Hunting

Adaptive Harvest Management for game duck hunting in Victoria

The Victorian Government has adopted adaptive harvest management as a more transparent and rigorous method for regulating the recreational harvest of game ducks in Victoria.

Adaptive Harvest Management (AHM) is an evidence-based process for setting game duck season arrangements. It involves using information to select the best approach to achieving a management objective, implementing management actions, measuring the response, adjusting the approach as required, and then repeating the process. It is a process of learning by doing.

The policy settings to inform AHM are detailed in the Victorian Game Duck Harvest Strategy. The Strategy includes the management objective, proportional harvest target and approach to settings to regulate harvest.

First year of implementation summary

In 2025, the Victorian Game Duck Harvest Strategy (the Strategy) was released by the Victorian Government. It commits to an adaptive harvest management (AHM) approach for setting the annual duck hunting season arrangements.

The Strategy sets the parameters under which the seasonal arrangements will be determined, including hunting methods and season timing and length, which is from the third Wednesday in March to the second Monday in June each year over the Strategy’s three-year life.

The Strategy has also set the proportional harvest of game ducks conservatively at 10 per cent of the total Victorian game duck population (the Strategy recognises that the actual quota percentage may be slightly higher to achieve the nearest bag limit whole number). Previous population modelling has shown that key game duck species can be harvested sustainably at up to 20 per cent of the total population and factors in climate variation and wounding losses. See Conservation and Sustainable Harvest Models for Game Duck Species (PDF 2107.37 KB) by Dr Thomase Prowse for more information.

2025 duck season

The game duck population estimate in Spring of 2024 was approximately 4 million birds.  A 10 per cent proportional harvest meant that the 2025 season seasonal harvest quota was 400,500 birds.

The modelled bag limit to achieve the proportional harvest of at least 10 per cent (10.4 per cent) was nine ducks per day. The actual harvest of game ducks in Victoria in 2025 was 12.2 per cent of the total Victorian game duck population.

As part of the continuous improvement process of AHM, the modelling and monitoring program is independently reviewed by an expert panel who provides advice to the GMA. Based on this advice several refinements have been tested and applied to the data collection and statistical and modelling processes.  

2026 duck season

New explanatory variables were tested in the abundance model, including total rainfall in the vicinity of each waterbody (5km x 5km grid cell) over the previous three months and updated waterbody classifications. The abundance estimate for game ducks in Victoria in Spring 2025 was 4.9 million game ducks.

Variations to the bag model were also explored to improve performance by testing the predicted vs actual result in 2025. A revised model including replacing total number of licence holders with total number of hunting days provided a superior fit to harvest data and was applied for the 2026 model.

The modelled bag limit to achieve the proportional harvest is nine game ducks per day.

Victorian Game Duck Harvest Strategy Preliminary results from the 2025 survey of game ducks in Victoria and recommendations for seasonal arrangements GMA recommendation on the 2026 duck season bag limit

Implementing Adaptive Harvest Management for duck hunting in Victoria requires:

  1. Establishing the harvest objective/s
  1. Using information from the monitoring and modelling program to set an annual daily bag limit to achieve the harvest objective
  1. Implementing the daily bag limit for that season
  1. Monitoring the total seasonal harvest level achieved by the daily bag limit
  1. Evaluating the performance of the daily bag limit and modelling approach in achieving an annual sustainable harvest quota
  1. Revising the approach as required.

Adaptive Harvest Management Cycle

The process for setting annual duck season arrangements

An outline of the process for setting duck season arrangements is provided in the table below.

The Victorian Government sets the harvest objectives in its Game Duck Harvest Strategy. This includes a proportional harvest level which is expressed as a percentage of the total Victorian game duck population. That percentage of the total population becomes the harvest quota for the season. Wounding losses will be factored into the proportional harvest level.

The GMA gathers data on previous harvests (from surveying hunters) and total game duck abundance in Victoria.

Key modelling inputs:

  • Victoria game duck abundance survey
  • Habitat availability, using satellite imagery to determine the water in the landscape and extrapolating to determine available habitat
  • Harvest and hunting metrics, such as total seasonal harvests, seasonal arrangements and the total number of licensed hunters.

Through game duck population modelling, the estimated total abundance of game ducks is determined. The percentage proportional harvest is applied to the total abundance to identify the sustainable proportion of the population that can be harvested (i.e. the seasonal quota).

Using the harvest model, the GMA determines the daily bag limit that would achieve the seasonal quota.

