Focus on the outside chances

Outside protected areas, the world’s smallest penguin is in trouble. In Oamaru, where conservation work supports two flourishing sanctuaries for little penguins, research is under way to learn whether  chicks hatched outside sanctuaries measure up to their protected counterparts. Hamish MacLean finds out more.

While the number of little penguins along Oamaru’s coast is unknown, it is estimated more than 1200 little penguins live at Oamaru Harbour alone.

Keeping little penguins free from human disturbance and predators has helped the larger of the two protected colonies in Oamaru grow at an average of 9% a year — and yet the native birds are listed as "at risk — declining" by the Department of Conservation.

Importantly, the recovery of little penguins in New Zealand is understood to depend on conservation efforts.

A key factor in the survival rate of a breeding pair’s young is the weight a little penguin chick reaches before it fledges, at eight weeks, when it leaves its nest to spend about six months away from the colony.

Oamaru Blue Penguin Colony science and environmental manager Dr Philippa Agnew says results from statistical modelling show that, to a point, the heavier the chick is when it fledges, the better its chances of surviving its first time away from its parents.

Now, armed with that knowledge, University of Otago master’s student Shannon Ritter has begun monitoring chicks that have hatched outside the harbour’s two main colonies.

Her work could provide insight into the ongoing conservation work in Oamaru.

"She’s trying to get a gauge of the potential impact of disturbance — those birds [outside protected areas] are going to be more disturbed than here," Dr Agnew said.

An estimated 1020 little penguins inhabit either the Oamaru Blue Penguin Colony’s Cape Wanbrow colony, at a former quarry site (where 416 breeding individuals were recorded this year), or the colony at the Oamaru Creek Penguin Reserve (255), but up to 200 birds are believed to inhabit nesting boxes, burrows, nooks and and crannies in between.

Miss Ritter, who studies wildlife management, has identified 17 accessible nests near the Esplanade and Waterfront Rd, two roads at Oamaru Harbour which more or less connect the two large colonies.

Over the past seven weeks she has begun the same monitoring work that has long occurred at the two protected sites.

Miss Ritter will monitor the unprotected nests until February.

"Then we’re going to see what the growth rate of the nests are, as well as the final fledging weights, to compare them to these ones back here [at the Cape Wanbrow colony]," Miss Ritter said.

"We went out one day, followed poop, followed where we knew some were, and just kind of started looking under things as well.

"The first day that we went out, we found a lot more nests than the 17, but they’re under rocks, they’re under concrete, there’s no physical way to get to them — there are a lot more nests out there."

A "good majority" of the nests in her research were still found in nesting boxes.

Nests were under sheds at the harbour, but they were also found in nesting boxes at the North Otago Yacht and Power Boat Club boat yard where birds have been known to nest, and at nesting boxes at the McKeown Group Ltd yard.

The research Miss Ritter is undertaking could help to show the protection provided by the Oamaru Blue Penguin Colony "is helping grow the penguin numbers".

Dr Agnew says she believes, despite overall national trends, outside the protected areas at Oamaru Harbour the number of birds at the harbour was either steady or increasing.

"And it might be an influence from these two colonies.

"We often find marked birds outside of the colony. They’ll fledge from here and then go and breed down the road."

But another factor was the community’s attitude towards the birds — the respect penguins were given, including people keeping dogs on a lead in the harbour area and giving the birds space.

"The majority of people are good. But we will see, and we see it on Facebook as well, photos of birds obviously cornered, people shining lights, or taking photos with flash, or whatever — it does still happen. There’s not going to be any way to stop that completely."

Dr Agnew says she hopes the work Miss Ritter has started will continue next year, and nests outside the protected areas will be checked every week — "the way we do here".

"But the reality is we just haven’t been able to in the past."

Similarly, a survey of bird numbers along Oamaru’s coast would be informative as it has not been done since Australian seabird and shorebird ecology specialist Peter Dann, research manager at Phillip Island Nature Park, surveyed the area in the early 1990s.

But whatever their number, little penguins are a prominent feature of Oamaru.

"We all know that there are birds everywhere around the town," Dr Agnew said.

hamish.maclean@odt.co.nz