A robot has infiltrated a troop of mountain gorillas in Uganda, allowing producers of a nature TV series to capture rare footage of them singing, humming and farting during meal times.
In PBS's Nature: Spy in the Wild 2, the show's creators use robotic lookalikes to avoid the suspicion of animals they film. This allows them to capture the genuine behaviours of animals unaware they're being recorded.
In this instance, a baby gorilla robot was accepted after being inspected by the troop's alpha male.
The robot was programmed to avert its gaze while the gorilla looked into its eyes, leading it to deem that it wasn't a threat and allow it to join the troop.
Once it had infiltrated the troop, the robot was able to film a range of gorilla behaviours rarely seen when humans are present.
Among these were persistent and sustained bouts of flatulence during meal times, fuelled by the incredible 18kg of plant material they eat every day.
But perhaps more surprising was the singing and humming the robot gorilla captured. While scientists noted the phenomenon in a 2016 study published in PLOS ONE, it's the first time it's ever successfully been filmed, according to the show's narrator.
The PLOS ONE study also noted that older gorillas hummed and sang more than young gorillas during meals, and that males sang more often than females did.
The full gorilla episode of Nature: Spy in the Wild 2 premiered in the US on April 29.