Media Release
Saturday, 13 September 2025
Feral Deer: An Environmental Crisis, Not a Cute Debate
In a recent Facebook post, Cr Tim McMahon asked whether the many wild deer in Toowoomba are a pest or a charming sight, noting that “they are a declared pest… but many people love the look of them running wild.” Framing of feral deer as a debatably “opinion” piece based off of aesthetics is imprudent- feral deer are a serious, significant ecological threat. Cr McMahon is the TRC Portfolio Leader for Environment, so his casual attitude toward this pest is troubling.
Australia’s ecosystems evolved without hoofed mammals, and global science shows that introduced hoofed herbivores inflict massive damage. For example, a recent NSW government report warns that invasive pests threaten more than 70% of the state’s threatened species and ecological communities. Feral deer fit squarely into this category: they are an emerging pest whose numbers are exploding (current estimates are 1–2 million nationwide and rising). The federal Agriculture Department confirms that feral deer already cost Australian communities about $91 million per year and cause significant environmental damage and ecological degradation. In practical terms, they destroy native plants, erode soil, foul waterways, and spread disease. In other words, they devour the very fabric of our bushland and continue to push our threatened species closer to extinction.
Australia isn’t home to any native hard-hoofed animals. Our flora and fauna lack evolved defences against hooves, so species like deer (and horses, cattle, goats, pigs, etc.) cause remarkable damage. Feral horses, for example, have been documented to produce immense ecological damage in alpine areas by overgrazing and trampling. Deer behave similarly: as large herbivores they can strip entire areas of vegetation and then trample the exposed soil. Research shows that their constant feeding causes soil erosion through the removal of vegetation, and their trails across streams widen and silt up waterways.
The impacts of feral deer are well-documented:
Native Vegetation Loss: Studies show deer reduce biodiversity by reducing the number, cover, abundance and diversity of native plants, including saplings and understorey that other species rely on. In Victoria, it’s estimated that deer are already harming over 1,000 native plant and animal species and at least a dozen ecological communities (including threatened ones). Deer browse relentlessly on seedlings and shrubs, altering forest structure. Local landcare groups report deer frequently destroying newly planted revegetation. Heavy browsing on young trees has also been recorded causing… death of saplings. This undermines restoration efforts and chokes out native plant regeneration.
Soil Erosion and Landscape Damage: Hoofed deer compact and churn soil. As trees and grasses disappear under overgrazing, the earth erodes more easily. Deer wallow in mud, forming ponds that then expand into gullies and bare dirt. Scientists note that deer trampling causes soil disturbance, erosion, and impact(s) on water quality. In mountain regions, feral horses (analogous to deer) are shown to create deep erosion scars and widen creek beds. We cannot let our regional trails and riparian zones suffer the same fate.
Waterway Pollution and Habitat Degradation: Deer contaminate streams with faeces and trampling, harming aquatic life. They rip up streambanks when wallowing or crossing, making waterways shallow and silty. Queensland authorities specifically warn of waterhole fouling and creek erosion by deer. These impacts degrade frog, fish and invertebrate habitat, and diminish water quality for all wildlife.
Spread of Weeds: Deer carry seeds of invasive plants in their fur and dung as they roam, introducing weeds into pristine areas. The upper Darling Downs is already being invaded by weed species partly because feral animals move seeds around. Scientific reviews note that weed proliferation simplifies the composition and structure of vegetation; meaning native wildflowers and grasses are replaced by a few hardy exotics.
Biodiversity and Ecosystem Collapse: When deer thin out native understorey and destroy groundcover, small wildlife lose shelter and food. Ground-nesting birds, reptiles and small mammals are especially vulnerable. Entire plant communities can collapse: Victorian conservation authorities even list Sambar deer under the Flora and Fauna Guarantee Act as a “potentially threatening process” because they “reduce the biodiversity of native vegetation”. In Alpine National Park, deer have already been observed destroying rare peatbog habitats critical for unique plants and the vulnerable Stocky Galaxias fish. In fact, environmental studies from around Australia (and New Zealand) show that high deer densities can severely reduce ecosystem resilience.
The science is unmistakable: feral deer simplify and degrade our landscapes. They are neither charming nor benign. By the same token, this is not an issue best decided by a public popularity contest or photo op. It’s an environmental emergency. A recent national plan, the Australian National Feral Deer Action Plan 2023–2028, explicitly aims to “stop the spread, suppress, or eradicate feral deer populations to reduce their impact on environmental, cultural and social assets” If the federal and state governments are treating deer removal as a high priority, local leaders should too.
