Fine-scale genetic structure analyses reveal dispersal patterns in a critically endangered primate, Trachypithecus...

Area of Science:

• Primate behavioral ecology
• Population genetics
• Conservation biology

Background:

• Dispersal patterns significantly influence population genetic structure and social dynamics in social species.
• Primates display diverse dispersal strategies, but detailed studies are often limited by observational constraints.
• Understanding dispersal is crucial for conserving endangered species like the white-headed langur.

Purpose of the Study:

• To investigate the dispersal patterns and population genetic structure of the endangered white-headed langur (Trachypithecus leucocephalus).
• To determine if sex-biased dispersal occurs in this colobine species.
• To provide genetic data for informing conservation strategies.

Main Methods:

• Non-invasive fecal sample collection from 41 social groups across the white-headed langur's range.
• Individual identification and genotyping using microsatellite loci and a sex-specific marker.
• Mitochondrial DNA (mtDNA) hypervariable region I (HVRI) sequencing for phylogenetic analysis.
• Genetic assignment tests to infer first-generation migrants.

Main Results:

• Higher intragroup genetic relatedness observed in both male and female langurs.
• Females in the Fusui population showed isolation-by-distance, unlike males.
• Spatial autocorrelation revealed high within-group relatedness, with females showing clustering at 0.5 km.
• Genetic assignment confirmed random dispersal in males and localized dispersal in females.

Conclusions:

• The study provides the first genetic evidence of sex-biased dispersal in white-headed langurs.
• Male dispersal appears random, while female dispersal is likely restricted to adjacent groups.
• These findings are vital for effective management and conservation of Trachypithecus leucocephalus populations.