The Australian Capital Territory's cherished national parks are under siege from a rising tide of invasive species, with experts warning feral deer, horses, and pigs are becoming increasingly common and pose a severe threat to delicate ecosystems.
Zero Tolerance for Hoofed Invaders
While the ACT maintains a strict zero-tolerance policy for feral horses, or brumbies, the same level of control has proven elusive for other pests. Since 2011, authorities have culled nine feral horses in Namadgi National Park, with seven of those removals occurring in 2024 alone through thermal aerial and ground shooting programs.
Michaela Watts, executive branch manager for the ACT Environment, Water and Emissions Reduction directorate, emphasised the significant damage hard-hoofed animals cause. "They don't belong there, and they do have a really significant impact on some of these really delicate ecosystems, like the bogs and fens," she stated. Rangers constantly monitor for signs of incursion, particularly from the thousands-strong population in the neighbouring Kosciuszko National Park in New South Wales.
Jack Gough, CEO of the Invasive Species Council, applauded the ACT's proactive stance. "The numbers of feral horses are still out of control," he said, noting that the ACT's early intervention has prevented the crisis seen in Kosciuszko, where numbers once ballooned to an estimated 25,000.
Deer Populations Surge Despite Culling Efforts
In contrast to the successful horse management, feral deer numbers across south-eastern Australia are surging. The ACT's own control programs highlight the scale of the problem: 527 deer were culled in 2025, a sharp increase from 357 in 2024 and 356 in 2023.
Despite these intensive efforts, Ms Watts confirmed that Parks ACT has not yet recorded a decrease in the overall deer population. "We can't stop, we've just got to keep on working on it and work to eradication," she said, noting the animals' disregard for jurisdictional boundaries. The pests are increasingly moving into peri-urban areas, raising concerns about public safety and animal-vehicle collisions.
Pigs in the Suburbs and a Call for Public Vigilance
The feral animal issue is now knocking on Canberra's suburban door. Recent sightings of a feral pig in the western suburb of Coombs amused residents but underscored the expanding range of these invasive species. The 2025 aerial control program also removed 247 feral pigs and 69 feral goats from areas including the Murrumbidgee River Corridor and Tidbinbilla Nature Reserve.
Authorities are urging Canberrans to be vigilant. Ms Watts encouraged residents to report sightings of large numbers of feral animals to Access Canberra. Early intervention is key to preventing pests from becoming established in urban areas, where they can cause significant damage and safety hazards.
The situation presents a clear challenge: while the ACT's firm policy has kept feral horse numbers in check, the battle against other invasive species like deer is intensifying, demanding continued and expanded management efforts to protect the region's unique natural heritage.
