Feral goats (Capra hircus) are a major threat to our rangeland vegetation throughout Australia, where they roam the countryside largely unmanaged.
They compete with native fauna species, browse and overgraze native vegetation and also have a negative impact on the soil stability, causing often irreversible erosion damage.
The impact of feral goats is most obvious during periods of drought where already stressed landscapes and native species are clinging on to life until the next rainfall event.
For those of you not familiar with the browsing impacts on vegetation by feral goats, or hemlines, Kurt Tschirner’s blog from 2018 is a great starting point.
In addition to these direct impacts on native vegetation, they also reduce vegetation cover, increasing the impact of erosion, prevent recruitment and regeneration of fragile ecosystems, spread weeds, foul waterholes, potentially spread disease to other domestic stock (e.g. foot-and-mouth disease, foot rot, Johne’s disease), outcompete native herbivores such as the Yellow-footed Rock Wallaby and remove the necessary cover for survival of other small native vertebrate species, leaving them more susceptible to predation.
So where did the problem begin? Goats arrived in Australia with the First Fleet in 1788, when they were brought across on board for milk and meat production. They were slowly released on to remote islands, and to areas on the mainland as a remote food source and more recently were used to remove weeds from plantation areas and through the pastoral regions further into interior Australia.
Like many other feral herbivores (e.g. deer), feral populations have spread from poorly managed domestic stock.
It's now estimated there are more than two million feral goats throughout Australia, mainly through rocky or hilly country in the semi-arid areas of NSW, SA, WA and QLD.
Their success through these areas is attributed to a broad and varied diet (often people joke that they can live on dirt!), high reproductive output (females breed in their first year, can breed twice a year and twins and triplets are not uncommon), and generally a lack of natural suppression from predators (i.e. they're most abundant where the control of an apex predator is a priority).
Under most relevant legislation it's the responsibility of land managers to control feral goats, and where they're farmed, ensure that they're contained with adequate fencing. In South Australia, legislation outlined in the Natural Resources Management (General) Regulations 2005, are very clear about the responsibilities of landholders in controlling feral goats.
Each year on Boolcoomatta we work hard to control goat numbers. In addition, neighbouring Bimbowrie Conservation Park conducts aerial goat control that encompasses the rocky hills, as part of Operation Bounceback, to deliver positive conservation outcomes for Yellow-footed Rock Wallabies and the native vegetation in this area.
Frustratingly there's ongoing pressure from feral goats, despite some promising results over the years we've worked in the region. On the back of long and continued drought conditions, feral goat mustering is becoming an alluring alternative to sheep grazing.
Driving to Boolcoomatta, the extent of the problem is glaringly obvious, with feral goats lining the Barrier Highway right to the NSW border, the odd road train their only concern.
The feral goat challenge is further highlighted by tagged goats turning up that have wandered into SA, having escaped from goat farms in NSW, despite requirements to contain farmed goats.
The problem of feral goats, including tightening compliance legislation around the management of feral goats for profit, needs to be urgently addressed to protect landscapes in the South Australian rangelands.