The investigation of prosocial behavior is of particular interest from an evolutionary perspective. Comparisons of prosociality across non-human animal species have, however, so far largely focused on primates, and their interpretation is hampered by the diversity of paradigms and procedures used.
Here, we present the first systematic comparison of prosocial behavior across multiple species in a taxonomic group outside the primate order, namely the bird family Corvidae. We measured prosociality in eight corvid species, which vary in the expression of cooperative breeding and colonial nesting. We show that cooperative breeding is positively associated with prosocial behavior across species. Also, colonial nesting is associated with a stronger propensity for prosocial behavior, but only in males.
The combined results of our study strongly suggest that both cooperative breeding and colonial nesting, which may both rely on heightened social tolerance at the nest, are likely evolutionary pathways to prosocial behavior in corvids.
The investigation of prosocial behavior i. Humans show high levels of prosocial behaviors from an early age on Silk and House, , although their expression and developmental trajectories are subject to cross-cultural and societal variation House et al. The importance of prosociality for human interactions has inspired comparative studies on the evolutionary origin of this trait.
The majority of experimental studies in non-human animals have focused on primates for a review, see Marshall-Pescini et al. Nevertheless, not all tested species have shown prosocial tendencies e. Unfortunately, however, comparisons of prosociality across species have been hampered by the diversity of paradigms and procedures used Marshall-Pescini et al.
