Digest: Cooperative breeding strategies in birds are shaped by avian predator richness.

Despite their prevalence, family-living and cooperative breeding in birds have received little examination as to how and why they vary across species. Investigating the evolution of these social systems, Bliard et al. (2024) found that the presence of avian predators is associated with birds' social systems, with increases in predator presence corresponding to multiple shifts from non-family-living to cooperative breeding. Phylogenetic comparative analyses indicate that factors outside the breeding season can be selected for family-living and cooperative breeding.