plus we are animals governed by the same instincts and desires as they are. we think we are seperate but many animals and birds have weird dances and decorate themselves to attract a mate, or gather a bunch of twigs and rocks and build a hut to attract a mate (their version of materialism). and dont forget the buck with the biggest horns gets to mate or have his harem..so female animals are often very picky and will pick a healthy, strong, attractive or brightly colored mate. in the wild, they arent looking for wit, humor, spontinaity or career ambition.
so yeah, i think looks are vitally important, then the other factors come into play..personality, intelligence, humor, interests...posture even. so we can drool over some hottie, but then find him utterly boring, while we can have no initial interest in someone not our type, and then get to know them and develope a bond.
**however, i am not so sure about gay animals. i know researchers in the field who witness "gay animals" - usually a bunch of males who live together for protection and who are unable to mate with a herd of females who are dominted by one male who fights them off. they will "mount" each other and show affection, etc. but i am not sure if they go out of their way to fight, or impress each other to win over one male over the other, or if they think one is hotter than another..who knows.