A meta-analytic review of corridor effectiveness

Area of Science:

• Ecology
• Conservation Biology
• Landscape Ecology

Background:

• Habitat fragmentation is a major threat to biodiversity.
• The efficacy of wildlife corridors in facilitating species movement is debated.
• Existing research on corridor effectiveness yields mixed results.

Purpose of the Study:

• To determine if wildlife corridors increase species movement between habitat fragments.
• To assess how corridor effectiveness varies across different taxa (e.g., plants, invertebrates, vertebrates, birds).
• To evaluate the impact of experimental design, including recent methodological advances and the distinction between natural and manipulated corridors, on findings.

Main Methods:

• A meta-analysis of 78 experiments from 35 studies was conducted.
• A hierarchical Bayesian model was employed to account for data dependencies.
• Studies were analyzed to compare movement in connected versus unconnected habitat patches.

Main Results:

• Corridors significantly increased species movement between habitat patches by approximately 50%.
• Corridor effectiveness was higher for invertebrates, non-avian vertebrates, and plants compared to birds.
• Natural corridors facilitated more movement than manipulated corridors, especially when controlling for distance.

Conclusions:

• Wildlife corridors are effective tools for enhancing species movement in fragmented landscapes.
• Conservation efforts focused on maintaining and creating corridors are valuable and supported by empirical evidence.
• Understanding the influence of taxa and experimental design is crucial for optimizing corridor function.