I don't think that we can draw any conclusions from animals. The way that animals socially interact is so radically different from they way that humans do that I think that it would only matter for very closely related species - apes for example.
The wikipedia article strikes me as suspicious. It sounds like they're really not saying very much, but trying to insist that homosexuality is both biological and evolutionarily beneficial because they're supposed to say that.
Anyway, on another thread I posted a link to this interesting twin study with more substantial conclusions:
www.sciencemag.org
Homosexuality is primarily non-biological for both men and women, but biology does play a role. Biology plays about twice as big a role in men than women for determining sexual orientation.