The potential of a cheetah sperm bank to save the fastest land animal

CAPE TOWN, South Africa For more than three decades, American zoologist Laurie Marker has been preserving cheetah genetic material at a sperm bank in Namibia, aiming for a future where it might never be needed. Yet she acknowledges the possibility that cheetahs, the fastest land animals on Earth, may one day face such severe population decline that artificial reproduction could become essential.

Marker founded the Cheetah Conservation Fund in southern Africa, where the sperm bank serves as a frozen zoo of cheetah specimens, a project she began in 1990. The collection would be used only in extreme circumstances, as the wild cheetah population has sharply decreased over the last 50 years.

This is only for emergencies, Marker said from her research center near Otjiwarongo, Namibia. And we hope we never reach that point.

With less than 7,000 cheetahs remaining in the wild, comparable to the critically endangered black rhino, conservationists marked World Cheetah Day this week. These cats exist in roughly 33 isolated populations, mostly numbering fewer than 100 individuals each, according to Marker. Habitat loss, human conflict, and illegal wildlife trade threaten their survival, while small, fragmented groups are causing a decline in genetic diversity, affecting reproduction.

In the last 50 years, wild cheetah numbers have fallen by 80%, with the species now occupying only 10% of its historical range. Scientists believe cheetahs narrowly survived extinction at the end of the last ice age, which first drastically reduced their genetic diversity. Today, their high rate of abnormal sperm7080%means that preserving genetic material could become critical.

A sperm bank makes perfect sense for them, Marker said.

Using frozen reproductive material is not unique to cheetahs. Conservationists employ similar strategies for elephants, rhinos, antelopes, big cats, and birds. Marker cites the example of the northern white rhino, now functionally extinct with only two females left. Their survival hinges on artificial reproduction using previously frozen sperm, with scientists attempting embryo implantation into southern white rhino surrogates.

Other species have benefited from assisted reproduction, such as black-footed ferrets, which were successfully bred after their wild population in Wyoming dropped to a single group.

Marker collects cheetah sperm opportunistically rather than actively chasing the animals. In Namibia, most cheetahs are at risk from farmers protecting livestock. The conservation team gathers samples when treating or relocating injured or captured animals. Sperm can also be collected from deceased cheetahs.

Every cheetah represents a unique combination of a very small number of genes, Marker said. We aim to preserve as many animals as possible.

Currently, samples from about 400 cheetahs are stored at ultralow temperatures in liquid nitrogen at the Cheetah Conservation Fund laboratory. The research avoids artificial insemination, as captive breeding is not permitted in Namibia. In the event of a population crisis, captive cheetahsroughly 1,800 globallywould be the first line of backup. However, since cheetahs do not reproduce reliably in captivity, the sperm bank may serve as a last resort.

Without it, our chances are very slim, Marker said.

Preserving Cheetah Genetics: A Last Resort for Survival

As the cheetah population continues to decline, the work of Laurie Marker and the Cheetah Conservation Fund takes on increasing importance. With fewer than 7,000 cheetahs remaining in the wild, their survival is under threat due to habitat loss, human-wildlife conflict, and genetic fragmentation. The sperm bank established by Marker in Namibia represents a crucial effort to preserve the species' genetic material, offering a potential lifeline in case of a population collapse. While the frozen zoo aims to serve as an emergency backup, the hope is that it will never need to be used.

The alarming decline in cheetah numbers over the past 50 years, with an 80% decrease in their population, underscores the urgent need for such conservation measures. With cheetahs' genetic diversity already diminished from past bottlenecks, their future looks precarious. The frozen sperm bank could hold the key to ensuring that these fast-running predators don’t vanish entirely. However, as Marker points out, this is a last-resort strategy, one that emphasizes the importance of proactive conservation efforts and habitat restoration.

Although similar strategies have been successful with other endangered species, such as the black-footed ferret and northern white rhino, cheetahs face unique challenges. With most of their population spread across fragmented groups, maintaining genetic diversity through artificial reproduction may prove difficult. The situation requires urgent and continued attention, both from local conservationists and the global community, to ensure that cheetahs remain a viable species on Earth.

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• How a sperm bank for cheetahs might one day save the fastest land animal