Meet the ten native species that could check out before you do. Dave Hansford looks at why you should give a damn
Photo: Dave Hansford/Origin Natural History Media
Imagine a land without pestilence. A forest in full song. An ocean glittering with silver shoals of fish.
Aotearoa was such a paradise. Some 85 million years ago, it broke away from the primordial landmass of Gondwana before mammals reigned supreme, a lifeboat crewed instead by birds, insects, molluscs and plants. Safe from mammals, suffering only casual predation, many of our birds allowed their wings to wither, adopting a pedestrian life on the forest floor.
But the arrival of the Polynesian fleet delivered disaster. Aboard the explorers’ canoes were kiore, the Polynesian rat—rapacious, keen of smell. The extinctions began immediately.
Much worse was to come. Europeans brought more vermin: ship rats, mice, cats and dogs. They brought rabbits, hares, weasels, stoats, ferrets, pigs, goats and deer. They burned and felled their way through the remaining tracts of forest. A rich, unique bestiary vanished.
The death toll ranks among the world’s worst. In 750 years, half of New Zealand’s vertebrate (backboned) fauna disappeared. At least 51 birds—one-third of our aviary—three frogs, three lizards, a freshwater fish, four plant species, and an unguessable host of invertebrates were gone forever.
You will never see a moa, or a laughing owl. But how about the red-billed gull? That’s right, the one you throw your leftover chips to at the beach. Recent surveys have found that colonies in the outer Hauraki Gulf are in decline, possibly because of warming sea temperatures.
New Zealand’s biodiversity loss has entered an ominous new phase, in which animals we’ve taken for granted—the grey duck, the long-finned eel, the whitebait—are vanishing behind our backs as we labour to save the critically stricken.
Extinction is going mainstream. Pests still stalk our forests, but today our native creatures also have to cope with deadly new agents of destruction: climate change, new diseases, fishing, the dairy boom and biosecurity incursions.
Every day, more native species are sucked closer toward the black hole of extinction.
Nearly half of our 5,819 known species face some degree of risk. Last year, 416 species were added to the Department of Conservation’s threatened species list; 23 became nationally critical, the gravest status. Some 980 species languish in the “data deficient” category—creatures, probably threatened, that we don’t have the resources to study.
As Department of Conservation senior scientist Greg Sherley puts it, “These are Kiwis, just like the rest of us, and they’re going extinct. This is serious shit, and we want to get them back, because they’re important to us. They’re taonga.”
Tuatara
Our very own living relic from a time before dinosaurs, the tuatara is now mostly confined to offshore islands. Its future in the wild hangs by a few degrees Celsius.
The sex of tuatara hatchlings, like that of many reptiles, is determined by the temperature they are incubated at.
Researchers at Wellington’s Victoria University discovered that 21.7°C appears to be a tipping point, where femininity mutates into machismo. Eighty eggs incubated at 21°C yielded just three males; at 22°C, all hatched out male.
In a warming world, that poses tuatara with a problem.
Already, on the Cook Strait island of North Brother, 60 percent of tuatara are male. Researchers believe that if global warming continues every egg on the island will hatch a male by the mid-2080s.
The consequences are obvious. The Brothers’ population is already showing the signs of stress caused by more competition and violence. Even under ideal conditions, tuatara are slow, infrequent breeders: females lay eggs every four years on average, and on North Brother some lay only every nine years.
Tuatara and their ancestors have survived climate upheaval for 200 million years but now, say scientists, the climate is changing so rapidly that a critical two-degree temperature increase might happen within the lifespan of a single tuatara, which can live for more than a century.
Climate change is outpacing evolution. Everything now depends on the ability of individuals, not generations, to adapt. Conservation managers are investigating whether tuatara could be shifted further south, to Dunedin, ahead of the warming front. In the future, we may only be able to see tuataras in captivity.
What you can do:
- Whatever you do to curb climate change is going to help tuatara and many other native species. Don’t drive more than you need to. Restrict your air travel. Insulate your house. Switch to low-energy options.
- Donate to the Auckland Zoo Conservation Fund, which assists conservation projects for New Zealand native species, including the tuatara. Find out more at www.aucklandzoo.co.nz
- Support mainland sanctuaries, such as the Karori Wildlife Sanctuary, which are breeding tuatara in captivity.
