Same-sex pair bonding is an understudied area of research interest. In an early, small sample study, researchers have observed similar behavior in female-female parenting as with heterosexual pairs in the zoo greater flamingo (Phoenicopterus roseus). These early results could be illuminating with regard to the evolution of flamingo social behavior, same-sex pair bonds, and why pair bonds form in general. Image credit: Dhaval Vargiya, CC SA 4.0.