Dynamic shifts in social network structure and composition within a breeding hybrid population

Area of Science:

• Ecology and Evolutionary Biology
• Behavioral Ecology
• Population Genetics

Background:

• Reproductive barriers like mating behavior and timing are crucial for species divergence but difficult to quantify in natural populations.
• Social network analysis offers a powerful framework for understanding the social context of hybridization and genetic exchange.
• Hybrid zones provide unique opportunities to study the interplay between social structure and gene flow.

Purpose of the Study:

• To investigate how social networks change during a breeding season in a hybrid population of California and Gambel's quail (Callipepla californica and Callipepla gambelii).
• To determine whether association rewiring or individual turnover drives network dynamics and influences reproductive isolation.
• To assess the relationship between social associations, genetic relatedness, and parentage patterns within the hybrid population.

Main Methods:

• Combined RFID tracking data, phenotypic information, and genomic data with social network analyses.
• Quantified network structure changes using ecological network methods, partitioning changes into association rewiring and individual turnover.
• Integrated genomic data (ancestry, relatedness, parentage) as node and edge attributes to link social and reproductive networks.

Main Results:

• Association rewiring, where individuals change social partners, was the primary driver of network structure changes, more so than new individuals entering the population.
• Phenotypic and genotypic assortment patterns were dynamic throughout the breeding season.
• Social networks showed random assortment by genetic ancestry, suggesting limited behavioral reproductive isolation. Stronger social associations, not genetic relatedness, predicted parentage.

Conclusions:

• Social network dynamics, particularly association rewiring, play a significant role in shaping gene flow within hybrid populations.
• The study highlights the utility of social network analysis for understanding the links between social context and genetic exchange in wild populations.
• Findings suggest that social interactions, rather than just genetic factors, influence reproductive outcomes and potentially species interactions in hybrid zones.