A juvenile little blue penguin has been spotted on the slipway at Moncks Bay, near Sumner in Christchurch.

Billy just wants his mum to come back, and he doesn't want to meet your dog.

The baby penguin was spotted on the slipway at Moncks Bay, near Sumner in Christchurch, about 1.30pm on Thursday.

The critter, which appears to be a juvenile little penguin, was accompanied by a cardboard sign asking to leave him alone.

JEFF MEIN SMITH The little blue penguin is an endangered New Zealand-native species.

"I'm waiting for my mum to come back," it reads.

"DOC knows I'm here. Please leave me alone. Keep your dog away."

JEFF MEIN SMITH A baby little blue penguin has been spotted on the beach at Moncks Bay, near Sumner in Christchurch.

It was signed of with thanks from "Billy the baby blue penguin".

If Billy is waiting for his mum, however, he may be out of luck. Department of Conservation (DOC) senior ranger Anita Spencer said it appeared the chick had already fledged.

A ranger was on her way to pick Billy up about 4.30pm, she said.

JEFF MEIN SMITH "Keep your dog away" from Billy, the sign warns.

"It's unusual for a blue penguin to be out in the open on the beach during the day. Normally they are at sea or in burrows during the day," Spencer said.

"[Billy] will be taken to the Christchurch penguin rehabilitation centre, where it will be assessed and cared for."

Jeff Mein Smith was cycling past about 1.30pm when he spotted a group gathered around the penguin.

He rushed home to get his camera and returned to find a couple had made a sign and contacted DOC.

Locals had formed "a little penguin protection patrol" to ensure the bird was kept safe, Mein Smith said.

"Apparently some people let their dogs chase it initially."

Spencer said DOC's advice was to give penguins and other coastal wildlife plenty of space and keep dogs away and under control at all times.

She said it was "good to see people looking out for our coastal wildlife" with the sign.

According to DOC's website, the little penguin – also known as the kororā – is the world's smallest penguin.

It is native to New Zealand and the species is at risk.

Kororā grow to just over 25 centimetres tall and weigh about 1 kilogram.

The birds are rarely seen on land and generally only come ashore under the cover of darkness.

Its main threats are dogs, predation and being killed on roads.

Adult kororā come ashore to moult during November and March. During that time, which can last about two weeks, the penguins are especially vulnerable as they cannot swim.

The penguins usually come ashore between May and June to prepare nests, can waddle up to 1.5km from the sea and climb 300 metres to find the perfect nest site. According to the Australian Penguin Foundation website, the gestation period is about 35 days.