Kororā, or little blue penguins, look terrible when they're moulting - but an expert says it's part of their natural lifecycle. Photo: DOC / Brent Tandy
Scruffy, sick-looking penguins turning up on beaches around New Zealand during summer are undergoing part of their natural life cycle and nothing to worry about, a bird expert says.
However, the birds - especially kororā or little blue penguins - are extra vulnerable to dogs at this time of year, so the Department of Conservation is pleading with beachgoers to keep their pets on a leash in areas where penguins nest.
DOC ecology advisor Bruce McKinlay said adult kororā came ashore between November and March to shed their old feathers and grow a new waterproof coat.
While kororā could turn up anywhere along the New Zealand coast to moult, species such as crested penguins or tawaki could be spotted coming ashore in Southland and Otago.
The process of moulting and regrowing feathers took two to three weeks.
McKinlay said DOC often fielded calls at this time of year from people concerned about scruffy, sickly-looking penguins.
"But they're almost always moulting," he said.
"While it doesn't look pretty, this is a natural part of the bird's lifecycle. When you grow a feather, it's only good for about a year, then it loses its structure. In the case of penguins they also need to be waterproof," McKinlay said.
"So the birds shed them all, they then convert fat into new feathers, which they push out through their skin and create a new coat.
"While they're doing it they're utterly miserable. They've got thousands of pinpricks going through their skin, they can't go to sea so they're starving, and they basically look like a mess," he said.
"But it's part of the normal annual cycle for penguins, and they have to do it. It's part of their biology. The best thing to do is leave them be, and ensure they're undisturbed during their moult."
However, penguins were unable to swim while they were moulting, which made them extra vulnerable to dog attacks.
As well as giving penguins plenty of space, he urged beachgoers to warn other people nearby of the birds' location, and to keep dogs away from nests and on a lead around penguin areas.
Anyone who saw unleashed dogs running around on the beach, or people harassing penguins, should call 0800 DOC HOT.
People could also call the 24-hour DOC hotline if they were worried about a penguin being in an unsafe place, McKinlay said.
Just last week DOC staff and locals were shocked when two boys were seen kicking protected oystercatcher chicks at Mangawhai in Northland.
One chick died while the other was rescued by locals and returned to the beach once it had recovered.