If male nursery web spiders hope to win the affection of a female mate – and avoid getting eaten alive – they’d better show up with a decent gift.

It’s long been known that nursery web spiders use dead insects as ‘nuptial gifts’ to court their mates, and according to new research, this may work as a shield against sexual cannibalism.

In a recent study, researchers in Denmark found that males who didn’t present their potential mates with a gift were more likely to end up eaten, while those who did were allowed more time for sex.

Typically, the nuptial gifts of male nursery web spiders are the silk-wrapped carcasses of their prey. In a recent study, researchers in Denmark found that males who didn’t present their potential mates with a gift were more likely to end up eaten. Pictured above, a nursery web spider eats a fly

SEXUAL COMPETITION IN SPIDERS Male spiders have developed a number of tactics to ensure successful fertilization of a female, and secure paternity. Recently, researchers found that Madagascan Darwin’s bark spiders engage in 'cunnilingus-like' behaviour with females, and say it may work to signal the male's quality or reduce sperm competition. Other techniques are far more gruesome. Some have been known to guard the female after copulation, or manipulate her appeal through chemical substances. They've even been observed using a 'mating plug' to block the reproductive opening. And recently, researchers discovered another, more effective strategy. Some types of orb-weaving spider have been observed to mutilate the genitalia of females after sex. Mutilation thus establishes monandry, in which the female has just one mating partner during the reproductive period. Advertisement

Typically, the nuptial gifts of male nursery web spiders are the silk-wrapped carcasses of their prey.

Earlier research that attempted to make sense of this practice dismissed it as having ‘no importance,’ but new examinations say these gruesome offerings could be actually be the difference between life and death.

In the study, published today in the journal Biology Letters, researchers from Aarhus University in Denmark found that the presents given to female nursery web spiders by the males that court them might be a precautionary tactic.

While sexual cannibalism runs rampant in the spider community, nursery web spiders (Pisaura mirabilis) are among the few spider species who are known to give nuptial gifts.

And, similar behaviour is seen throughout the animal kingdom.

The team analysed the mating rituals of more than 280 pairs of spiders, the LA Times reports.

Males who showed up empty-handed when paired with a female were cannibalized 15 percent of the time, the researchers found.

For those bringing a nuptial gift, the chance of cannibalization was reduced to just 3.6 percent.

‘The results showed that pre-copulatory sexual cannibalism was enhanced when males courted without a gift and this was independent of female hunger,’ the authors wrote.

‘We propose that the nuptial gift trait has evolved partly as a counter adaptation to female aggression in this spider species.’

Earlier research that attempted to make sense of this practice dismissed it as having ‘no importance,’ but new examinations say these gruesome offerings could be actually be the difference between life and death. In the study, researchers found this may be a precautionary tactic

While sexual cannibalism runs rampant in the spider community, nursery web spiders (Pisaura mirabilis) are among the few spider species who are known to give nuptial gifts. And, similar behaviour is seen throughout the animal kingdom. A nursery web spider is pictured above, on a web

Offering a gift may be an attempt to reduce the risk of getting eaten, the team explained, even if females largely aren’t aggressive.

Most of the time, females weren’t aggressive even to the males who didn’t have gifts, according to LA Times, even after they had been starved for two weeks.

Aside from potential protection against being eaten, the nuptial gifts may have another purpose – longer copulation time.

‘The gift increases the chance that [he] gets to mate in the first place, and increases the duration of the mating, and the amount of sperm he transfers to the female,’ Søren​ Toft, an entomologist at Aarhus University, who led the study, told LA Times.

As female spiders mate with multiple partners, the spider who gets to spend the most time mating is more likely to secure paternity.