Identifying target reference points for harvesting assessment-limited wildlife populations: a case study

Area of Science:

• Wildlife ecology and management
• Population dynamics
• Sustainable resource management

Background:

• Sustainable harvest of terrestrial vertebrates is difficult due to uncertain population dynamics and limited data.
• Lack of monitoring infrastructure hinders rigorous population assessment and state-dependent management.
• Existing reference points for management are often ambiguous, failing to account for uncertainty and competing objectives.

Purpose of the Study:

• To develop an approach for creating unambiguous target reference points for assessment-limited species.
• To apply this approach to determine optimal harvest rates for Wild Turkey (Meleagris gallopavo) populations.
• To address challenges posed by uncertain population and harvest dynamics in wildlife management.

Main Methods:

• Utilized structured decision-making (SDM) to develop unambiguous target reference points.
• Employed simulation and decision analyses to identify optimal and robust harvest rates.
• Incorporated uncertainty in population and harvest parameters into the decision framework.

Main Results:

• Identified specific harvest rates that optimize explicit management objectives under uncertainty.
• Demonstrated that interacting population and harvest parameters critically influence target harvest rates for Wild Turkeys.
• Developed more conservative target reference points by formally considering a range of plausible parameter values.

Conclusions:

• The structured decision-making framework provides a robust method for setting unambiguous harvest targets for assessment-limited wildlife.
• Acknowledging structural uncertainty in system dynamics leads to more reliable management reference points.
• This approach can be extended to other assessment-limited wildlife populations facing similar management challenges.