Garden team leader Alan Matchett said yesterday that staff had found torn-up aluminium beer cans and a tampon inside the birds' enclosure during the past six weeks.
Mr Matchett said the objects were not only ‘‘bizarre'' but could be ‘‘totally fatal to the birds''.
‘‘If they picked it up and swallowed it they are history. And the keas, being particularly inquisitive, playful birds, they will play with those sorts of things.''
Staff had also found bottles and syringes around the aviary and in the car park in the upper garden.
Increasingly, people were drinking alcohol in the gardens not just at night but during the day.
Mr Matchett told the Dunedin City Council's community development committee staff were investigating the installation of security cameras at the aviary.
