Australia - Parrots in Sydney's Royal Botanical Gardens are getting drunk on tree nectar that has fermented in the spring sunshine, it was reported on Friday.

The Sydney Morning Herald said rainbow lorikeets in the central Sydney reserve were staggering around tipsy after eating nectar from the tree "schotia brachypetala", a member of the pea family which began flowering this week.

"It produces a lot of sweet nectar, a nectar that is a sugary juice. If it ferments in the heat of the sun it can produce alcohol," the gardens' curator, Ian Innes told the newspaper.

"The lorikeets get right into it."

Senior veterinarian at Taronga Zoo, Larry Vogelnest, said lorikeets in northern Australia were also known to become intoxicated on fermenting fruit.

"Basically they behave like drunk people, staggering around and unco-ordinated," he told the Herald.