Non-breeding Nazca booby adults exhibit an unusual and intense social attraction to non-
familial conspecific nestlings. Non-parental Adult Visitors (NAVs) seek out and approach
unguarded nestlings during daylight hours and display parental, aggressive, and/or sexual
behavior. In a striking parallel to the “cycle of violence” of human biology, degree of
victimization as a nestling is strongly correlated with frequency of future maltreatment
behavior exhibited as an adult. Here, we investigate candidates for permanent organization …