A Brisbane professor conducting the world's first study into meat-eating rainbow lorikeets says he is shocked to discover more species of herbivorous birds are also changing their diets.

In March the ABC revealed a population of rainbow lorikeets were eating meat from a backyard feeding station on a property at Elimbah, north of Brisbane.

Bill Watson, who owns the property, has been feeding chicken mince to wild birds for more than a decade.

In 2007, he discovered the rainbow lorikeets were taking meat, followed by scaly-breasted lorikeets a month ago and just recently, cockatoos.

Griffith University's Professor Darryl Jones said he was astonished three species of birds considered to be herbivores had changed their diets.

"The move for a bird that normally eats pollen and nectar to eating primarily meat is absolutely extraordinary," he said.

"It is of international significance, this is a truly large and major project that we've got on here."

'It seems like the birds are going crazy'

Ornithologists have long thought rainbow lorikeets, cockatoos and scaly-breasted lorikeets ate nectar and pollen taken from native plants and shrubs.

Professor Jones said the birds at Elimbah had changed conventional science.

"Suddenly they're switching from a plant-based diet to a meat-based diet," he said.

"That could have all kinds of implications for birds' health and physiology.

A scaly-breasted lorikeet eats meat from a backyard feeding station on a property at Elimbah, north of Brisbane. September 2015. ( ABC News )

"I'm supposed to be an expert on bird feeding and this is something that I had no idea [about], did not expect, and no one ever told me ... was happening.

"From a research perspective this is [as] absolutely exciting as it gets.

"People from all around the world have contacted me, saying 'what on Earth is going on in Australia?'.

"It seems like the birds are going crazy."

Griffith University's Professor Darryl Jones is conducting the world's first study into meat eating rainbow lorikeets. ( ABC News )

Professor Jones said bird physiologists and veterinarians would take part in the study.

"We hope to find whether this is truly an unnatural or artificial situation or is it just an extension of what is a normal diet," he said.

"And we also really want to find out whether it's a harmful practice because it's (backyard feeding) very widespread.

"If it's harmful for the birds, then everyone needs to know that."

Mr Watson said he would keep feeding the wild birds on his property.

"I'm a bit worried that they might find that I've been doing the wrong thing," he said.

"What if I've been feeding them and doing them damage, although I haven't seen any dead ones laying around.

"If the professor says don't do it, how do I stop them?

"What do you do, stitch up their beak?"

Honours student Rhiann Gillanders, who is assisting Professor Jones with the study, wants to find out what other types of herbivorous birds also eat meat.

"I want to see how common it is and what their behaviour is like when they're given the opportunity to have a high protein diet and I guess what implications that might have," she said.

"There have been a few reported cases of other parrot species, rosellas and things that are choosing to eat meat as well which is really surprising people."

Professor Jones will conduct research at Elimbah, along with 20 backyards in Brisbane where people feed a variety of birds.