Conserving large carnivores: dollars and fence

Area of Science:

• Conservation Biology
• Wildlife Management

Background:

• Contrasting conservation strategies: landscape approaches vs. physical separation for wildlife management.
• Limited empirical data comparing the effectiveness of these approaches.

Discussion:

• African lion population densities and trends analyzed across 42 sites in 11 countries.
• Comparison of management practices: fenced reserves versus unfenced areas.

Key Insights:

• Fenced reserves maintain lion populations closer to carrying capacity than unfenced areas.
• Fenced reserves achieve 80% of potential lion densities at $500/km² annually.
• Unfenced populations require over $2000/km² to reach half potential densities and are sensitive to human population density.

Outlook:

• Lions in fenced reserves are primarily limited by density dependence.
• Unfenced lion populations face significant threats from density-independent factors and human proximity.
• Nearly 50% of unfenced lion populations may face extinction in the next 20-40 years without intervention.