The ACT government is warning people visiting the Lower Cotter Catchment or Pierces Creek State Forest to be aware of one male emu that is believed to have chased two families enjoying their picnics a month ago and two more cyclists on Sunday.

One Canberra man recorded the emu chasing a cyclist who was riding along Paddys River Road, near the Cotter River, moments after he was also charged by the animal.

"I was riding down through the Cotter where the recreational area is and spotted two emus on the side of the road," Chris Wilson said.

"I had never seen any emus outside of captivity so I stopped to turn my bike around and went a bit closer towards them to try and get a photo and one started running for me."

It was then that the flightless bird went into full protection mode - it ruffed its feathers, made a drumming noise with its throat and extended its neck up as far as possible.

"It did all these things like it's trying to intimidate you," Mr Wilson said.

"I was on my bike facing it so I had to turn around and when I got about five metres away to a distance it was comfortable with it just stopped and turned around."

A few minutes later he saw another cyclist, who he had earlier warned about the emus when he first rode past, also stop to take a photo.

Mr Wilson quickly took his iPhone out and recorded the emu chase the second cyclist.

Luckily, both cyclists escaped uninjured.

Mr Wilson was "startled" but understanding of the situation as he assumed the emu was protecting its young.

"All I wanted was a happy snap of the emus beside the road. But it was great to see that wildlife you don't tend to see it unless it is in captivity."

Ranger in charge at the Murrimbidgee, Shelley Swain, said it was the first year Access Canberra had received complaints about emus chasing people.

She believed it was one particularly protective male emu who could have been experiencing his first breeding season.

In light of the recent reports, she said Access Canberra will erect signage along the Cotter warning people not to approach the emu.

"The best thing to do would be to gently walk away because they're just protecting their young and once they realise the threat is gone they will typically stop chasing," she said.

"We are in breeding season now so people shouldn't feed them because as soon as we see people lure them into food they will keep coming down for it and that's when they start that behaviour."​

While it is the first year any such incidents have been reported in the ACT, it's a different case elsewhere in Australia.

Last year, a man in his 50s copped a 25 centimetre cut to his left forearm when an emu got spooked and lashed out near Maryborough in Queensland.

It seems Canberrans can add 'emu' to the list of animals they should be wary of when roaming the bush capital.

In August, Kerry Evans suffered more than 20 bites and lacerations across her body after she was attacked by a large wombat while walking her dogs in a suburban street in Banks, in south Canberra.

A few years earlier, ACT Municipal Services Minister Shane Rattenbury escaped with some gashes on one leg and bruising on the other after being attacked by a kangaroo on his morning run.

People who experience or witness wild animal attacks are urged to contact Access Canberra on 13 22 81.