MAMMA penguin tentatively pokes her head through the artificial burrow into the area where she has prepared a nest from the grass in her enclosure at Billabong Zoo Koala and Wildlife Park.

There she ensures her egg is safe before venturing outside for a bit of sustenance. This will be her routine for the 35 days it will take for her baby to hatch.

Head keeper at the zoo, Christy Brown, said the mother penguin will spend most of her time sitting on the egg.

"It's really exciting for all at Billabong as this is the first egg produced by the little penguins," she said. Commonly called fairy penguins the two pairs of little penguins were just a couple of months old when they arrived at the zoo in December, 2012.

"They usually don't breed until age three in the wild but in captivity they can start earlier," Ms Brown said. "The breeding season is June to October so it is very early for them to have produced an egg."

Although numbers of the little penguins are secure Ms Brown said the zoo's breeding program is important for education purposes and the mainland population of the little penguins is threatened.

"There is only one NSW breeding site near Manly and the biggest threat is litter in our ocean."

On the nesting islands offshore they can be under threat from feral dogs and foxes because they can't protect themselves.

"They only weigh about 1 kilogram so it is important we educate school children and their families about the danger to the penguins from rubbish thrown into the ocean."

Unfortunately the public is unable to see this miracle of nature as the staff will take care to disturb mum and her egg as little as possible to avoid her rejecting it or the egg being damaged.