The sex life of a fruit fly

Birds do it, bees do it, even educated fleas do it - but some of them do it in extremely strange ways. Gideon Defoe takes a look at the wild world of sex in the animal kingdom

FRUIT FLY

Scientific name: Drosophila bifurca
Size: 2.5-4mm
Distribution: All tropical regions
Diet: Rotting fruit

Mind control is usually a terrible way to pick up a girl. More often than not, you'll just wind up with a slap. A male fruit fly sensibly leaves the mind control to their sperm, which contains a cocktail of chemicals that helps to make the fly's mate more compliant and lower her libido for other males. He also goes for quality over quantity, with a single, massive 5cm-long sperm, 20 times longer than himself, which takes three days to make. Despite repeated attempts, mainly by teenagers, a human male has never managed to produce an individual sperm bigger than his own body. Which is a relief.

ELEPHANT

Scientific name: Loxodonta africana
Size: 4m, 7,500kg
Distribution: Africa, Asia
Diet: Grass, leaves, roots, twigs

During the mating season, male elephants bellow at other males, their testosterone levels shoot up to 50 times higher than normal and each loses up to 350 litres of urine every day. On the plus side, he has the biggest penis of any land animal - and it has to be, as the female's vagina isn't beneath her tail but much further down. Once the sex is over, the female's relatives are comically pleased with her - in "mating pandemonium" her entire family rushes over, shouting, trumpeting and defecating everywhere.

RHINOCEROS

Scientific name: Diceros bicornis
Size: Up to 2.2 tonnes
Distribution: Africa, Asia
Diet: Plants, small foliage

Hey, ladies, why not try the no-nonsense approach to finding out whether your man is worth putting out for? It's easy. Stand at one end of your hallway and get him to stand at the other. Now run really fast at each other until you collide with a big, clanging head-butt. To get the full effect, it helps if you each weigh about three tonnes and can reach speeds of 30mph. If your man is lying unconscious on the floor, he's probably not worth bothering with. But if he's still on his feet after you've repeated the process a few times, he could be the one. This kind of effort is why male rhinos in safari parks seem to prefer sex with Renault Lagunas.

BONOBO (PYGMY CHIMPANZEE)

Scientific name: Pan paniscus
Size: 70-80cm, 27-61kg
Distribution: The Congo river basin
Diet: Fruits, seeds, insects (rarely)

For years it was thought that only humans engaged in face-to-face sex. But at least one other creature enjoys frontal intercourse - our closest cousin, the bonobo. It is also the only other animal that uses tongues while kissing. Sex plays an important role in resolving disputes and maintaining social cohesion. Bonobo societies get along because they're always getting it on with each other. In any combination. Girls rub clitorises. Boys rub rumps. They engage in fellatio and mutual masturbation. The male will alter the speed and intensity of his thrusting based on the facial expression of the female. Where other animals get into fights over food, bonobos have sex. We could learn a lot from them.

FRIGATE BIRD

Scientific name: Fregata magnificens
Size: 2.5m wingspan, 1.5kg
Diet: Fish, small turtles

It can take the male frigate bird 20 minutes to inflate the huge red balloon dangling from its neck. Females inspect who has the biggest and shiniest balloon, and have sex with him. During sex the male, rather sweetly, put his wings over the female's eyes to make sure she doesn't get distracted by any passing male with a nice balloon. The problem is that sharp beaks and big balloons are a really stupid combination. Rival males do their best to pop others' balloons - which is disastrous, as once your balloon is burst you're never going to get a girl. You're doomed to spend the rest of your life wandering around looking a bit sad with a shrivelled-up piece of skin hanging off your chin.

GIRAFFE

Scientific name: Giraffa camelopardalis
Size: 5-5.5m, up to 900kg
Distribution: Africa
Diet: Leaves, twigs

Evolution has played a dirty trick on the male giraffe by forcing him to pump blood around his body at twice the pressure of any other animal just get it up his neck and into his brain. So he's only ever interested in sex if there's a good chance the female will get pregnant. If he reckons it's the right sort of time, he'll give her a nudge on the bum with his head. This usually has the effect of making her urinate. Then he laps up her urine and swills it round his mouth for a bit. Having used his sensitive palate to detect whether or not she's fertile, he'll try to mount her. Except that females aren't much interested in sex, so often, halfway through, she'll wander off, leaving him almost falling over his spindly legs.

PIG

Scientific name: Sus scrofa
Size: 90-150cm
Distribution: Global
Diet: Almost anything

Pigs have a long, slender corkscrew penis with a hole in the side, out of which they ejaculate an entire pint of semen, the last few ounces of which is like a thick, custard to keep it all from falling out. Like a lot of creatures, the odd penis shape may have something to do with preventing hybridisation - the more unique the penis, the more likely it is to only fit one kind of vagina. This is a good thing, because hybrids are generally useless and infertile. The exception to this would be something that was half eagle and half shark, which would rule.

ANGLER FISH

Scientific name: Edriolychnus schmidti
Size: Female 20cm, males 3cm
Distribution: Atlantic, Pacific, Indian oceans
Diet: Fish, larger invertebrates

The bleak ocean depths is to blame for the angler fish's unconventional sex life. Even with the headlamp the girls have, it's difficult to meet down there in the gloom, so when the tiny male meets the huge female he does his best to never let go. He takes a big bite out of her side, then hangs on - for so long his jaw fuses with her skin. This gets round the problem of his not having a digestive system, as he starts to live off her blood supply. Over time he wastes away until he's just a pair of gonads stuck to her side, supplying sperm as and when required. A creature that mates for life. Isn't that sweet?

THE ARGENTINE LAKE DUCK

Scientific name: Oxyura vittata
Size: 40cm, 640g
Distribution: Argentinian lakes
Diet: Seeds, plant remains, small invertebrates

Most male birds don't have penises - they've dispensed of them in favour of the slightly rubbish "brief pressing together of genital orifices". But not only has the Argentine lake duck kept his, he's become embroiled in a daft sexual arms race. This has left a not very big duck with an organ up to 41cm long. Sexual selection theory would put this down to female choice, although scientists at the University of Alaska think it could also be a result of intense sperm competition. Or it may be used in aggressive displays to intimidate rivals. And it's been suggested that they use their penises to lasso reluctant females.

How Animals Have Sex by Gideon Defoe is published by Weidenfeld & Nicolson at £9.99. To order your copy with free P&P call Independent Books Direct on 08700 798 897, or order online at www.independentbooksdirect.co.uk