Cooperative Breeding and Same-Sex Pairs
Cooperative breeding, in which an animal assists in caring for offspring not its own, is often found in nature. But researchers in Hawaii have recently discovered a case involving long-term pairs of unrelated birds of the same sex.
Lindsay C. Young of the University of Hawaii and colleagues studied a colony of Laysan albatrosses on Oahu from 2004 to 2007. These birds are monogamous, and both parents participate in raising a single hatchling. The researchers reported in Biology Letters that nearly one-third of the 125 pairs consisted of two unrelated females, and half of these stayed together for the duration of the study.
The researchers note that for female-female pairing like this to occur, usually there has to be a surplus of females in the population. For same-sex pairing to persist, the researchers say, both females should have opportunities to reproduce. They found evidence for that: for some pairs that produced chicks in more than one year of the study, at least one was from each female.
Male and female He made them, but female and female raise the chicks.
