"Trash boy" spider lures females with fake gifts to mate; understand

Males of the Pisaura mirabilis spider use gifts in the form of food, with no nutritional value, to attract females and ensure mating. According to a study published in the scientific journal Ethology, this "deception" tactic consists of wrapping remains of prey or fragments of vegetation in silk to simulate valuable food.

Research indicates that the likelihood of a male adopting this strategy is linked to personality traits, such as aggressiveness, and his body size.

Reproduction and deception strategies
In nature, males of this species often offer fresh prey wrapped in silk as an investment to prolong copulation time and increase fertilization success.

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However, the production of these gifts generates costs, such as energy spent hunting and the loss of the meal itself.

To reduce these costs, some individuals use alternative reproduction tactics, offering "useless gifts".

Although this deception may result in shorter copulations, it allows the male to mate without having to invest real nutritional resources, maintaining mating success similar to that of males offering legitimate prey.

Influence of personality and size
The experimental study evaluated how individual behavior influences the choice for valueless items.

Researchers found that larger males with higher levels of aggression were significantly more likely to accept and handle dehydrated prey carcasses.

The analysis shows that more aggressive individuals tend to respond more intensely to external stimuli, which makes them more likely to collect available items in environments with scarcity of resources.

Interestingly, although environmental exploration is a consistent personality trait in these spiders, it has not shown a direct correlation with the production of fake gifts.

Maintenance of the tactic in the population
The existence of these different strategies suggests that deception is an effective way of ensuring reproduction under varying environmental conditions, such as low food availability.

The research reinforces that individual variation in the behavior and physical state of males helps explain how tactics with different biological returns coexist in the same population.

Understanding these nuances in animal behavior contributes to the advancement of theories on the evolution of mating strategies and sexual selection in invertebrates.

Source: CNN