A selection of headlines from stories in the news. They use English in a way that you might think is intended to confuse but it’s all perfectly clear to the native speaker.
The story “Are they bonkers?” in the Daily Mail is about a council that has had all the conkers (the inedible nut-like seed of the horse chestnut) removed from a tree. The extreme action was taken because some children were throwing branches into the tree to dislodge the conkers (an age old tradition for any game of “Conkers“). Unfortunately a girl was injured by one of these branches, so the poor old blameless tree was denuded of its fruit.
They obviously used “bonkers” because it rhymes with “conkers”. You call someone bonkers when they are behaving in an irrational way, so I would say, “Yes, they are bonkers”.