There are at least 2 reasons why cheetahs reproduced poorly, which is an added reason why they are vulnerable to extinction in the wild. There has been an approximate 50% decline in population numbers over the past four decades.
Inbreeding
The first reason is inbreeding due to mating between close relatives. There have been two incidents in the cheetah’s history which reduced genetic diversity. The first took place about 100,000 years ago when cheetahs migrated from North America to Asia and onto South Africa. And the second occurred between 10,000 and 15,000 years ago. At that time there was a sharp decline in the number of cheetahs resulting in inbreeding. Numbers are declining nowadays which further increases inbreeding depression.
A study published in 19831 analysed the seminal quality in the South African cheetah and compared it to that of the domestic cat. They collected 40 semen samples from 18 cheetahs. There was no difference between the seminal quality in cheetahs living in the Transvaal or Namibia. The spermatozoa concentration was 14.5 x 106 spermatozoa/ml. The percent motility was 54% compared to domestic cats at 77% motility. “Motility” refers to the ability of sperm to move. They decided, also, that the seminal quality of cheetahs was poor as it contained 71% morphologically abnormal spermatozoa compared to 29.1% abnormal spermatozoal forms in the domestic cat. “Morphologically” means in terms of appearance and function.
They concluded that the “seminal characteristics” in the cheetah “are markedly inferior compared to the domestic cat”. They put this down to inbreeding or in their words “it appears likely that spermatozoal abnormalities are a genetic consequence of genomic homozygosity characteristic of this endangered species”.
RELATED: Inbreeding of wild cats can lead to extinctions in the wild due to unviable population sizes
Global warming
The second reason that I can think of and which I have researched is that global warming is affecting the reproduction of the cheetah. The Guardian newspaper tells us that the world’s fastest animal “has developed abnormal coils in it sperm as a result of warmer temperatures.”
And this is causing the African cheetah to lose its ability to reproduce. And warmer temperatures are also affecting this cat’s feeding habits. Risky Agwanda, head of mammalogy at the National Museum of Kenya said: “Climate change has contributed to defects in cheetah sperm. Many have abnormal coils, low sperm counts, as well as extremely low testosterone levels. Changing climate has made the survival of the gazelle difficult and as a result, the cheetah has had to switch to other diets, also affecting its ability to reproduce effectively.”
He confirmed what the study confirmed above that the cheetah has a sperm count 10 times lower than the domestic cat.
It is actually well known that the cheetah is inbred and inbreeding causes inbreeding depression to use cat fancy language. It isn’t just a sperm count which is depressed it is the health of the animals in general as it affects such aspects of the anatomy as the immune system making it less effective.
RELATED: Signs of Cat Inbreeding.
1. The study is called: Unique Seminal Quality in the South African Cheetah and a Comparative Evaluation in the Domestic Cat. It is published on academic.oup.com.
Below are some more articles on the cheetah.
