
To move critically endangered black rhinos away from poaching hotspots, conservationists sometimes airlift them upside down. While it might look uncomfortable, a recent study has revealed that this practice is better for rhino health than lying them down on stretchers.
Scroll through the gallery to learn more about upside-down rhino translocation.
Scroll through the gallery to learn more about upside-down rhino translocation.

Robin Radcliffe (left) and his team from Cornell University College of Veterinary Medicine suspended 12 black rhinos upside down to monitor the impact on their health. They were surprised to find that rhinos have higher blood oxygen levels when upside down, compared to lying on their side.

This is good news for conservationists, as lying on a stretcher is a more costly, difficult and time-consuming way to move rhinos by air.

Strapping the ropes to the rhino's legs for an upside-down airlift translocation takes just minutes, says Radcliffe -- much faster than the alternative stretcher method.

But the most common way to move rhinos is still by truck. Jacques Flamand (pictured) says airlifts are only used to remove rhinos from remote areas. Once they're in an accessible location, the rest of the journey will be made by road.

Whether moving by road or air, the rhino needs to be sedated. A small helicopter darts the rhino with a tranquilizer that's 1,000 times stronger than morphine.

If being moved by road, the rhino -- heavily sedated, but still standing -- is guided into a crate for road transport. It's a lengthy process that involves a lot of rangers.

But moving rhinos isn't without risks. The potent tranquilizer already reduces blood oxygen levels -- which is why it's so important to find out which flight position is better for breathing.

Once sedated, the rhino is fitted with a radio transmitter chip, so conservationists can monitor its welfare at its new location.

Rhinos are moved to protect them from poaching and to diversify the gene pool, so that closely related animals don't breed with each other.

Black rhinos were nearly hunted to extinction, with numbers falling below 2,400 in the 1990s. Since then, careful conservation efforts have seen the population more than double.

Africa is home to two rhino species. The white rhino (pictured) has a bigger population than the black rhino, with around 18,000 remaining in the wild. While white rhinos can also be transported upside down, they are nearly twice as heavy as black rhinos so they are airlifted less often.

Using airlifts to move rhinos enables access to remote areas that are difficult to reach by road, like Namibia's northern Kunene region. The region lost its black rhino population to poaching about 25 years ago, says Radcliffe -- but Namibia's first rhino airlift enabled the animal to return.

Namibia's government-initiated community conservancy program makes local people custodians of wildlife. This helps create jobs and tourism opportunities, as well as providing the rhinos with more space and better protection.

While only one airlift translocation has taken place in Namibia, conservationist Jacques Flamand (pictured, foreground) says in South Africa, a few black rhinos are airlifted each year.

In 2015, one of the biggest rhino relocation projects to date moved 100 rhinos from South Africa to Botswana, using a mix of road and helicopter transport. After a 24-hour journey, the rhinos were unloaded at their new home in the Okavango Delta.