Scientists form general theory of bird homosexuality鸟儿也搞同性恋

Scientists have long speculated gleefully about animal homosexuality.
Now an Australian researcher has developed a theory to explain homosexuality in birds. More than 100 bird species engage in some sort of homosexual behavior, which ranges from casual sex to child-rearing partnerships.
Geoff MacFarlane, of the University of Newcastle in Australia, has found that the avian gender that spends less time raising hatchlings is the gender more likely to indulge homosexual desires. In bird species where men slept around and females raised children, males were more likely to engage in same-sex behavior. In bird species where both sexes looked after babies, females were more likely to turn their attentions towards other females.
In less-monogamous bird species, the abundance of available partners means that homosexual behavior is less stigmatized; birds that have had same-sex flings appear to have as much reproductive success as those that have not.
A report on the subject from LiveScience also states that, for some birds, "homosexual alliances may even be adaptive, helping individuals defend territories, advance their social status, or get help with parental care."
