'Drunk' parrots can't stand up

Parrots in Australia's Northern Territory are appearing a little wobbly on their legs, showing signs of being drunk and even falling off of trees leaving wildlife experts puzzled and alarmed.

The mystery illness targeting the exotic bird species has found many of them staggering around and in some cases, even passed-out, around the city of Darwin.

Displaying almost human-like behaviour, the birds affected by the illness are often cranky and in need of a good rest before sobering up.

"They certainly appeared to be hungover for quite a long time and have a headache and seem quiet disoriented," said Ark Animal Hospital veterinarian Stephen Cutter.

Darwin's Ark Animal Hospital has been treating the birds affected by the mystery illness and it is caring for about 30 birds at a time. About eight arriving each day after being scooped up from lawns and roadsides.

"They stagger around, they don't have quite the same co-ordination, a bit like someone who has had too much to drink," said Veterinary nurse, Lisa Hansen.

No one appears to know what is causing the ailment.