If you ever find yourself looking into the skies above the African savannah and see a bewildered rhinoceros dangling upside down from a helicopter, try not to be alarmed. Although it may look a tad undignified, this method of transportation may actually be the safest way to move black rhinos from location to location.

Black rhinos, a critically endangered species native to eastern and southern Africa, are often moved around as part of the critical conservation efforts to save the animals from extinction. Conservationists distribute individuals across habitats to keep the gene pool mixed and to keep rhinos safe from poachers. Although trucks are the first option, helicopters are often used to airlift the animals to rural hard-to-reach areas away from human habitation.

A typical approach to airlifting involves placing the rhino on its side on a stretcher. However, a new study in the Journal of Wildlife Diseases argues that suspending them upside down by their feet may be a healthier and less stressful way to do so. 

Conservationists at Cornell University's College of Veterinary Medicine collaborated with the Namibian Ministry of Environment and Tourism to study how 12 black rhinos reacted to being anesthetized in two different positions: hanging by their feet from a crane to mimic the effects of air transport or lying on their sides. After being tranquilized with a potent opioid and held in one of the two positions for 10 minutes, the team tested some of their vital signs to see how their body had reacted to the shock. All 12 rhinos were subjected to both treatments. 

The researchers feared that suspending rhinos upside down would most likely worsen the dangerous effects of these opioids. However, they discovered that the upside rhinos actually fare slightly better than the rhinos that were laying down.

“Hanging rhinos upside down actually improved ventilation (albeit to a small degree) over rhinos lying on their sides,” Dr Robin Radcliffe, study author and senior lecturer in wildlife and conservation medicine, said in a statement. “While this was unexpected, and the margins small, any incremental improvement in physiology helps to enhance safety of black rhinoceros during capture and anesthesia.”

It’s worth pointing out that both methods of airlifting can be a pretty stressful experience for the rhino. In both positions, all rhinos were found to be hypoxemic (lack of oxygen in the blood) and hypercapnic (too much carbon dioxide buildup in the blood), indicating the postures had impacted their pulmonary system. However, for the time being, transporting black rhinos via helicopter is a necessary part of their species' survival.

“Our next step with this research is to extend the time that subject rhinos are suspended upside down to mimic the helicopter-assisted aerial transport of rhinos in the real world,” added Dr Radcliffe. “Now that we know that it’s safe to hang rhinos upside down for short periods of time, we’d like to make sure that longer durations are safe as well.”