Key modelling inputs:

  • Estimated game duck abundance for Victoria (as per the population modelling)
  • Past seasonal arrangements
  • Past total seasonal harvests
  • The number of licensed duck hunters

The GMA provides advice on the daily bag limit to the Victorian Government.

The DEECA and the DJSIR also provide advice to the Victorian Government.

Seasonal arrangements are set out in the Wildlife (Game) Regulations 2024. However, the Minister for Outdoor Recreation and the Minister for Environment have the power to jointly make changes to season arrangements to ensure that hunting remains sustainable, responsible and safe.

The responsible Ministers determine the arrangements for the forthcoming season.

Duck hunting season arrangements remain as per the Wildlife (Game) Regulations 2024 or are altered by the Ministers.

Expert panel reviews the approach

To ensure that GMA can fulfill its responsibility of providing robust advice on how to achieve the government’s harvest objectives, the GMA has established a technical expert panel to provide independent advice on the monitoring and modelling program.

The panel is made up of three members who collectively have expertise in:

  • wildlife ecology
  • population modelling
  • quantitative methods
  • applied statistics.

The expert panel will provide annual advice on:

  • the design and operation of the monitoring and modelling program to achieve the government’s stated game duck harvest objectives
  • ways to improve the monitoring and modelling program within available resources
  • any other matters regarding the sustainable harvest of game ducks in Victoria requested by the GMA.

Following the review, the expert panel will provide recommendations to the GMA for consideration and implementation the following year.

+ Expand all- Collapse all

The development of AHM has a long history in Victoria and was first considered in 2002. Implementing AHM for duck hunting in Victoria is a key commitment in the Victorian Government’s Sustainable Hunting Action Plan (SHAP) 2016 – 2020 and in SHAP 2021-2024.

The Victorian Government has committed to implementing AHM as a more robust, transparent and evidence-based approach to setting annual duck season arrangements.

This commitment follows a detailed exploration of the benefits of using science-based population models to help improve evidence- based decision-making related to regulatory settings for annual game duck hunting seasons.

The GMA will deliver the monitoring and modelling program to advise government annually on how to achieve its harvest objective. The harvest objective will be determined in the Victorian Government’s Game Duck Harvest Strategy, which is currently being developed.

Each year, the GMA monitors game duck populations and habitat extent. The GMA also collects data on hunter behaviour and harvest metrics, including the total seasonal harvest. All data collected by the GMA is available at Duck Research.

Over time, more information will become available for the Adaptive Harvest Management modelling program. The models will ‘adapt’ through learning about Victorian-specific contexts, including habitat extent, game duck population dynamics, hunter behaviours and responses to management actions.

The GMA will also conduct research into the movement and survivorship of game ducks to help us to understand the response of ducks to environmental drivers. This will allow development of a modelling approach to estimate changes in the Victorian population size between the surveys and the harvest season, potentially incorporating both dispersal and natural mortality over this period.

Victorian duck hunters appear to apply a fixed level of effort each season, regardless of environmental conditions and season arrangements.

Based on this, season length does not appear to be a strong lever to regulate total harvest, unless season length is drastically reduced.

Therefore, modelling is used to provide advice on the daily bag limit, to achieve the seasonal harvest quota, rather than recommending changes to season length. This approach may change as we begin to understand how seasonal arrangements influence the season’s harvest and whether additional controls are required to regulate the take.

The open season is timed to avoid periods of vulnerability for game ducks, such as breeding, periods of food shortage and cold temperatures.

Evidence suggests that Victorian duck hunters appear to operate to a fixed level of effort each season, irrespective of environmental or regulatory settings and that bag limits are a more effective way to regulate harvest.

Adaptive Harvest Management is about continual review and improvement, and the GMA is committed to using the best available science to ensure the sustainability of duck hunting in Victoria.

To assist in ensuring the monitoring and modelling program remains contemporary and fit for purpose, an AHM Monitoring and Modelling Technical Expert Review Panel has been established. The panel will provide independent expert advice to the GMA on:

  • the design and operation of the monitoring and modelling program to achieve the government’s stated game duck harvest objectives
  • ways to improve the monitoring and modelling program within available resources
  • any other matters regarding the sustainable harvest of game ducks in Victoria requested by the GMA.

The expert panel will meet after release of the game duck abundance and recommended bag limit technical report to consider the performance of the monitoring and modelling program, and any recommendations for improvement.

Adaptive Harvest Management presentation 2024

This video presentation from Game Management Authority (GMA) Chief Executive Officer, Graeme Ford and Director of Strategy and Research, Simon Toop explains the purpose of AHM and how it will be used to determine duck hunting season arrangements.

Previous duck season considerations