Chicago zoo visitors have been told to put their phones away after a distracted gorilla was "jumped" by another giant primate as he stared at a visitor's screen.
The 16-year-old, named Amare, was "rushed" by another gorilla while he was "glued to a cellphone", according to reports.
Amare, who lives at Lincoln Park Zoo, "didn't seem to notice" what was happening, the Chicago Sun Times reports.
Staff at the zoo are now anxious to prevent it happening again, and are making efforts to reduce Amare's screen time.
Stephen Ross, the director of the zoo’s Lester E. Fisher Center for the Study and Conservation of Apes, told the newspaper: "We are growing increasingly concerned that too much of his time is taken looking through people’s photos, we really prefer that he spend much more time with his troop mates learning to be a gorilla."
It is common for gorillas to act in an aggressive way to "show who's boss", but it is feared that Amare could be at a disadvantage if he continues to be transfixed by screens outside his enclosure.
Unfortunately it's been noticed by other humans, with some visitors now trying to get the gorilla's attention using phone screens.
Mr Ross said: “It’s probably a cyclical phenomena, the more he shows interest the more people want to engage in it... It’s something we’ve noticed and have talked about a lot in terms of a strategy to address it."
New rope barriers have been put in place to keep visitors back, and anyone seen showing Amare their phones will get a talking to.
This has led to some improvement, zoo officials say.
Mr Ross told the Chicago Tribune : “Amare is realising that it’s not really worth it for him to sit there in that corner, waiting for someone to come up and show him their phone.”
Studies show excessive screen time in adolescents can lead to physical and mental health issues, and the expert said this is the same for gorillas.
Mr Ross said the reasons for limiting screen time for human and gorilla teens "were not terribly different".
