Human sexuality is a rich and varied tapestry, however the sexuality of other animals is enough to make that of Christian Grey seem dry and vanilla. Many animals employ an arsenal of apparatus, extensions and accessories all with the aim of maximising their success in reproduction, in some cases at the expense of their partner's well-being.
One extreme example of this arms race would be the sexual behaviour of the Argentine Lake Duck (Oxyura vittata). Their bristly, corkscrew-shaped penises become erect in an explosive manner similar to a party popper. They also have the largest penises in relation to body size of all vertebrates. One specimen of Argentine Lake Duck was found to have a remarkable 42.5cm long penis with a body length of only 20cm! These ‘elaborate penises’ have evolved to remove competitors sperm from the female’s vagina. The poor females who are continually harassed throughout the breeding season have evolved an ingenious mechanism to prevent undesirable males from mating with them. Researchers at Yale University and the University of Sheffield discovered that female ducks possess ‘cryptic vaginas’ with false passages and a screw-like spiral which threads the opposite way to the male’s penis. This spiral can be tightened, cock-blocking the unwanted males and allowing the female to have more influence over who fathers her children.
However, not all animals are such inconsiderate lovers. Researchers at the Slovenian Academy of Sciences and Arts have observed in Darwin’s Bark Spider (Caerostris darwini) a courtship behaviour known as ‘oral lubrication’. This behaviour occurs before mating and involves the male spider lubricating the female’s genitals with digestive juices secreted through the fangs. However, this creepy-crawly cunnilingus is not merely an act of sexual generosity; it is suggested that oral lubrication helps to relax the female, making it less likely that she eats the much smaller male after mating. As well as oral sex, these kinky critters are also partial to a bit of BDSM. With a silk ten times stronger than Kevlar, males have been observed to tie up females in order to restrict their movement during copulation in a behaviour known as ‘mate binding’.
Unlike Darwin’s Bark Spider, male Redback Spiders (Latrodectus hasseltii) actively encourage females to consume their flesh during mating by doing a summersault directly into the waiting jaws of the female while leaving his sexual organs or ‘palps’ in one of the female’s sperm storage organs. This act of sexual suicide benefits the male in two ways. Firstly, it allows the male to continue to mate with the female while she is busy eating, which allows the male to fertilise more of her eggs. The second benefit is that this behaviour seems to make the female less likely to mate with other males. It is suggested that chemicals in the male’s flesh may reduce the female’s desire to mate with other males.
Flatworms (Platyhelminthes) are hermaphrodites, which means they both carry both sets of sexual organs. To decide who is to take on the roles of male and female they engage in behaviour known as ‘penis fencing’ where the two flatworms have what is essentially a penis sword fight. The winner of this standoff gets to be the male and impregnate the other flatworm. The loser must bear the cost of raising the offspring and immediately begins feeding to raise the resources needed to make eggs.
Being male is not as desirable in all species. The Triplewart Seadevil (Cryptopsaras couesii) is a type of Anglerfish that uses a bioluminescent lure to attract its prey. The males of this species are 30 times smaller than the females and have a stunted digestive system. In order to survive, they must attach themselves to the females vent using hollow fang like teeth. From this point on they share the female’s bloodstream, shriveling to nothing more than a wart-like, sperm–producing appendage. Talk about being whipped!
Finally, however, there is no animal more dedicated to sex than the male Antechinus; a small, rodent-like marsupial native to Australia. This crazed little critter literally mates itself to death in its first breeding season, a period of only two weeks. It spends this time constantly searching for and with females until it keels over and dies of stress and exhaustion, a sickly gangrenous shadow of its former self.
...But what an amazing way to go.