Student craze for swigging beer in trees until you drop – shedding litter and worse – riles New Zealand council

The wider population of Dunedin have long tolerated the bibulous habits of the many students in the city. But that patience is being strained by the emergence of a bizarre new branch of drinking game, according to reports from the southern New Zealand city.

Called possum, the game has quite simple rules: you sit in a tree and drink until you fall out of it.

According to a report in the Otago Daily Times, staff at the city's botanic gardens raised the alarm after noticing "an increase in possum" activity.

The game has caused various concerns, according to Alan Matchett, team leader of the gardens and cemeteries department of Dunedin city council.

The worries include "food scraps, broken bottles and vomit left behind, the potential for someone to get injured falling from a tree, and the effect on other users of the gardens".

Additionally there is the impact on the trees. "Damage could be caused to trees, some of which are classed as heritage trees and are more than 100 years old."

The online Urban Dictionary defines possum as a "drinking game in which players have to sit in a tree, like possums, and consume a pack of 24 beers [typically 350ml units in New Zealand] until they fall out of the tree from drunkenness".

Real possums can be seen as a pest in New Zealand, because of the damage they can do to native trees and other wildlife. With an estimated 30m of the human-introduced marsupials in the country, they outnumber the human population by about seven to one.

Possum is "a variation on a theme of drinking games that require hanging out in random places drinking heavily", explained Joe Stockman, editor of the Dunedin student paper Critic. "It is the same thing every year down here – new students, think it's original, all been done before, ODT [Otago Daily Times] plays along and pretends it's a new problem."

A university spokesman said Possum players could expect to be reprimanded if caught. The few tree-drinkers apprehended to date had been "required to clean up their litter and to meet with the proctor for disciplinary action".