For over three decades, a unique and vital insurance policy for the world's fastest land animal has been quietly growing in the heart of Namibia. American zoologist Dr Laurie Marker has spent the last 35 years meticulously collecting and storing cheetah sperm, creating a genetic 'frozen zoo' she fervently hopes conservationists will never need to use.
A 'Frozen Zoo' for a Worst-Case Scenario
Dr Marker, a foremost expert on cheetahs, founded the Cheetah Conservation Fund in the southern African nation. Since 1990, she has been building a repository of genetic material at her research centre near Otjiwarongo. This sperm bank is designed for a dire emergency, a final safeguard should the iconic big cat be pushed to the brink of extinction. "You don’t do anything with it unless until it’s needed," Marker explained. "And we never want to get to that point."
The urgency behind this project is starkly clear. As World Cheetah Day is marked, conservationists report that fewer than 7,000 cheetahs remain in the wild—a number comparable to the critically endangered black rhino. These animals are scattered across roughly 33 fragmented populations, primarily in Africa, with most groups containing fewer than 100 individuals.
The Threats Shrinking Genetic Diversity
The sleek cats, capable of speeds up to 70 miles per hour (112 km/h), face a triple threat: habitat loss, conflict with humans, and the illegal wildlife trade. This has driven them from 90% of their historical range, with global wild numbers plummeting by 80% in the last 50 years.
This isolation creates a critical genetic crisis. Small, separated groups are forced to inbreed, shrinking the gene pool—a problem scientists believe began when cheetahs narrowly escaped extinction at the end of the last ice age 10,000-12,000 years ago. Compounding this, cheetahs naturally have a high rate of 70-80% abnormal sperm. "The lack of genetic diversity... mean they might need help in the future," Marker stated. "And so, a sperm bank makes perfect sense, right?"
A Conservation Tactic of Last Resort
Storing sperm is an established, if desperate, conservation tool used for species from elephants to rhinos. Its value is exemplified in the battle to save the northern white rhino, where only two infertile females remain. Their sole hope lies in artificial reproduction using frozen sperm collected years ago.
Marker's team does not actively chase cheetahs for samples. Instead, they collect opportunistically, often when called to help cats injured or captured by Namibian farmers who view them as livestock threats. Samples are also taken from deceased animals. "Every cheetah is actually a unique mix of a very small number of genes. We will try to bank every animal we possibly can," she said.
The samples from approximately 400 cheetahs are stored in liquid nitrogen at ultralow temperatures. Currently, the first line of defence would be the 1,800 cats in zoos worldwide, but cheetahs breed poorly in captivity. Should extinction loom, the sperm bank, like that for the northern white rhino, would become the final option. Without this genetic repository, Marker warns, "we’re not going to have much of a chance."
