New Zealand is the seabird capital of the world, with twice as many threatened species than any other country. While our seabirds are more threatened than our land birds, far more effort goes into the conservation of a few high-profile land birds than all our seabirds put together.
Wild gannets in courtship at Muriwai. Photo: 123RF
Ornithologist and conservationist Kerry-Jayne Wilson's recently released book, New Zealand Seabirds: A Natural History, shares her passion for the subject and insights from her 45-year long career.
There are varied definitions of what constitutes a seabird - for Wilson, it's any bird that takes most or all of its food at sea. However, she doesn't follow this strictly, as it wouldn't include what most people think of when they hear the word seabird - our native seagulls, which find most of their food on land and in rivers and estuaries. Wilson considers there to be 84 species of seabird native to New Zealand, which is more than almost any country in the world.
The most threatened is the New Zealand fairy tern, which is down to about 40 individual birds and only about 12 nesting pairs. They nest at this time of year, on beaches north of Auckland - which unfortunately coincides with summer crowds using those same beaches.
Wilson says the best way to protect these threatened birds, is for people to take care around them and be aware of their existence.
A New Zealand fairy tern. Photo: Oscar Thomas
"There are a lot of people who are trying to protect the birds who are doing a fantastic job at roping off the nesting areas, who are doing a fantastic job at alerting people to the presence of these birds," she says.
"But it's going to take beach-users caring for the birds, caring that they're there, knowing that they're there first of all and then giving them space. If we can give them space, they will breed, they will do ok."
As an undergraduate student, Wilson started her career on the Snares Islands, south of New Zealand, as an assistant to the photographer and ornithologist Dr John Warham over the summer of 1969-1970. While she says she didn't know much about seabirds before taking on the assignment, they soon became a lifelong passion.
Kerry-Jayne Wilson at work. Photo: RNZ/Supplied?
In fact, she says her first night on the Snares was when her book started writing itself.
"The Snares were amazing," she says. "Each evening the sky went back, with just clouds of sooty shearwaters circling around and landing there. A burrow of sooty shearwaters every square metre on the forest floor. There were hundreds - no thousands - of penguins, diving petrels, prions, albatrosses.
"I stood on the cliffs at the Snares Islands and wondered where these birds went, why were there so many of them, how did they find food, where did they find food, how did they navigate in the open ocean, and I guess those questions have nagged me ever since."
Salvin's albatrosses are small albatrosses which breed only at the Bounty Islands and on the Western Chain near the Snares. Photo: RNZ / Alison Ballance
While she says great progress has been made in answering some of these questions, for some others we know little more than was known 50 years ago.
One particularly topical unknown is the effect climate change has had and will continue to have on seabird species.
Wilson says that rockhopper penguins numbers on Campbell Island, south of New Zealand, have declined by 94 percent since the 1940s. While it was found that this correlates with sea surface warming over that period, she says the sea surface has warmed by hardly anything that's measurable.
She says the concern is not in average temperature increases over time, but rather abnormally warm years, which have increased considerably.
Rockhoppers at Campbell Island. Photo: Supplied
"Part of our thinking is the increase in unusually warm years at sea are going to reduce the amount of food available to many seabird species. Now there'll also be some winners, but we're not sure who they will be."
In terms of future conservation efforts, Wilson says she would like to see an increase in sanctuary islands, as well as better biosecurity on these islands. However, efforts also need to be made to increase the number of seabirds using sanctuary islands, which can be more difficult - as most seabirds are very faithful to the islands where they were hatched.
"To increase the spread of birds over more islands, and to have our eggs in more baskets, so to speak, we need to move chicks from island to island to establish new colonies," she says.
"So we have to move them to the island we would like them to come back to and feed them for those few weeks, which is incredibly time consuming, it's very labour intensive and the rewards you get take time and small rewards for lots of effort.
"Some species are confined to just one or two or three islands, so if predators get to those islands we could lose species almost instantly."
Another important conservation issue is protecting birds from fisheries bycatch.
In the past decade, female Antipodean albatrosses have begun spending long periods in the eastern Pacific, where they are at risk from foreign fishing fleets. Photo: CC BY-NC 2.0 Nik Borrow / Flickr
"Tens of thousands of birds get caught by fisheries bycatch every year. And things like Antipodean albatrosses are declining because of fisheries bycatch.
"We suspect but we've been unable to show conclusively that a large part of the decline of yellow eyed penguins is due to fisheries bycatch.
"And of course the fishing industry is a very powerful industry, it has a lot more money than we have for protecting of those birds."
While many would think of ocean plastics as being a big threat to our native birds, Wilson says plastics have not been a huge issue so far - but it is a growing concern, as modelling by oceanographers suggests the next major problem for plastics will be the convergence areas in the southern Tasman Sea.
"Now that's where an awful lot of our birds forage," she says. "Due to ocean currents, plastics are accumulating in those zones due to the same ocean currents bringing food in."
And back to questions with unknown answers, Wilson says how seabirds navigate the world mostly remains a mystery, even to the experts in the field.
Sooty shearwaters travel huge distances across the Pacific.The sooty shearwater - which Wilson says is her favourite seabird - travels huge distances over the course of a year, from the ice edge in the Antarctic to the ice edge in the Arctic, and all the way across to the Humboldt current off South America. Photo: Wikimedia Commons
"They know where they are, they know where they're going and we don't know how they do it," Wilson says.
"So we can show that if we put magnetic fields around them it confuses them, we can show that they use scent to some degree, we can show that there's some degree of instinct involved, but we don't know how they navigate.
"In that little brain of theirs is a mental map of the entire Pacific Ocean, knowing which time of year it's good to be at which place. And in the dark they can find their nest and land within a few metres of where their nest is.
"That's one of the mysteries that still intrigues me and no amount of reading I've done convinces me that we know much about their navigation at all."
