Goat control on Arapawa Island Scenic Reserve

DOC carries out goat control on scenic reserve on Arapawa Island (Arapaoa Island, in the Marlborough Sounds, to protect the reserve’s important remnant Cook Strait forest communities and plant species which today only survive in a few areas.

The island is free of possums but goats and pigs have a significant impact on this vegetation if left unchecked.

A distinctive Cook Strait vegetation

Arapawa Island Reserve. Fenced left
side, unfenced right side.

The native vegetation in the Arapawa Island Scenic Reserve is representative remnants of forest that was once more widespread in the Cook Strait area. It is shaped by the distinctive climate of the Cook Strait narrows – wind, humidity and salt spray – combined with rugged and spectacular topography.

The composition of the native bush is an unusual mix of subtropical kohekohe, warm temperate tawa and montane beech-podocarp-broadleaved forests, in distinct altitudinal zones. It is rare in New Zealand to have possum-free kohekohe forest on such a scale.

Goat control programme

DOC's goat control programme on Arapawa Island is focussed on the scenic reserve and some adjoining private land with the agreement of the landowner. Control of goats on the scenic reserve to protect its distinctive native vegetation has been ongoing since 1978. The area in which goat control takes place comprises about one-third of the goats’ range on the island which is mostly on private land.

In part of the reserve that is fenced and protected from goats and pigs there is impressive re-growth of understory shrubs and trees transforming it into more natural, healthy forest. Seedlings are now abundant whereas before the forest floor was almost bare of new growth due to grazing by goats and pig rooting.

There is little fencing between private land and most of the reserve, goats and pigs regularly spill over into the reserve from the private land. Consequently in these parts of the reserve goat and pig damage to the native vegetation is still occurring and control is needed to reduce their numbers to low levels.

Why goats are controlled

DOC's goat control programme on Arapawa Island is focussed on the scenic reserve and some adjoining private land with the agreement of the landowner. It is needed to protect the reserve’s important remnant Cook Strait forest communities and plant species which today only survive in a few places. Goats, and also pigs, have a significant impact on this native vegetation if left unchecked.

The native vegetation in the Arapawa Island Scenic Reserve is representative remnants of forest that was once more widespread in the Cook Strait area. It is shaped by the distinctive climate of the Cook Strait narrows - wind, humidity and salt spray - combined with rugged and spectacular topography. The composition of the native bush is an unusual mix of subtropical kohekohe,warm temperate tawa and montane beech-podocarp-broadleaved forests, in distinct altitudinal zones. It is rare in New Zealand to have possum-free kohekohe forest on such a scale.

In part of the reserve that is fenced and protected from goats and pigs there is impressive regrowth of understory shrubs and trees transforming it into more natural, healthy forest. Seedlings are now abundant whereas before the forest floor was almost bare of new growth due
to grazing by goats and pig rooting.

There is little fencing between private land and most of the reserve, goats and pigs regularly spill over into the reserve from the private land. Consequently in these parts of the reserve goat and pig damage to the native vegetation is still occurring and control is needed to reduce their numbers to low levels.

Goats are reduced not exterminated

DOC's goat control programme on Arapawa Island is focussed only on the scenic reserve, to protect its important and distinctive Cook Strait vegetation, and periodically an adjoining area of private land with the agreement of the landowner. The goat control aims to reduce goat numbers to low levels in the reserve.

The area of ongoing goat control, 1100 hectares, comprises around just one third of the goats’ range on the island which covers approximately 3350 hectares.

DOC does not consider its goat control programme would lead to the extinction of the Arapawa goats on the island.

Number of goats

The number of goats on Arapawa Island and on the Arapawa Island Scenic Reserve is not exactly known. We have been advised that it wouldn’t be easy to get an accurate or even reliable count because of the island’s difficult terrain and now extensive vegetation cover. Also, goats move around and wouldn’t be visible from the air during the day as they are usually resting then under trees or bushes. A ground survey wouldn’t be practical and it would need to be done from the air.

