To date, 52,000 species of spiders have been described. Although it is one of the largest and most diverse groups of animals, it is still relatively poorly understood. At the Faculty of Biology and Environmental Protection of the University of Lodz research on the hunting strategies of jumping spiders is being conducted. – This is the most diverse and interesting family of spiders. They are spiders that actively hunt, which means that they do not build webs, but hunt actively, approaching and jumping on their prey even from a distance of several dozen centimetres – says Prof. Maciej Bartos. – Interestingly, depending on the type of prey, spiders choose different hunting tactics, we are studying the basis for their decisions.
It might seem that there is nothing extraordinary about this, after all, lions are hunted differently than snakes. It is similar with insects; different hunting tactics will work for slow caterpillars and different for fast and agile flies. – It is amazing how these spiders are able to identify different categories of prey, and often from a great distance – says Prof. Bartos. – Jumping spiders are an excellent research model, because the hunting process can be quite long and consists of many stages. Jumping spiders have several features that are hard to find in other species. –First, they have eyes with very high resolution, which allows them to identify very small details – the researcher explains. – Jumping spiders see only slightly worse than humans, but better than cats or most birds. And we're only talking about the main pair of eyes. We have to remember that spiders have four pairs of them, and each has a different function. – It's a very interesting modular system that allows you to have a view close to 3600 and at the same time cope with an excess of information – explains Prof. Bartos. – We have to remember that spiders have small brains (about half a million neurons, or 170 thousand times less than a human). The research conducted in Lodz shows that despite their small brains, these animals are capable of making very complex decisions.
Primates are known to have the ability to create mental maps, which means that if they cannot go directly to a point they can see, they can plan an alternative route and get to it, even if they lose sight of it for a while. This is a very unique ability that only the most highly evolved mammals possess. It turns out that jumping spiders can do it too! They are able to reach their prey even if they have lost sight of it for half an hour
– explains Prof. Maciej Bartos.
In recent years, research in this field has accelerated significantly due to the development of technology. – Using graphic programs, we create animations – we design an object (prey) and its surroundings and display them to a spider on a tiny screen – explains Prof. Maciej Bartos. – By manipulating these objects, we can observe how the spider interpreted the type of prey, what hunting strategy it chose and what factors influenced the decision.
Italian scientists, who the University of Lodz collaborates with, are conducting similar research, but using equipment based on an operation similar to VR goggles. – A spider is placed on a ball suspended in an air stream and various objects are displayed on screens placed around it – the researcher explains. – The movements of the ball and the spider are recorded by a camera that is fast enough and, on this basis, it is possible to observe how the spider reacts to the images displayed to it. This way you can create the illusion of reality. This technology will soon also be used at the University of Lodz.
What is the purpose of studying spiders? – How we humans perceive the world is related to how our ancestors did it. We have common mechanisms for identifying objects – assures Prof. Maciej Bartos. – It is best to study them on simple organisms, such as spiders, especially if we are interested in innate behaviours – not everything can be studied on humans. Thanks to this type of research, we can learn a lot about the mechanisms of action of animals, but also humans.
Interestingly, some of these mechanisms are already used in technology. – It turns out that jumping spiders have such a unique ability to measure distance that this mechanism can be used to create modern cameras – explains Prof. Maciej Bartos. – American scientists who conducted research on spider vision, today work for Apple and participate in the construction of smartphone cameras. By examining the eyesight of spiders, you can literally "look into their eyes" and see what they are looking at, which in turn is a mechanism used in advertising. Research conducted on other groups of animals (for example, mantises) has been used in the design of autonomous vehicles. – Identifying objects in space, which we study by analysing the behaviour of jumping spiders, can be used in many areas of life – concludes Dr hab. Bartos.