Headline isn't what the article says.

“We disrupted the tradition of the teenager taking care of the young ones,” Martin Boye of the Loro Parque Fundación says.

“They should have been under the watch of their teenage relatives, but there were no teenagers left,” Boye said. “So these calves started doing stupid things, they were not afraid of anything.

“And then they grew up and became adults and when they play now, it’s a little bit more robust.”

So they're adults who grew up without the traditional supervision of the teenagers. Journalism has gotten so bad.