A distressed grey langur monkey was spotted at the top of a transmission tower in Khadiya, a village in the central Indian state of Madhya Pradesh. The monkey had climbed up the tower with a rope tied around its neck. The rope got snagged in something at the top of the tower, leaving the monkey stranded and helpless.
Two days later a team of volunteers from an animal rescue organization arrived on the scene to try to help the monkey break free from the rope and climb down. Local police officer Prashant Tyagi explains that the power supply was cut for over three hours “to help experts rescue the monkey.”
As the volunteers began scaling the tower, the monkey became distressed, struggled, and managed to free itself. Unaware that the men climbing the tower were there to help, the langur perceived them as threats, and in an act of desperation, leapt to the ground.
Original reports claimed that the distance of the fall was 100 feet, but we calculated the fall to be closer to 65 feet. Even from the shorter distance, that is still out of the range of the average langur leap.
“This is a very long jump. However, jumps of 30 to 40 feet between trees are not uncommon, nor are jumps to the ground from 20 to 30 feet,” said Agustín Fuentes, professor of anthropology at Notre Dame, when asked about the video.
Luisa Arnedo, a senior programs officer at National Geographic who got her PhD studying primates, also weighed in on the video. Animals can “jump incredible heights out of stress or desperation,” she says.
“It seems like in this case the animal didn’t have another choice. There were so many people around and then these guys are climbing the tower, the animal doesn’t know they are trying to help, it feels trapped and the only way out is to jump.”
What was surprising was how the monkey landed on its feet and ran away, seemingly unharmed. In a fall from a similar height, a human would have likely snapped a femur or suffered spinal damage. “Langurs have terrifically adapted leaping anatomy and are very good at long jumps and 'bounce' landings”—which you can see in the video, as it meets the ground—“that distributes the impact force," Fuentes says. “Still, the monkey was lucky to land perfectly.”
John David Polk, associate professor at the University of Illinois and expert in biomechanics of locomotion was wary of the health of the monkey. “The adrenaline associated with the escape may have masked a fairly serious injury that might only be recognized later.”
“But let's say, for discussion, that it was not injured,” Polk says. “Langurs have relatively long hind limbs and they are used to using them in fairly flexed postures. The long limbs will allow a long duration of eccentric extensor muscle action at the hip, knee, and ankle that would allow the monkey to slow the tendency of these joints to collapse in flexion when landing.”
This unique anatomy, paired with long stretchy tendons, gives the langur the strength to absorb the powerful forces acting on the joints during impact.
These kinds of situations are difficult to navigate for animal rescue teams. Finding a balance between helping a distressed animal and actually putting the animal in more danger can be hard to do. Luckily in this scenario, the monkey seemed to be fine.