Spider webs are not just a means of capture: on some occasions, they can turn into an efficient means of air transport. The ballooning technique (from the English word for ballooning) has been known for a long time. Certain species of spider secrete silk threads that function as sails, thanks to which they are raised and allowed to be transported even at great distances.
Lords of the air. Now some German scientists have studied this original form of dispersion on the territory more closely, discovering that preparations for take-off are accurate and far from random. They placed 14 crab spiders (gen. Xysticus) on a mushroom-shaped platform in Lilienthal Park, the same park in Berlin where aviation pioneer Otto Lilienthal (1848-1896) conducted his personal flight tests with the first gliders.
In a separate experiment, the researchers instead observed the same spiders in a miniature wind tunnel, in which they could measure temperature and air flow velocity. You can see the test footage in this beautiful Science video (the text continues after the movie).
Careful preparation. Spiders did not deploy their sails at random. Before taking flight, they tested wind direction and speed by lifting two legs for 5-8 seconds. On cold and windy days, they sheltered on one side of the platform without taking off. But in the warm ones and with a breeze no faster than 3 meters per second, they raised the abdomen releasing about sixty silk threads, and forming a triangular canvas which they then used to let themselves be lifted by the wind.
The study, in the pre-publication phase, is the first to show that, like any good aviator who respects himself, even spiders taste the weather conditions, before exposing themselves to a risk.