Love and other animals

Like the male antechinus mouse, the oversexed often fail to find love
antechinus mouse
Staying power: the female antechinus mouse with her young. Photograph: Jean Paul Ferrero/ARDEA

At just 11 months, the male antechinus mouse reaches sexual maturity. He searches his territory every night, hoping to satisfy his voracious sexual appetite. The escalating hormones lead him to 12-hour sexual encounters and mating sprees that span up to four days (all without stopping to eat, drink or rest with his partner). Many might find his behaviour exciting or unusual, but the antechinus mouse is not the only animal that bases its entire relationship on sex.

Sometimes we find ourselves dating a person right out of our dreams, only to realise that the dream is just a sexual fantasy. The moments you spend together are brief at best, but the sex is incredible and so you keep on telling yourself that this is only temporary. Eventually, all the romps in the leaves result in a desire for a serious relationship. Sooner or later, you may even find yourself falling in love.

Your closest friends point out all the symptoms: a dinner cut short, a late-night call to come over, a general lack of interest in how you are doing, but you have moved far beyond rationality and are determined to parlay this into something substantial. As you try to stimulate interest with light conversation, you start to notice that the only part of you stimulated is your anatomy. At a certain point, it feels like all this "love-making" has little to do with love at all.

For the male antechinus mouse, a long stretch of sex and little rest demands a great deal of strength – strength he does not have. With each sexual escapade he becomes weaker and feebler. Finally he falls to the forest floor; his immune system is worn and his body has broken down. After four long days of erotic activity, he has, literally, screwed himself to death.

The fatalities of countless male antechinus mice actually serve a unique purpose. By forfeiting their lives, the males ensure that their offspring will not have to compete with them for food or territory. Humans are not required to make this sexual sacrifice, yet many of us pursue affairs that are just as destructive. Perhaps for some, focusing on love rather than lovemaking could yield better relationships than that of the tragically oversexed antechinus.