London, Oct 21 Previous studies have shown that the female redback who is roughly twice the size of her male counterpart, regularly eats a number of her male courtiers, although exactly what determines who gets eaten has not been clear.

Now, a new research suggests that it depends on whether the female has been satisfied by the duration of the stimulatory courtship, which entails the male vibrating the female's web for approximately 100 minutes.

The study showed that once the threshold has been reached, a female is unlikely to eat the male upon copulation.

She is also unlikely to eat other males who attempt to mate with her, whether or not they were involved in the courtship.

Researchers Jeffrey Stoltz and Maydianne Andrade, from University of Toronto Scarborough in Ontario, Canada, point out that it means that weaker - and perhaps smarter - males can exploit the courtship work of their rivals.

However, in the end, they say the best odds for a redback male to mate successfully and avoid being eaten afterwards are when he has the female all to himself and can perform the vibrating courtship at length and uninterrupted.

"It's a very sneaky tactic that males are employing here to get around having to expend any energy in courting these females. Females are unable or unwilling to discriminate the source of the courtship, and that provides the opportunity for other males to circumvent female choice," Nature quoted Stoltz a saying.

The work was done using the Australian redback spider (Latrodectus hasselti), a member of the black widow family.

The study has been reported in the journal Proceedings of the Royal Society B. (ANI)