Emu's Role Reversal

The roles are reversed when it comes to breeding for emus.  

 Picture from Carolina Emu

Unlike most other animals, it is the female emu who must compete for a mate.  Once the male has chosen a mate, the two will breed frequently, with the female laying up to 20 eggs during the summer months.  Also opposite from the traditional gender roles, it's the male's job to incubate the eggs after they have been laid by the female, who will leave the nest to find another mate.

Mating Habits Of The Red-sided Garter Snake

Red-sided garter snakes have quite an unusual time during mating season. Every spring, tens of thousands of these snakes emerge from hibernation and engage in mating balls (like orgies). The males emerge first, waiting for the females. Whenever a female appears, the males surround her, rolling and writhing until one finally mates with her; but often multiple males will take the opportunity.

Even weirder, is that some of the male snakes can create the same female pheromone (a chemical released to attract males). These are known as “she-male” snakes, and they often fool other males into trying to mate with them. However, the reason for why they do this is still unknown.