We understand it is estimated 307 of these goats are held by registered breeders off the island, including at sites in New Zealand, the United States and Great Britain.

A viable breeding population 

The number of goats on the island isn’t known but the fact ongoing goat control has been required on the reserve since 1978 suggests a viable breeding population of the goats remains on the island.

DOC's goat control programme on Arapawa Island is focussed on the scenic reserve and protecting its important and distinctive Cook Strait vegetation. Periodically it includes an adjoining area of private land with the agreement of the landowner.

DOC does not consider its goat control programme would lead to the extinction of goats on Arapawa Island. Our goat control is not aimed at eradicating the goats on the island, just reducing their numbers to low levels on the reserve.

The area of ongoing goat control only represents approximately a third of the goats’ home range and goats are still regularly moving into the reserve from private land.

There are numerous goat breeders here and overseas breeding Arapawa goats.

Goat protection

Goat advocates say the goats are a unique and rare species and may ask why DOC isn't involved in protecting them in accordance with the Rio Convention 1992 which New Zealand is a signatory to.

But the reserve is not an appropriate place for the goats given the destructive impact the goats have on the reserve’s native vegetation. Protection of the goats is best achieved by people who value them holding and managing them on fenced private land.

The New Zealand Biodiversity Strategy identified the need to ensure that protection was made available for those species introduced to New Zealand but regarded as important because of their international status, the importance of their genes or their role in New Zealand’s development. The Biodiversity Strategy specifies that this should be done provided it does not pose a threat to indigenous species.

It is not a role of DOC to provide for the protection of introduced species; our responsibility is the preservation of New Zealand’s native plants and animals for the people of New Zealand. This includes a responsibility to preserve the important remnant Cook Strait forest and plants and other native species on Arapawa Island scenic reserve, including the unique Marlborough green gecko, also found in its yellow form on the island, and giant Powelliphanta snails, all of which are part of our country’s unique natural heritage.

We are aware it is believed that the goats on Arapawa Island are descended from goats liberated by Captain Cook on Arapawa Island in 1773 but it is not clear whether the goats on the island today are remnants of the Cook goats. The NZ Rare Breeds Conservation Society’s website states, “Cook actually recorded that the goats he released in East Bay on Arapawa Island – and which he had taken aboard at the Cape Verde islands on the voyage out – were killed before he left the country”.

The earliest known record of goats being seen on Arapawa Island since Cook’s time was in 1839. Whalers established on Arapawa Island in 1827 at Te Awaiti and it is highly likely they brought goats with them for food.

It has not been definitively established that the Arapawa goat is a unique and rare species. The 2007 genetic analysis that was undertaken in Spain concluded the Arapawa goat is “a unique genetic resource when compared to other goat breeds”. It was not tested against the Old English Goat as none exist to enable this and it was also not tested against other New Zealand mainland goat populations. There is a view held that even if the earlier Cook’s goats survived they would now likely be of mixed ancestry as islanders say over the years mainland goats have been released onto the island and interbred with the island goats.

Fencing more of the reserve to keep out goats and pigs

It would be extremely expensive and difficult to erect and maintain a fence over other parts of the boundary between the reserve and private land which stretches for several kilometres along a rocky ridge. There would be difficulties in getting fence posts into the rock surface and the salt laden air would mean high maintenance costs. A number of landowners have indicated they could not afford to install a boundary fence or share the cost of that with DOC.

DOC reached an agreement with the majority of a group of neighbours to the reserve with a close interest in the goat control on the use of a range of techniques for its goat and pig control. These were seen as a more practical option than fencing which would be extremely costly and difficult to erect. The measures include ground hunting, using indicator dogs to locate goats and pigs, and helicopter control at times on reserve land.

Fencing on private land

DOC has no objection to goat supporters creating a fenced area on private land for goats on Arapawa Island. We see this as a good way in which to achieve their aim of protecting the goats on the island. It is not in line with DOC’s role and responsibilities to provide this fenced area as our role is focussed on preserving New Zealand’s native species and managing areas of public conservation land.