Lions of Tanzania (Serengeti, Ngorongoro and others)

[BA0701]

The following post was shared by @Wyld@Heart in another thread, provides us with a wealth of information about the Crater Lions, and the impact that the lack of genetic diversity is having on the population. 

Wyld@Heart's original post:

"There have been, the ones I know of are specific to lions of Ngorongoro where inbreeding is pretty much unavoidable. 

https://conbio.onlinelibrary.wiley.com/d....tb00127.x

https://www.google.com/url?sa=t&source=w...WjFlv8FEj0

I hope the links work. There are also a few others about. Some 'light' reading, haha."


The first link, conbio, is a short informative abstract of a case study written by C. PACKER, A. E. PUSEY, H. ROWLEY, D. A. GILBERT, J. MARTENSON, S. J. O'BRIEN, and the second link is the full study. This study combines information on two subjects I have long been fascinated with, Crater Lions and the impact of inbreeding on the wild lion population. 

The abstract states:

Abstract: Lions in the Ngorongoro Crater, Tanzania, form a small and naturally isolated population. In 1962, the Crater lions suffered an epizootic that reduced the population to nine females and one male. An additional seven males apparently immigrated into the Crater in 1964–1965, but there has been no further immigration into the Crater in the past 25 years. By 1975, the population had recovered to its current level of 75-125 animals. All members of the current Crater population are descended from only 15 founders, and over the years there has been considerable variance in the reproductive success of both sexes. The Crater was probably colonized by lions from the nearby Serengeti ecosystem and the contemporary Crater lion population shows a significant lack of genetic diversity compared to the much larger Serengeti population. The detailed reproductive history of the Crater population was incorporated into a series of stochastic computer simulations that generated distributions of expected allele frequencies under different sets of initial conditions. The simulations suggest that the Crater population may have passed through previous bottlenecks before 1962 but that the level of heterozygosity in the breeding population has been declining since the mid-1970s, regardless of the population's genetic composition in the 1960s. High levels of inbreeding are correlated with increased levels of sperm abnormality in lions and there is evidence that the reproductive performance of the Crater lions has decreased as a result of decreasing heterozygosity. Reply