Oamaru Blue Penguin Colony expansion call

The Oamaru Blue Penguin Colony. Photo: Hamish MacLean

Future-proofing Oamaru's little penguin population could require expanding the Oamaru Blue Penguin Colony footprint.

Oamaru Blue Penguin Colony research scientist Dr Philippa Agnew said at the roughly 1ha tourism colony at the quarry at Cape Wanbrow, 350 nesting boxes supported 189 breeding pairs — and if it was allowed to expand into one-third of the unsealed parking lot behind the colony, 100 more nesting boxes could be added to help bolster the colony's numbers.

Dr Agnew's research identified in 2012 that one of the "major drivers" of the population would be severe storms like the one that hit Oamaru at the end of November.

"But this is the first one that has happened mid-breeding season," Dr Agnew said.

And climate science was predicting an increased frequency and intensity of storms in the future.

So, as the Waitaki District Council planned its 30-year vision for the harbour through its harbourmaster planning process under way, it was important to accommodate growth now.

"We need to build populations that are going to be resilient to these sorts of environmental impacts," Dr Agnew said.

"So, if you've got a larger population that is affected by a storm event and it reduces that survival for the year to three-quarters of what it would normally be, a bigger population obviously has a larger pool of birds [and] if they lose more than normal, the population is still going to be OK.

"There's no sense in building lots of tourism operations or whatever and filling the space and then going 'Oh, no, we haven't got any more room for the birds'."

Dr Agnew said she hoped to expand the colony's footprint in the next couple of years.

In 2015, a major storm reduced adult survival rates from the average of 85%, to just 60%.

But the effects of the November storm would not be known until after the birds moulted in April, when a reliable count could be done.

The colony's parent company, Tourism Waitaki, had asked the council to promote Oamaru as "one of the seabird capitals of the world", yet the population at Oamaru remained "fairly small in the grand scheme of things".

At the tourism colony's neighbouring Oamaru Creek Reserve colony — with 300 nesting boxes and more than 120 breeding pairs — there was potential for some form of tourism operation there as well, Dr Agnew said.

It would not, she said, support the up to 410 visitors a night the Oamaru Blue Penguin Colony hosted though. In Dr Agnew's submission to the Oamaru Harbour masterplan process, she also called for an Otago shag viewing platform and for a webcam, streaming either to the colony's or the council's website, for the rare endemic seabirds nesting on Sumpter Wharf.

hamish.maclean@odt.co.nz