Are there documented cases of lesbianism in the animal kingdom?

Interesting question, and I hope this helps -

Female spotted hyena have hugely a extended clitoris (the first time I saw them, I was convinced it was a male!). The females of a pack routinely great each other by licking and nuzzling each other's clitoris. This is obviously social bonding behaviour, but is done regularly and voluntarily, so does this count as lesbian behaviour?

Also, as a kid I had lesbian rabbits! They were so desperate to mate, they would hump each other, so they definitely were!

Just found this 'news flash' - might answer your question!!

An intrepid team from the the University of Queensland will shortly make its way to Malaysia's central highlands to answer a question which has baffled science for centuries: is bovine lesbianism in domesticated cattle a stress reaction caused by environmental pressures?

Yes indeed, hot on the heels of the British revelations that sheep like happy, smiley people and pine for absent friends comes the earth-shattering possibility that cows' propensity to indulge in a bit of girl-on-girl is caused by a combination of "stress, and a selective domestication process which favoured outwardly sexual cows and the number of animals on heat in a small enclosure.

And then... Japanese macaques are ardent lesbians; the females enthusiastically mount each other. Bonobos, one of our closest primate relatives, are similar, except that their lesbian sexual encounters occur every two hours.

Then, of course, there are the boy animals..

Male big horn sheep live in what are often called "homosexual societies." They bond through genital licking and anal intercourse, which often ends in ejaculation. If a male sheep chooses to not have gay sex, it becomes a social outcast. Ironically, scientists call such straight-laced males "effeminate."

Giraffes have all-male orgies. So do bottlenose dolphins, killer whales, gray whales, and West Indian manatees. Bonobos, one of our closest primate relatives, are similar, except that their lesbian sexual encounters occur every two hours. Male bonobos engage in "penis fencing," which leads, surprisingly enough, to ejaculation. They also give each other genital massages.

Not exactly lesbianism. Cows often mount each other when sexually receptive. The bull sees this, thinks he has a rival, wanders over to see him off, realises his mistake and, relieved at not having to fight, stays to do the business. But thats just a cows way of attracting attention!

Where did you hear it being argued? You make it sound as if you were standing in the que in asda and some bloke and his mate were deep in conversation about animal homosexuality!

With respect I don't know much about animal homosexuality!

At London Zoo we used to have a pair of female griffon vultures that went through the courting rituals and were seen mating. A few days later thay both made nests and both laid eggs!

there have been documented sightings of femail chimpanzes and dolphins engaging in sexual activity for sure. unfortunately, in the past a lot of these 'incidents' went un-reported by field researchers or documentary makers because they felt that it was not something they could report.

however, it is true - not only does it occur in highly developed animals (primates/dolphins/humans), but also within plants (asexual reproduction)

I remember seeing this on TV about 2 sheep that were quite fond of one another.....and they would not mate with any female sheep. I don't recall them having sex but then again, it was years ago! check out this site:http://www.bidstrup.com/sodomy.htm

I have seen male Hyenas enagage in copulation on NGC

i dont know if it is documented but i have seen two male dogs sex each other

A group of gay lions is called a gay pride