- Find out more at www.victoria.ac.nz/sbs/tuatara
Kiwi
The brown kiwi is in “serious decline”. That’s down to some devastating maths; 95 percent of kiwi chicks are killed by introduced cats, ferrets and stoats
Our brand, our heritage, our character. We are Kiwis; the kiwi is us. But it’s been predicted that, outside specially managed sanctuaries, kiwis could disappear within decades. There were millions of them just two centuries ago; 70,000 remain.
There are at least five species of kiwi, encompassing 11 genetic varieties. The Haast tokoeka and the rowi are listed as nationally critical. The brown kiwi is in “serious decline”. That’s down to some devastating maths: 95 percent of kiwi chicks are killed by introduced cats, ferrets and stoats.
To stem that slaughter, BNZ Operation Nest Egg ‘medevacs’ wild eggs to safe incubation in captivity. Once the hatchlings reach around a kilogram, the critical weight at which they can defend themselves against stoats, they’re released back into the forest. There are also some 80 community conservation programmes, committed to wresting our icon from the jaws of pests, and extinction.
What you can do:
- Support the BNZ Save the Kiwi Trust—it’s put $7 million into kiwi conservation since 1991.
- Donate to a community kiwi conservation programme in your area (www.savethekiwi.org.nz/KiwisSavingKiwi) or, better still, join up.
- Keep your dog on a leash in kiwi habitats.
- Read the Good Cause supplement for more information and ways to help.
- Subscribe to Good and we’ll donate $9 to the BNZ Save the Kiwi Trust.
Grey duck
As a kid, you probably fed grey ducks at your local pond. Now, says Department of Conservation technical support officer Colin Miskelly, they could disappear inside a decade: “They’re going down the gurgler.”
A New Zealand native, the grey duck prefers unmodified forest streams and wetlands—a habitat in short supply these days. Ninety percent of our wetlands have vanished.
The grey duck is almost a lost cause. “Within the next decade, there will be no pure grey ducks in existence”
A similar loss of lowland forest meant the grey duck was already on the back foot 100 years ago, when we introduced the mallard, an adaptable, aggressive, northern hemisphere species, for duck shooting. It warmed to our highly modified agricultural habitat and rapidly colonised the country, hybridising with grey ducks as it went.
“The mallard is a very adaptable bird,” says Ducks Unlimited president Ross Cottle, “and he doesn’t care who he breeds with.”
Before 1958, hybrid frequency was less than three percent. By 1977, mallards accounted for 82 percent of the mallard-grey duck population. A 1982 study revealed that the proportion of pure grey ducks had plummeted to 4.5 percent; a figure, the paper notes ominously, “below the level suggested for the maintenance of a species”.
Colin says the grey duck is almost a lost cause. “Within the next decade, there will be no pure grey ducks in existence.”
What you can do:
- Short of shooting your legal bag of mallards, not much.
- Support Ducks Unlimited all the same. It has no grey duck breeding programme yet, but does great work restoring and protecting wetlands. It also has a breeding programme for the endangered native brown teal. Find out more at www.ducks.org.nz
Whitebait
“During the months of March and April may be seen at high water spring tides countless myriads of small fish from four to six inches in length, making the water literally boil, wherever any rushes or brushwood exist by the river or creek margin.”
So reported DH McKenzie in 1904 from the mouth of the Rangitikei River. But whitebait, a collective term for the juveniles of five native fish species, no longer throng our waterways.
All whitebait species—koaro, inanga, shortjaw kokopu, giant kokopu and banded kokopu—are in decline; two of them are listed as threatened species. The reasons? We like our streams manicured; all those snags and tracts of reeds and rushes they used to spawn in are gone. In their place are concrete culverts and dams blocking the fishes’ path to the sea, preventing them from breeding.
Whitebait will not return to muddy or polluted streams, which rules out many of their former haunts. A Department of Conservation survey this year found that two-thirds of spawning areas have been damaged.
And finally, some industrious members of the angling fraternity—those fishers who pursue non-trout prey such as carp, tench and rudd—persist in illegally stocking local waterways with their favoured noxious fish, which promptly devour our native taonga.
What you can do:
- Everything you can to protect stream quality. Don’t wash out your paint brushes, or clean your car, where polluted water can run into storm water drains; those drains run straight to your nearest creek.
- Report sediment run-off from any earthworks and developments to your regional council.
- If you want to eat whitebait, catch it yourself. If commercial sales decrease, some pressure on whitebait populations may be relieved while we tackle the main cause of decline: water pollution.
