Lemur catta in small forest fragments: Which variables best predict population viability?

Area of Science:

• Primate ecology
• Conservation biology
• Habitat fragmentation

Background:

• Habitat fragmentation is a major threat to primate populations globally.
• Ring-tailed lemur (Lemur catta) populations in south-central Madagascar are increasingly confined to isolated forest fragments.

Purpose of the Study:

• To assess the population viability of ring-tailed lemurs in nine forest fragments of varying sizes.
• To identify ecological factors influencing population size and juvenile recruitment in fragmented habitats.

Main Methods:

• Utilized Poisson regression models to analyze the relationship between fragment size, food availability, and population dynamics.
• Quantified within-fragment food resources (Melia azedarach, Ficus spp.) and matrix resources.
• Assessed juvenile recruitment rates and potential for male dispersal.

Main Results:

• Population size and juvenile recruitment were strongly associated with fragment size and the abundance of key food resources.
• Fragment size was the primary predictor of juvenile recruitment when considering fragment size and food resources.
• While most fragments had low human disturbance, only a few supported male dispersal, indicating uncertain long-term viability.

Conclusions:

• Forest fragment size and food availability are critical for ring-tailed lemur persistence.
• Long-term survival is uncertain due to limited potential for male dispersal and varying levels of human disturbance.
• Conservation strategies must consider habitat connectivity and resource management in fragmented landscapes.