Cheetahs (Acinonyx jubatus) are remarkable predators that are known for their incredible speed and agility. They can hit top speeds up to 60-70mph, all thanks to their aerodynamic bodies, long legs, flexible spine and semi retractable claws to help with traction. The name Cheetah comes from the Sanskrit word “chitraka”, which means “the spotted one”.
Female cheetahs are usually solitary and males live in small groups of other male siblings called ‘coalitions’. Socialisation only occurs during breeding and the female raises the offspring on her own. A female cheetahs gestation is up to 3 months and can have a litter of 2- 6 cubs. When the cubs are around 6 months of age the mother will start teaching them to hunt and avoid predators such as lions and hyenas. They remain under the watchful eye of their mother for around 18 months. Unfortunately, 70% of cubs do not survive due to being killed by predators. Cub mortality can be up to 90% in non-protected areas. When the mother leaves her cubs to hunt, they are at their most vulnerable to predation. The average lifespan of a wild cheetah can be up to 12 years of age. However, the average for a male cheetah is around 8 years due to territorial conflicts with other males. Adult mortality is a huge contributing factor for the slow population growth of the species.
Cheetahs are listed as ‘Vulnerable’ by the International Union for the Conservation of Nature (IUCN). They face extinction pressure as their population size decreases, a result of climate change, hunting by humans, and habitat loss. Cheetahs also have a low reproductive success, therefore they are unable to increase their population size. The reduction in numbers and fragmented distribution of populations add to the urgency to conserve this species.
Historical events
This is not the only time cheetahs have faced and remarkably recovered from the threat of extinction. Genetic analysis suggests wild cheetahs have survived two historical genetic bottlenecks that dramatically reduced their population size. The first thought to be around 100,000 years ago, when cheetahs expanded their range across Asia, Europe and Africa. These vast distances isolated the populations, they could not breed and this saw the first reduction of their gene pool and loss of genetic diversity. At the end of the last Ice we around 10,000 to 12,000 years ago, a worldwide extinction event took place, and many large mammal species where wiped out. This was thought to be the second genetic bottleneck. The historical range of the Cheetah was dramatically reduced from North America and Europe, to only Asian and African Cheetah populations remaining after the mass extinction. At the end of the 19th century an estimation of 100,000 Cheetahs remained in Africa, the Middle East and other parts of Asia. Today, scientists have estimated there to be around 8,000 cheetahs in the wild across Africa and fewer than 50 Asian cheetahs left in the world. These numbers are still on the decline.
What is a genetic bottleneck?
A genetic bottleneck is a sharp reduction in a size of a population. Just think of a bottle full of beads, each representing a gene. As the bottle narrows towards the top, not many beads (‘genes’) can pass through. The genetic bottle neck limits the genetic diversity in a species. A small population size, with little genetic diversity will inbreed and show a overrepresentation of genes. Over represented genes come with their own problems, causing mutations that have a evolutionary disadvantage. These can be passed down through each generation and each offspring showing a reduction in the diversity of their genetic make up. The term ‘inbreed depression’ is used to describe the reduction in their genetic variation, leading them susceptible to physiological and reproductive deterioration.
Image Source : By Gabi Slizewska – ‘Causes of Bottlenecking’
Cheetahs of today
The impact of these historical events, even thousands of years later, can be seen in our Cheetahs today. Their genetic viability is low and inbreeding still occurs. Cheetahs are struggling to adapt to the environmental pressures and overcome diseases. Cheetahs now have less then 5% of the health gene variation seen in most of today’s living species. The variation is lower then other well known species with poor genetic diversity including the Tasmanian devils, Virunga gorillas, Amur tigers and even our highly inbred domestic cats and dogs.
Only time will tell if Cheetahs can once again defy the odds against them and survive this genetic bottleneck. Humans must do everything in their power to reduce the threats these courageous predators face. Their story isn’t over, but we must help to secure a healthy future for our Cheetahs.