Maui’s and Hector’s dolphins
New Zealand is a strident critic of whaling, but two of the world’s rarest marine dolphins are being killed by set and trawl nets in our very own waters.
Maui’s dolphin, or popoto, lives only in New Zealand. There are perhaps 111 left, living in small groups along the northwestern coast of the North Island. Their future looks gloomy. Population models reveal we can’t afford to lose more than one every seven years from human impact.
That’s unlikely. Four Maui’s were found dead between November 2006 and March 2007.
That’s because the little dolphins prefer murky inshore and harbour waters—precisely the places fishers leave set nets to trap flounder and dogfish. The dolphins’ sonar system, it seems, cannot detect monofilament mesh. They quickly become entangled and drown.
DNA studies have shown that around the time monofilament gill nets appeared in the 70s, numbers of Maui’s dolphins plummeted, squeezing them through a genetic bottleneck that has left them in a weakened state, more susceptible to diseases.
Set nets and other fishing devices are known to have killed at least 63 of Maui’s close South Island cousin, the Hector’s dolphin, since 1988; 19 drowned in a single summer. A National Institute of Water and Atmospheric Research risk analysis found that some 100 Hector’s are killed every year, based on fisheries observer records.
“Hector’s have lost over 70 percent of their population in the last 30 years,” says Chris Howe, executive director of WWF, New Zealand. “Just 111 Maui’s dolphins means there might be around 28 breeding females—barely a viable population.”
In 2003, despite legal challenges from fishers, the government declared a set net ban over a small part of Maui’s range. This was extended last May, along with measures to better protect Hector’s dolphins around the South Island.
The Federation of Commercial Fishermen promptly took the decision to court. This September, the High Court placed an injunction on some of the commercial set net bans, which were to have taken effect on October 1 this year.
What you can do:
- If you disapprove of the fishing industry’s attempts to overturn protection for Maui’s and Hector’s dolphins, let them know. Write to Owen Symmans, Chief Executive of the New Zealand Seafood Industry Council, Private Bag 24-901, Wellington 6142; email him at [email protected].
- Vote with your wallet. When you buy fish, ask the retailer how it was caught. Don’t buy fish caught in inshore set nets, such as flounder, butterfish (sometimes sold as greenbone), dogfish and rig.
- Learn more at the WWF-NZ website; click Take Action for Maui’s for more ways to help.
New Zealand sea lion
Our native sea lion is the world’s rarest. A population of 12,000 sounds healthy, until you learn that the North Pacific Steller’s sea lion is endangered, despite numbers of 80,000.
Once found around the country, the New Zealand sea lion now survives only on the subantarctic Campbell and Auckland Islands. Every summer, the Minister of Fisheries has permitted around 90 to drown in the nets of squid trawlers.
The Ministry extrapolates estimated deaths from those recorded on the few squid vessels that carry observers.
Last season, 46 were calculated to have died.
But every female that dies has next year’s pup inside her, and another back on the beach, where it will starve to death. Arguments continue as to whether the New Zealand sea lion can long endure those losses.
What you can do:
- Each year, the Ministry of Fisheries invites submissions when setting its sea lion ‘fishing quota’. Let it know what you think.
- If you disapprove of the death of a theoretically protected species in the name of commerce, don’t buy any domestic squid products.
- Email the DeepWater Group and tell it about your consumer choice.
Long-finned eel
Is there a Kiwi who didn’t grow up around eels? Going eeling was once an Antipodean rite of passage, but the long-finned eel needs clear, clean waterways, and it’s running out of places to live.
Massey University freshwater ecologist Mike Joy says we could lose the creature altogether, thanks to worsening pollution and commercial eeling. “In a single South Island river, a recent survey counted 500 eels; 477 of them were males. That’s because the big ones are females, and the commercial fishers just take them out,” he says.
Every summer, the Minister of Fisheries has permitted around 90 native sea lions to drown in the nets of squid trawlers
The Ministry of Fisheries points to a management plan for the species, but Mike says long-finned eels cannot be ‘managed’ like other fish, because of their extraordinary life cycle.
A long-fin might live for 40 years in the same river system before leaving for the sea, at the beck of some primal call. Then it will swim some 2,500 kilometres to the fathomless deep of the Tonga trench, to find the first and only mate it will ever have.
“No fisheries model can account for a species that doesn’t spawn until the end of its life,” says Mike. “Every one you take out has never reproduced, nor is it going to.”
