Sadly, I'd rather be ignorant, than put that much effort into it.

I think when most non-biologists / non-psychologists talk about homosexuality they mean same-sex sexual partners [I should probably flash a parent-alert, about now]. And as male-oriented as our culture is, it's all about the orgasm. Likewise [trying not to be graphic here] the method of achieving that orgasm may be pertinent to whether all folks would agree it is homosexual behavior.

I thought it was still largely true that there are only rare instances of this sort of behavior (by the narrow definition I described in the last paragraph) among animals in the wild. It is *very* common for animals who do not - or only rarely - exhibit such behaviors in the wild, to do so in zoos. This is what I was referring to.

I don't know about any studies that attempted to relate crowdedness as a factor in human homosexuality, as you referred to. Though I'd be surprised to find that none had been done.