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Aggressive jumping spiders make faster decisions and remain good at it

   Anne Taylors 기자   2017-08-03 09:50

In the photo: An example specie of a jumping spider / Photo by: Mopsgesicht via Pixabay

A team of scientists from the National University of Singapore (NUS) has taken an extra leap in filling the knowledge gap that exists between humans and spiders by uncovering more facts about the decision-making and hunting styles that spider’s exhibit.

We already know that spiders and humans are very much alike when it comes to personality.But there’s much to learn about this connection, particularly the manner in which the two species think, decide, and act.

What decision-making styles do spiders exhibit?

When humans make decisions in haste, they are bound to make mistakes.Is it the same case for spiders?  The NUS research team used a species of jumping spider scientifically known as Portia labiate to answer this question (precisely because of the species’ high cognitive abilities and complex forage strategies, as well as its unexplored personality).

Led by Associate Professor Li Daiqin, from the NUS Faculty of Science, the research team, studied the aggressiveness of Portia Labiatae spiders by observing how they reacted to being touched with a soft brush.Those that attacked the brush were proven to be aggressive, in contrast to the ones that escaped.

After conducting enough observations on the personalities of the spiders, the study proceeded to examine how they make decisions.

The researchers began by giving the spiders a chance to choose between large prey and small prey.While the large prey was better in quality, it was more likely to attack back.On the other hand, the small prey was lower in quality but easier to attack.

The experiment revealed the time it took for the spiders to make a decision as well as the choices they made.Although aggressive spiders were found to be faster at making decisions than their passive counterparts, the choices the two groups made were similar in accuracy.

The findings and what they mean

In line with the results posted on the scientific journal of Behavioral Ecology, the experiment concluded that the personality of Portia labiate is related to the species’ cognitive style.

“The outcome is rather surprising, as our team had initially thought that spiders that make quick decisions are more likely to make the wrong choices, similar to humans,” Says Associate Professor Li.In addition, he believes that this discovery will give scientists a better insight of ecological processes between predator and prey as well as various hunting styles in the animal kingdom.

How do spiders perform in foraging?

Predators often look at the size, speed, and strength of the prey before proceeding to execute an attack.According to Professor Li’s study, the hunting strategy of a spider is also dependent on its personality, although not to a great degree.

In the study, the researchers scrutinized the personalities and behavioral predictabilities of two species of jumping spiders, namely Portia labiate (the predator) and Cosmophasis umbratica (the prey).The aggressiveness of the predator was measured by placing mirrors at their fronts and recording the spiders’ responses to their images.

Spiders that touched the mirrors were regarded as aggressive while those that didn’t were considered docile.To assess the boldness of the prey toward the predator, the researchers introduced mock predators into the container and recorded the behavior.

More valid results were collected by repeating the procedure five times to estimate the true predictability of behavior, as well as to reveal the connection between the personality and predictability of spiders.

As well, the researchers carried out experiments to study the interaction of predator and prey.They introduced a single predator in the presence of one prey and recorded the foraging performance of the former.Data on different pairings were then collected and analyzed.

Aggressive predators performed well when attacking prey with unpredictable behavior.In contrast, non-aggressive predators performed better at hunting prey with predictable behavior.

Photo by: verena-timtschenko via Pixabay

Conclusion

As opposed to human beings, aggressive jumping spiders make faster decisions without the expense of accuracy.They are therefore faster at making choices and precise in making attacks during foraging.

According to Associate Professor Li, more knowledge on the personalities of spiders will help scientists understand how individual organisms can improve their survival abilities and reproduction.It will also contribute to the comprehension of evolutionary theories and give a better intuition of the human personality and its evolution.

Other areas that the study findings are likely to be of impact involve the linkage between personalities and invasion biology, conservation, and climate change.

The same research team intends to carry out more studies in the near future to assess and learn more about spiders and their personalities.The ones particularly considered by Associate Professor Li are directed toward learning more about the connection between various personality and decision-making styles, in which he intends to give spiders tasks of different levels of difficulty.

Other studies involving the study of gene profiles of spiders are also underway.