Koalas Are at Risk of Extinction in Some Parts of Australia. Can Freezing Their Sperm and Eggs Help Save the Iconic Marsupials?

Scientists are preserving the animals’ reproductive cells in liquid nitrogen in a bid to boost genetic diversity in future populations

Sarah Kuta | Daily Correspondent

July 20, 2026 11:00 a.m.

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Koalas are among Australia’s most beloved animals, instantly recognizable by their fluffy ears, button noses and joey-filled pouches. But despite their iconic status, the marsupials are facing mounting threats, including deforestation, bushfires and deadly diseases like chlamydia.

Now, scientists are taking precautionary steps to support future generations of the animals. They’re establishing a dedicated koala sperm and egg bank that they hope will function as a “genetic safety net” for wild populations, according to a July 2 statement from Australia’s University of Queensland, which is spearheading the project.

“We cannot wait until populations are smaller and genetic diversity is harder to recover,” Andres Gambini, a reproductive biologist at the university, says in the statement. “By preserving sperm and eggs today, we are giving future conservation programs more options to protect koalas tomorrow.”

Researchers plan to build up the bank by harvesting sperm and eggs from koalas treated at the Currumbin Wildlife Hospital that later die or are left unable to breed because of trauma or disease. The animals’ reproductive cells will be collected at the hospital, then placed in temperature-monitored boxes and transported to a lab at the University of Queensland.

There, scientists will screen the samples for Chlamydia pecorum, a bacterial species known to infect koalas and cause health problems ranging from blindness to infertility. If they determine that the reproductive cells have “genetic value,” they’ll remove the bacteria from the samples and freeze them in liquid nitrogen, says Steve Johnston, a reproductive biologist at the university whose work contributed to the first koala joey born via artificial insemination, in the statement.

Years from now, scientists will be able to tap into the bank’s frozen deposits to produce koala embryos through artificial insemination and in vitro fertilization.

The method is a common practice used to preserve sex cells from many animals, including humans. “I’ve successfully woken cells up that were frozen in [liquid nitrogen] a couple of decades ago,” Vincent Lynch, a biologist at the University of Buffalo who is not involved with the project, tells Live Science’s Sascha Pare.

Maintaining a diverse gene pool is critical for the species’ survival. Without enough diversity, koalas can be less resilient to diseases, environmental changes and other future threats.

But banking koala sperm and eggs won’t save the species on its own, the researchers say. Instead, they see the bank as one tool in a broader conservation strategy that also includes habitat protection, disease management and prevention, ongoing population monitoring and other actions.

Koala conservation is a complex balancing act in Australia. In some regions, populations are in steep decline. But in others, the animals are so abundant that officials say they exceed what the remaining habitat can sustainably support. 

The species is listed as endangered in the states of New South Wales and Queensland, as well as the Australian Capital Territory, a fact that Michael Pyne, senior veterinarian and general manager at Currumbin Wildlife Hospital, finds “really embarrassing.”

“I often say, ‘If we can’t be bothered to save koalas, what can we be bothered to save?’” Pyne tells the Australian Broadcasting Corporation’s Grace Nakamura.

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Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.