Defining practical and robust study designs for interventions targeted at terrestrial mammalian predators

Area of Science:

• Conservation Biology
• Wildlife Management
• Ecology

Background:

• Human-mammalian predator conflicts are increasing globally, posing challenges for conservation and livelihoods.
• Effective conflict mitigation relies on evidence from robust study designs, but current practices are unclear.
• There's a need to understand study design trends and improve best practices for predator-targeted interventions.

Purpose of the Study:

• To examine the evolution of study designs used in human-predator conflict interventions.
• To assess the relationship between study designs and factors like intervention type, predator species, and country.
• To identify limitations and applicability of different study designs for future research.

Main Methods:

• Analysis of 434 cases from 244 studies published between 1955 and 2020.
• Application of multinomial regression modeling to track changes in study design usage.
• Categorization of interventions into types: aversion, husbandry, mixed, invasive, lethal, and noninvasive management.

Main Results:

• Study design choice was primarily related to intervention type, not other factors.
• Less reliable designs (before-after and control-impact) were most common (47.7% and 38.2%) and increased over time.
• Robust designs like randomized controlled trials (5.3%) and crossover designs (1.4%) remained infrequent.

Conclusions:

• The prevalence of less rigorous study designs in human-predator conflict research is a concern.
• Before-after-control-impact designs offer broad applicability for predator interventions.
• Randomized controlled trials and crossover designs, while robust, have limitations in practical application for certain interventions.