Answers to beat ‘extinction crisis’
There is hope for stopping the ‘‘extinction crisis’’ in New Zealand, but a researcher says saving species when numbers get particularly low is ‘‘very complex’’.
The study by researchers from New Zealand universities and other organisations looked at seven species where interventions have been successful – tuatara, saddlebacks or tı¯eke, long-tailed bat, humpback whale, common river galaxiid, Mercury Islands tusked we¯ta¯, and Armstrong’s whipcord hebe.
‘‘The things we think are successful largely come round to paying a lot of attention to these species,’’ lead author Dr Nicola Nelson, an associate professor at Victoria University’s School of Biological Sciences, said.
That sort of attention could not be ramped up across all species. For example, the effort made to achieve success for tuatara could not feasibly be repeated over New Zealand’s 100 or so other species of reptiles.
The paper, published yesterday in the Journal of the Royal Society of New Zealand, ends saying: ‘‘There is no reason why the current extinction crisis facing New Zealand and the world cannot be stopped and reversed by extending the lessons learned from the winners more widely.’’
But Nelson said the issues became ‘‘really complex’’ in species where numbers were particularly low. Two such species in New Zealand were Ma¯ui’s dolphin and ka¯ ka¯ po¯ .
A recent estimate of Ma¯ui’s dolphins put the number of individuals aged over one-yearold at 57-75. A dolphin found dead north of Raglan on Sunday is thought to be a Ma¯ ui’s dolphin. The Department of Conservation puts the number of ka¯ ka¯ po¯ at 149.
Those species were special cases and perhaps at the point where recovery would be very hard because numbers were so low, Nelson said.
Ka¯ka¯po¯ were a success story in that the population was increasing, but it was risky any time numbers dropped close to 100. ‘‘It could be you do everything you can, but you have a couple of deaths and proportionately they make a massive difference,’’ she said.
‘‘When you’re at the caring for individuals stage, you’re very vulnerable no matter what resources you put in,’’ Nelson said.
But she was an optimist. ‘‘I would hate to see those kind of things go on my watch. I wouldn’t like to see us give up.’’