The blindspot hampering efforts to save our national icon

Scientists still don't know enough about the genetics of New Zealand's national icon to help protect it in the long term, a new review has found. Photo / Dean Wright

Scientists still don't know enough about the genetics of New Zealand's national icon to help protect it in the long term, a new review has found.

In a just-published study, Massey University researcher Malin Undin and colleagues canvassed more than 30 years of research into kiwi genetics.

While this work has shown how kiwi differed genetically between areas, there was little understanding of how much they've adapted to different environments - or how much the birds were inbreeding.

As at the most recent estimate, there were fewer than 70,000 - a fraction of the 12 million that once roamed freely in our prehistoric wilderness.

Through efforts like Operation Nest Egg and the Kiwi Recovery plan, the Department of Conservation (DoC) and groups like Kiwis for Kiwi battling to reverse an annual loss 2 per cent loss rate.

Massey wildlife biologist Associate Professor Isabel Castro, a co-author of the new study, saw kiwi conservation as reliant upon two basic things.

One was knowing enough about a managed species to properly direct conservation efforts, and the other was maintaining a healthy genetic and behavioural diversity within them.

DoC's recovery plan, which aimed to grow the kiwi population to 100,000 this decade, stated scientists now had the genetic knowledge and management tools to ensure kiwi were being given the "highest chance" of long-term success.

Yet it flagged several issues.

The results of genetic research weren't always publicly available or incorporated into management, and there was confusion about how to manage "hybrid" birds, or those suspected to have problematic genes.

It also pointed out a need to boost research on non-invasive genetic techniques and genomic approaches for kiwi conservation, and to learn what the right groups were to retain remaining genetic diversity.

"The kiwi conservation community recognises [the] situation and that there is a need to incorporate genetic management as a complement to predator management," Undin said.

"Usually, genetic management involves moving birds between areas. However, genetic management is complicated and knowing which birds to move where and when requires a lot of scientific data.

"This data has not been available to the kiwi conservation community, but there has been debate as to whether this lack of data is due to a lack of appropriate studies or a lack of access and compilation of already existing results."

In the review, assessing 40 studies to date, Undin and colleagues concluded our current understanding wasn't enough to guide genetic management, manage diversity, or even lock in the species' future sustainability.

"The main knowledge gap is that, while we know that kiwi from different parts of the country differ genetically, but we still do not know why," Undin said.

"Most importantly, we do not to what extent the differences are the result of local adaptation.

"A consequence of this is that we risk conserving unmeaningful or artificial differences, which ultimately could mean that we lose rather than preserve diversity.

For instance, she said, kiwi were currently divided into five species, and then further into 14 management units.

"The current guidelines suggest that each of these units should be managed separately and that mixing them should be strictly avoided," she said.

"However, my results suggest that with our current genetic knowledge we actually don't know if the current splitting makes sense from a genetic diversity perspective, and whether keeping the units separate has more negative than positive consequences for the future success of kiwi."

Castro added: "We appreciate and acknowledge that the studies conducted to date provide a foundation to advance understanding of this iconic genus in New Zealand.

"However, our main conclusion is that current knowledge of kiwi genetics is still insufficient to inform conservation decisions and develop robust management plans for long term sustainable and diverse kiwi populations."

Castro said a "serious deficiency" was that scientists still didn't understand the nature and extent of the genetic differences observed among taxa and populations.

Currently, kiwi were being managed through a combination of pest control in the wild and translocating adults, juveniles or eggs to predator-free refuges.

When it came to planning successful translocations, Castro said detailed information about genetic and epigenetic variations was key.

"Decision-making in the absence of this information risks leading to management strategies that are insufficient - or even harmful - for future population sustainability," Castro said.

"This is a situation facing conservationists worldwide.

"The dilemma is that there is a desire to improve population numbers of threatened species rapidly, while maintaining, increasing or restoring genetic diversity - but sufficient genetic data to support successful management are not available."

Among its objectives for this decade, DoC stated a need to maintain the existing genetic diversity of all kiwi, and to ensure managers understood the importance and practical application of genetic principles.