I think they use their bright colours to attract females.
It may not be used to attract a mate, but male squids do have one tentacle which also serves as a sexual appendage.
A male bird shows bright feathers to attract a mate. What type of behavior is this?
they do an elaborate song and dance routine to attract the female and then mate much as other birds do when she accepts him.
It doesn't normally happen but has been known, and cygnets have been produced.
Usually the male is the one to go homosexual, but yes they can. They will either steal another mates eggs or have a threesome with a male and then chase him away.
It is the male that is the more colorful. They have to attract the mate.
if a swans mate dies, it will either let himself die, or find another mate. but that only happens on rare occasions. I have a personal experience myself, i live on a lake and there are only two swans and ones mate died after a serious coyote attack. The male swan is in a dreadful mourn and might die soon, if we don't get another female swan.
Male polar bears usually fight with another male to prove to the female that he is the strongest
The Goliath frog is assumed to be the world's largest species of frog. The male typically builds a nest to attract a mate, but the males will also generally fight one another to win a mate's attention.
The male Bowerbird uses treasures to attract females.
Courtship Behavior