researchers found that when zebra finches form same-sex pairings, they are just as devoted to their partners as they would be in an opposite-sex pairing. zebra finches are monogamous, and same-sex pairs displayed the same nesting, preening, and courtship behaviors as opposite-sex pairs. although same sex pairs cannot reproduce, there are survival advantages to having a mate, regardless of sex. when researchers added in ‘extra’ females to the groups of finches, the finches still chose to stay with their same-sex partners.