We urge Council and the community to stop treating wild deer as a whimsical ‘debate’ and start treating them as the pests they are. No genuine conservationist says “I like them, so it’s okay for them to rampage through reserves.” To those who express aesthetic affection for deer: compare a grassy slope thronged by deer to that same slope bare and trampled, strewn with rubbish, scarred by erosion and strewn with weeds. The choice is obvious.
Anyone who truly cares about Toowoomba’s bush will insist on evidence-based action, not wishful thinking. The deer are declared pests for reason. Let’s act according before any more woodland is lost or endangered species slip silently toward extinction.
Sources:
Department of Agriculture and Water Resources. (n.d.). Feral deer fact sheet. Australian Government. https://www.agriculture.gov.au/sites/default/files/documents/fs-feral-deer.pdf
Department of Climate Change, Energy, the Environment and Water. (2023, August 15). National Feral Deer Action Plan released. Australian Government. https://www.dcceew.gov.au/about/news/feral-deer-action-plan
Department of the Environment, Tourism, Science and Innovation (DETSI), Queensland. (2024, September 20). Feral deer eradication protects threatened flatback turtles. Queensland Government. https://www.detsi.qld.gov.au/our-department/news-media/mediareleases/2024/feral-deer-eradication-protects-flatback-turtles
Frontier Economics. (2023). An analysis of the economic, social and environmental cost of feral deer in Victoria. Invasive Species Council. https://invasives.org.au/publications/an-analysis-of-the-economic-social-environmental-cost-of-feral-deer-in-victoria/
Invasive Species Council. (n.d.). Feral deer. https://invasives.org.au/our-work/feral-animals/feral-deer/
Invasive Species Council. (n.d.). Strategy for invasive species in Australia. https://invasives.org.au/our-work/feral-animals/strategy-invasive-species-australia/
Kaltenborn, G., & Palmer, M. A. (2017). Interactive effects of deer and invasive plants on native plant cover. The Scientific World Journal, 2017, Article 5710600. https://pmc.ncbi.nlm.nih.gov/articles/PMC5710600/
Local Land Services NSW. (2024, November 6). Feral deer in NSW a threat to health and agriculture. https://www.lls.nsw.gov.au/news-and-events/news/statewide/2024/feral-deer-in-nsw-a-threat-to-health-and-agriculture
McDowell, R. W., & Catto, P. M. (2007). Water quality in headwater catchments with deer wallows. Journal of Environmental Quality, 36(5), 1378-1384. https://www.researchgate.net/publication/6202770_Water_Quality_in_Headwater_Catchments_with_Deer_Wallows
McLeod, R., Bomford, M., & Henzell, R. (2023). Ecology, impacts, and management of wild deer in Australia. Wildlife Research, 50(9), 677-688. https://www.publish.csiro.au/wr/pdf/WR23092
Murraylands and Riverland Landscape Board. (n.d.). Feral deer in NSW. https://mli.org.au/feral-deer-in-nsw/
National Feral Deer Action Plan Working Group. (2023). Australian National Feral Deer Action Plan 2023–2028. Australian Government. https://feraldeerplan.org.au/wp-content/uploads/2023/08/National-Feral-Deer-Action-Plan-2023-28.pdf
Pople, A. R., et al. (2024). Ecological separation of wild herbivores in northern Australia and a discussion of the ecological niches of introduced ungulates. Animals, 14(9), Article 1450. https://pmc.ncbi.nlm.nih.gov/articles/PMC11171043/
Queensland Government. (n.d.). Feral fallow deer. https://www.publications.qld.gov.au/dataset/e1aa5912-b5c2-4faa-a583-3c04cdba950d/resource/eac66365-7c63-4f39-8960-7392eddf1915/download/feral-fallow-deer.pdf
Reclaim Kosci. (n.d.). Gallery of damage. https://reclaimkosci.org.au/myths-v-facts/gallery-of-damage/
South Burnett Regional Council. (n.d.). Rusa deer fact sheet. https://www.southburnett.qld.gov.au/files/assets/public/v/1/living-here/documents/ipa_rusa_deer_factsheet.pdf
Burns, H., Gibbons, P., & Claridge, A. (2021). Quantifying variations in browsing pressure caused by feral deer for a range of threatened ecological communities and plant growth forms. Austral Ecology, 46(7), 1134-1147. https://doi.org/10.1111/aec.13050
Recent Comments