Swans
Blue-Footed Boobies
These famous blue-footed birds do a dance when it's time to mate. The male blue-footed booby shows off his webbed feet to a potential female partner. The more pigmented his feet are, the better his chances are at mating with her. The vivid color indicates his ability to acquire food—so the brighter, the better. He displays his feet in an elaborate high-stepping walk. His dance also includes a wing display and an upward beak tilt, which the female hopefully reciprocates. Once she chooses a mate, the two form a monogamous pair and reproduce.
Betta Fish
When a male betta fish senses a female and is ready to mate, he builds a bubble nest. He gulps down surface oxygen and releases it underwater as bubbles. Once the bubble nest is ready, he relentlessly pursues the female. If she resists going into his bubble nest, the male violently forces her into it. He chases and bites her, and she may be visibly injured by the time she enters the bubble nest. After mating and producing her eggs, the male chases the female out of the bubble nest if she has not already left on her own. The male stays with the eggs and guards them until they hatch.
Sloths
The female sloth lets it be known that she is ready to breed by literally screaming for a mate. When in heat, she screams to attract males to her. The male follows the sounds of her yells and sometimes fights with other males to win the female's attention. Neither the male nor the female are monogamous in their mating. Both take multiple partners, with the female giving birth to one child at a time.
Peacocks
Peacocks flaunt their feathers to gain attention from peahens. As part of their courtship ritual, peacocks show off their plumage and fan out their feathers. Every peacock's tail has its own distinct color patterns and "eyespots." The female studies the number of eyespots and the size of the peacock's tail when making her decision. Bigger isn't always better, though. Some females are turned off by overly large tails with too many flashy eyespots. Particularly attractive males have a "harem" of several peahens, all of which are enticed by his spectacular tail.
Frogs
Female frogs choose a mate in many different ways. They can be attracted to his appearance, nest-building abilities or just his close proximity. However, the main method is the call of the male frog. When he is trying to attract a female, the male of many different frog species "sings" and sends out a mating call. For some species, if another male responds to his call, the two wrestle with each other. The victor, having proven himself to be the stronger contender, is then able to mate with the female.
Penguins
The male of some penguin species, like the gentoo and adelie penguins, presents the female with a "perfect pebble" as a part of their courtship. He spends hours searching to find the right one and fights other males for it. He then presents it to his chosen female, and she adds it to the nest if she accepts the gift. This "pebble proposal" finds penguins their lifetime mates, as many species are monogamous. However, female penguins choose another male if their partner doesn't appear during mating season.
