations. (Micro satellite data distinctions can be made between these groups.)
Genetic diversity is essential for survival of any species, yet there are indications that some reserves in South Africa are facing inbreeding issues, which inhibits genetic diversity. (Inbreeding has been shown to affect reproductive success as well as increase susceptibility to disease.)
In large, open wildlife systems, 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 both conserving the maximum genetic diversity within a species, which will thereby preserve their evolutionary potential, and their ability to cope within environmental changes.
Genetic diversity provides the basis for adaptability through natural selection as environmental conditions change. If a population lacks genetic diversity it 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 indicated that this lion population have a high genetic diversity and are thus not at all at risk for inbreeding, which is comparable with the lions in the Kruger Park open system.
Genetically the Timbavati lions, not surprisingly, are most closely related to those of the Kruger Park, as opposed to Lions in Namibia and Botswana.
Different Physical Traits of the Timbavati White Lions
Intriguingly, some of the white lions have blue eyes with pink mucous membranes i.e. pink lips, nose and pads; whilst others have brown eyes with black mucous membranes i.e. black lips, nose and pads.
The blue eyed white lions are often seen to be scratching, have sunburn and display crusting in exposed areas devoid of hair (such as the inner ears, nasal structures where hair is sparse and jowls.) On this basis, I suspected that these lions could possibly be Albinos (reduction in multiple types of pigmentation) and not just leucistic (partial loss of pigmentation), as they have historically been described.
Dr Desire Dalton of Pretoria Zoo did a study on the genetics of our lions, looking specifically at nuclear DNA sequencing of the Tyrocinase gene (responsbile for Albinism), which showed that our white lions did not have this mutation.
Further, histo-pathological analysis of the eyes of both normal, brown-eyed white lions and blue- eyed white lions, by Dr Gonnie Behr at Ampath Laboratories, revealed a reduced, but not absent melanin (pigmentation) concentration in the blue-eyed compared to the normal, brown- eyed lions.
Therefore, these Lions are not Albinos.
Dr Dalton has isolated a white gene, which is a recessive gene for white lions, and which only expresses itself if this gene is inherited from both parents.
The reason for some white Lions having blue eyes and others brown eyes; with pink or black mucous membranes, is a result of differing expressions of this recessive gene in different individuals. The white lions of the Timbavati are thus not Albinos, neither are they leucistic and they certainly are not a separate sub species, as some would believe.
Of the 22 lion samples analysed it was found that there was a 28% carrier rate of the white gene in the general lion population and a 19% carrier rate of the white gene in the phenotypically normal tawny lion population.
– Written by Dr. Graeme Naylor (Timbavati Private Nature Reserve Member)