A population crisis of Sumatran rhinos is leading scientists at the Cincinnati Zoo to take a drastic step.

The zoo will attempt to breed their lone female Sumatran rhino with her little brother, reports the Associated Press.

The potential father, 6-year-old Harapan, has been brought back from the Los Angeles Zoo and will soon be mated with his biological sister — 8-year-old Suci.

Conservationists say that they're taking the drastic step of mating siblings because the population of Sumatran rhinos has plummeted in recent decades.

"We absolutely need more calves for the population as a whole; we have to produce as many as we can as quickly as we can," Terri Roth, who heads the zoo’s Center for Research of Endangered Wildlife, told AP.

"The population is in sharp decline and there’s a lot of urgency around getting her pregnant."

Conservationists concluded in April that fewer than 100 of the two-horned rhino species are thought to be left in their native southeast Asia.

According to experts with the International Union for Conservation of Nature, the Sumatran rhino is dangerously endangered.

Their native habitat's proximity to China has meant that the rhino population was "decimated" by high demand for the horn in traditional Chinese medicine.

The rhino is also facing habitat destruction as a result of of palm oil production, logging, and human encroachment.

More from GlobalPost: Persian leopards born in Russia first in 50 years

Critics of inbreeding say that the risks do not outweigh the benefits of any new rhino calves.

Inbred rhinos are more prone to genetic problems and are less likely to survive in the wild, reports AP.

"We don’t like to do it, and long term, we really don’t like to do it," Roth said. "When your species is almost gone, you just need animals and that matters more than genes right now — these are two of the youngest, healthiest animals in the population."

To get the potential couple ready for breeding, conservationists will monitor Harapan’s testosterone levels and use ultrasound to check when Suci is ovulating.

If the breeding is successful, the zoo will welcome their fourth Sumatran rhino baby in about 16 months.