A new method for identifying rapid decline dynamics in wild vertebrate populations

Area of Science:

• Ecology
• Conservation Biology
• Biodiversity Science

Background:

• Tracking wildlife population trends is crucial for assessing biodiversity change.
• Human pressures can cause rapid shifts in wildlife population dynamics.
• Distinguishing human-induced declines from natural fluctuations is essential for effective conservation.

Purpose of the Study:

• To test associations between human pressures and wildlife population decline curves.
• To develop a method for differentiating decline trajectories from natural population fluctuations.
• To assess the reliability of using decline curves for threat attribution and conservation prioritization.

Main Methods:

• Simulated mammalian population time-series under various human pressure types and intensities.
• Analyzed population trend concavity and fitted algebraic functions to identify distinct decline dynamics.
• Tested method robustness with environmental stochasticity and varying data quality.
• Applied the developed method to 124 real-world wildlife population time-series.

Main Results:

• Significant distinctions in population dynamics were identified based on human pressure types.
• The method successfully attributed decline dynamics to broad categories of pressure.
• Population decline curves reliably identified increasing pressure over time, even with poor data quality.
• Detailed threat attribution was not feasible, but broad categories were discernible.

Conclusions:

• Wildlife population decline curves can discern broad categories of threats and identify increasing pressure.
• The method is a cost-effective tool for prioritizing conservation actions.
• This approach enhances biodiversity change assessment by linking population trends to human impacts.