Adaptive Harvest Management for game duck hunting in Victoria

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.