Sex is of universal interest. A recent survey of what viewers like top see in wildlife programmes revealed that sex beats death.

Scenes of big predators killing for a living were generally disliked whereas those of animals engaged in breeding were widely relished - especially by women in southern England.

There is no more important story than this. Without sex, life would never have emerged from the primeval sludge of our planet.

'Scenes of animals breeding were relished in southern England.'

For years, I harboured the idea of making this series because there is a widespread misconception in the romantic outcome of love which leads males and females to co-operate to rear their families.

Yet modern research leads to the conclusion that sex really is divisive across the whole of the animal kingdom, turning the relationship between the genders into one that is rife with tension.

So apart from donating eggs and sperm to their joint enterprise, the sexes agree on very little from the moment they meet to the time their offspring leave home.

Cut-throat rivalry, sneaky affairs and reluctant parenting, even occasional infanticide and rebellious daughters are aspects of the 'battle'. These are but some of the amazing strategies illustrated in the series.

Bull elephant seals: The team travelled to 30 counties

And there is much more - such as transvestite male fish, pregnant virgin lizards, lover spiders who commit suicide and female hyenas with male-like sex organs.

Some butterflies employ chastity belts, reef fish undergo rapid sex changes, snakes sport bizarre penises and a few insects apply anti-aphrodisiacs in the utterly selfish pursuit of sexual supremacy.

Weirdest of all are perhaps deep sea angler fish in which each male is a miniature wimp - reduced to a sac of testes and joined to the relatively huge body of his mate - and under her control.

Filmed in 30 countries by an international team of cameramen who had occasionally to endure great hardship. For instance, one had to strap himself high up in a tree for hours at a time in Costa Rica to film red-capped manakins displaying.

Another had to capture damsel fly mating while crouched in a fast-flowing river in France.

Arduous expeditions were made to remote regions of both Lake Malawi and to the mountains of central Ethiopia. In Papua New Guinea, ex-'head-hunters' were enlisted to erect lofty tree platforms to film the ultimate of sexual dandies.