By Annie Hill
The original article in Russell Lights | Ngā Mārama o Kororāreka, June 2026 edition
The word ‘predator’ conjures up an image of a wolf or tiger, or maybe a stoat or ship rat but it seems an extreme description for a goat, particularly “invasive predator”. However, semantics apart, as far as our native vegetation is concerned, goats are voracious predators, against which few plants have any form of defence. Feral goats are pests in many countries, and cause long-term problems, largely caused by overgrazing, which can lead to soil erosion, due to the loss of plant roots. In this country, they also destroy habitat, food sources and nesting opportunities for birds and other native animals, as well as spreading invasive plants and weeds in their dung. Due to their adverse effects on biodiversity, they’re included in the 100 World’s Worst Invasive Alien Species. Indeed, even domesticated goats are strongly implicated in desertification in both Africa and Asia, due to their indiscriminate browsing and large numbers.
The first goats to reach Aotearoa New Zealand, were deliberately introduced by Capt James Cook in 1773, to provide food for the ‘natives’. (And so the sorry history of Europeans introducing animals, with the best of intentions and the worst of outcomes, began.) They were also brought here by sealers and whalers for food and bartering. Not content with allowing them to infest the large motu, in the nineteenth century, people took them to smaller islands to serve as a food source for castaways, and they promptly set about destroying the habitat. Over time, farmers imported goats for livestock, fibre and ironically, helping in eradicating invasive plant species. If an enterprise was unsuccessful, the goats were often deliberately released. About 14% of Aotearoa New Zealand is now populated by feral goats, all of which do untold damage to plant life.
While feral goats in Wales, for instance, may look very different from those seen here, they’re all Capra hircus, descended from wild Capra aegagrus. Their appearance depends on the original stock (as with most domestic animals, humans have selectively bred them for desirable traits), with our feral goats being black, white, tan or a combination thereof. Males and females both have horns and both can have beards. The males – billies – are noticeably more massive and shaggier than the females – nannies – and have larger horns. Male feral goats are around 70 cm high at the shoulder and 1.5 m in length, weighing 50–60 kg. They have eyes with oblong pupils, set on the side of the head, which enables them to have almost 360° vision. Goats are often heard before they’re seen, their ‘meh’ bleat sounding quite different from the ‘baa’ of a sheep.
Feral goats are found in a wide range of habitats, from sea level to the alpine zone, in introduced and native grasslands, scrub and forest. Because they’re browsers (eat leaves and shrubs rather than grass), their preferred habitat is forest or scrub-covered upland containing areas of grassland. They’re agility on steep crags and narrow ledges allows them to get to areas deer cannot reach and their depredations can lead to increased soil erosion. They like sunny slopes, making use of open places close to the shelter of forest or scrub, with the highest populations on reverting farmland, in steep hill country. However, they’re also found in exotic and indigenous forests, scrub and shrub lands. Recognised as a threat to native vegetation from the 1890s, they were only identified as a major pest in the 1930s. About half of them are on public conservation land, including the Russell Forest. Goats are hardy and adaptable, coping with most climatic conditions and their population is estimated to be several hundred thousand.
Highly social creatures, goats live in complex societies with distinct herd dynamics and mating habits. They form close-knit groups led by dominant females and within these groups, a strict hierarchy exists, where more experienced and larger individuals assert authority over younger or smaller members. Subordinate animals often engage in “submission displays” by lowering their heads and ears, to signal deference.
The breeding process is led by dominant billies: lower-ranking males may be driven from the herds and excluded from reproduction for several years. Goats are polygynous (one male mates with multiple females) and have high reproductive success. Females can become pregnant from 6 months old, while males become sexually mature at 3½–4 years. Nannies can conceive year round, although mating activity tends to peak December/January and June/July. Gestation takes around 160 days and they give birth to between one and three kids, which are on their feet and active within minutes of being born. (They’re also extraordinarily appealing, which is why so many people are prepared to tolerate goats, in spite of the havoc they wreak on flora); the kids stay with their mother for about 6 months and they can live up to 22 years.
Goats are ruminants with a four-chambered stomach, which allows them to eat many plants which would poison other animals. Capeweed, for example, is generally toxic because of its high nitrate levels, but goats can process these chemicals and eat the plant with little issue. They do find moulds highly toxic and will generally avoid them along with nightshades and wilted fruit trees. Otherwise, goats will generally attempt to eat almost anything that attracts their curiosity, such as tin cans and cardboard. People who claim to have the digestion of a goat are making a good comparison!
Eating the foliage of most trees and plants, goats quickly destroy all understorey vegetation within their reach, up to 2m above the ground, creating openings for invasive weeds. Although many people find this incredible, goats can also climb some trees. They have strong preferences for broadleaf/pāpāuma and māhoe, and will eat these out, before moving on to less desirable plants. They strip bark from trees and their consumption of seedlings, saplings and litter-fall on the forest floor effectively prevents forest regeneration, taking vital food and shelter from native animals, and worsening the effects of the climate catastrophe. Goats also damage young trees in exotic forests, and shrubs and trees in soil-conservation, riparian and restoration planting. Their destruction of undergrowth through browsing and trampling, coupled with the effects of possums in the canopy, often results in permanent damage to native vegetation; regeneration may be halted and palatable species completely lost from such areas. They also compete with native herbivores (such as ducks, rail, parrots and kereru), putting further pressure on already fragile environments.
Goats are sizeable animals and none of the introduced predators offers them the slightest threat. Only feral dog packs could possibly prey on them. Although people actively hunt them both for food and ‘sport’, they have little effect on their numbers; many people are fond of them and, not apprehending the devastation that they cause to native fauna, refuse to allow them to be controlled on their property.
Nanenane | Feral Goat | Capra hircus