What you can do:
- Any community stream care project will help long-finned eels; they can be found in the smallest of urban creeks if the water is clean. Join your local group, or adopt a new stream.
- Submit on district plans and resource consent applications, advocating for sediment mitigation, and against any in-stream engineering, such as culverts and weirs.
- In a recent multiday survey of Wellington’s Hutt River, prime long-fin habitat, he found just three. He wants the fishing to stop—now. “Even then, we may be too late. I hope I’m wrong, but you only have to look at all the graphs.”
Orange roughy
Orange roughy is a deepwater fish, highly sought after by commercial fishers. It grows very slowly, living for up to 150 years around underwater mountains in New Zealand waters. It may not breed until it’s 30 years old, making it critically vulnerable to overfishing.
To try to set ‘sustainable yields’, fisheries biologists compare current population sizes (about which we have very little data) to estimates of the species’ original, unfished biomass. The numbers are sobering. Despite recent quota cuts (the latest was overturned by a legal challenge from the fishing industry), most orange roughy populations languish at a fraction of their former size—some, according to Forest and Bird, are as low as three percent.
Orange roughy are caught in bottom trawls, a method known to cause massive damage to undersea environments by smashing coral ‘forests’, and catching large numbers of unwanted creatures in the process.
What you can do:
- Don’t buy orange roughy, or any bottom-trawled fish.
- Support proposed amendments to the Fisheries Act to allow for greater use of the precautionary principle when setting catch limits.
Fairy tern
With just ten breeding pairs, the fairy tern is New Zealand’s rarest bird. A small seabird now confined to just three breeding sites north of Auckland, the tern needs undisturbed sandy beaches to nest on. That’s a scarce habitat around Auckland. We’ve built baches and condos over much of it, and like to run our dogs, quads and SUVs over what remains.
“One of the real problems with fairy tern is that they occur at sites which are very popular with people,” says Colin Miskelly. “While they could be protected at those sites, any attempt to build those populations up would be difficult, because where would all those birds move to? All the other suitable habitats are already developed.
“They’re on the knife edge.”
What you can do:
- Don’t drive your vehicle on beaches where fairy tern live: Mangawhai, Kaipara Harbour and Waipu Cove.
- Don’t let your dog or kids run ahead in nesting territory.
- Submit against any development proposals in those areas.
Geodorcus stag beetle
On a tiny wave-lashed rock stack in the Hauraki Gulf, New Zealand’s—and possibly the world’s—rarest species clings to life. According to Department of Conservation entomologist Greg Sherley, just one or two dozen Geodorcus stag beetles occupy a few hundred square metres on all the planet.
Wiped out by rats on its main island home, the beetle is now critically exposed to fire, storms, or the arrival of rodents. (Greg has learned not to divulge locations. Shortly after the publication of previous papers, he found that avid beetle collectors had wiped out the very populations he was trying to preserve.)
One thing’s for certain: if all these spiny, squirming, cold-blooded creatures disappeared tomorrow, we would follow within months
The beetle’s last hope lies in intensive management. DOC will try captive breeding a close relative of the beetle (it’s too precious to risk experimenting with in the first instance). If that works, DOC will transfer some Geodorcus beetles to a safe enclosure on a larger island.
Who cares about a beetle, really? Well, DOC entomologist Ian Stringer, for one. It turns out that invertebrates, those teeming billions of earthworms, snails, spiders, mites, insects and sundry other spineless, crawling things, are crucial to our own future.
Without them, says Ian, “the place would be nothing but rotting fungi and a few wind-pollinated shrubs. We’d be eating algae out of the sea or something”.
That’s because invertebrates keep our planet working, doing all our dirty work for us, for free. They consume the biblical rain of dead leaves, and the millions of creatures that die every day, extracting the energy still locked in them. On their own death, invertebrates release that energy for trees and animals—and us—to use again.
As a biologist once put it to me, “They keep all the crap below waist level”.
It’s like a rubbish collection, urges Ian. “We put our rubbish out, and during the night a whole army of rubbish collectors sets to work, but we don’t know about it; in the morning it’s gone.”
One thing’s for certain: if all these spiny, squirming, cold-blooded creatures disappeared tomorrow, we would follow within months.
And that’s why we mustn’t let the Geodorcus stag beetle—or any plant or creature—go extinct. Each and every one is a vital component of a planetary engine room. If it vanishes, that engine starts to misfire. And there are no spare parts.
