About Deer
Identification and monitoring of deer and their impacts
Deer are a species that were introduced to Australia back in the 1800s for hunting. Further deer have been released into the environment since then, assisted by escapes and releases from deer farms. Deer species are estimated to occupy around 40% of Victoria.
The Yarra Valley (Steels, Dixon, Chum Creek) has 2 main deer species - Sambar and Fallow with Red Deer as a developing threat currently located in Christmas hills - all of which look a little different, but leave similar signs of their presence, and have similar damaging impacts.
Whilst deer are currently protected under the Wildlife Act as a Game species (only in Victoria and Tasmania with all other states now recognising them as a pest species), they are 'unprotected on private land where they are causing damage to plants and property.
Deer identification and monitoring information
Below are some resources and videos on identification and monitoring; and how to record deer sightings, damage and control using DeerScan.
Factsheet - Deer Management Factsheet(PDF, 1MB)
Factsheet - Deer Identification - Species, Scats, Signs and Damage(PDF, 3MB)
Factsheet - Monitoring deer populations, assessing damage and how to use DeerScan to record your findings(PDF, 2MB)
Videos:
Webinar recording - Nillumbik Deer Information Session (Introduction to the deer species in Nillumbik, where they are found, their impacts, the legislative framework around deer, responsibilities for management, control options, and community approaches to managing deer together
Webinar recording - Identifying and monitoring deer
Webinar recording - Deer sounds, scats and hair
We encourage everyone to use the FeralScan (Deer Scan) app to record your findings. This information is really valuable in helping to understand the scale and range of the issue, and where to prioritise deer control effort and investment.
Source of information above (95%): https://www.nillumbik.vic.gov.au
📈 Key Growth Insights
Reproductive Rate: Sambar typically calve between April and August, starting at around 1.8 years old and continuing until about 12.75 years 2.
Population Expansion: Despite heavy culling and hunting efforts (e.g. 90,000 harvested in 2016), the population continues to grow and expand its range, especially in Victoria, NSW, and South Australia 3.
Habitat Occupation: Sambar now occupy over 70,000 km² of Victoria alone, with increasing density in forested, rural areas and peri-urban zones.
Intrinsic Growth Rate: Scientific modelling using demographic data suggests an annual growth of 15–24% depending on local conditions.
🐮 Samba Deer Impact - Comparison to Livestock
For context, here's how Sambar grazing compares:
👉 Fun Fact: 226 deer ≈ the pressure of 1,000+ sheep, especially in sensitive regrowth zones.
Samba population growth is 15% to 24% per year. If no culling was done for 10 years, the 226 deer would reproduce to 3,564 deer (at 15% growth), equivalent to 15 million kg per year. That’s the same as 88,650 five-foot round bales of hay @ 30 bales per semitrailer or 1,182 semi-trailer truck loads of hay per year.
Remember, recreational hunters are not keeping the population growth down, which means the government must support culling programs to control numbers to reduce environmental, agricultural, rural, peri-urban impacts and road traffic accidents
📉 Minimum Annual Cull Rates to Halt Population Growth
To effectively reduce deer populations—especially species like Sambar—you need to cull at least 40% of the population annually under favourable conditions.
Samba deer populations can grow 15–24% per year, depending on species and habitat.
If culling falls below the threshold, populations continue to grow, often rebounding faster due to reduced competition (a phenomenon called compensatory rebound).
Time-lapse of deer growth since 1996
In Australia, feral deer populations have exploded since the 1970s—from an estimated 50,000 animals in 1980 to 1–2 million by 2022, and still rising. 1
1970s–1980s: Deer populations were relatively contained, mostly on private estates or acclimatisation societies.
1990s–2000s: Escapes and deliberate releases led to wild herds expanding across bushland and farmland.
2010s–2020s: Range nearly doubled; deer now occupy over 70,000 km² in Victoria alone. 1
2022–2025: National estimates suggest 1–2 million feral deer, with potential to double annually under ideal conditions. 1 2
We can clearly see what rangers, farmers and hunters have known for years: after decades of a small but growing number of feral deer in the wild, the 1980s marked the start of massive growth in their population. Victoria now hosts an ever-growing population of feral deer numbering well over a million animals and covering >50% of the state. This population explosion is what happens when invasive species are not promptly and effectively controlled and contained while they’re small in number. We now have a big problem!
🧠 Management Implications
Even with active control programs, the population’s high reproduction and survival rates make it difficult to suppress growth without sustained, coordinated efforts.
Their expansion poses significant risks to native vegetation, agriculture, and road safety, especially as they move into new habitats.
Carrying Capacity: Deer are impacting pastures, forcing farmers to reduce the numbers of livestock
Revegetation Planning: Areas with high deer density may need exclusion fencing or staged planting cycles.
Cull Justification: These metrics support economic and environmental arguments for sustained control.
🦌 Visual Resources You Can Explore
National Feral Deer Action Plan: Includes maps and projections of deer spread across Australia.
ABC Landline Feature: Offers visuals and interviews on deer population growth and harvesting efforts.
Invasive Species Council Report: Shows potential distribution maps and species-specific expansion zones.