There are spider webs in the highland rainforest of Madagascar that are so huge, they make you wonder if the creatures that built them are big enough to have a starring role in a horror movie.
‘They are no bigger than some of the spiders you can find in gardens in America or Europe,’ said Dr Ingi Agnarsson, a biologist. He and his research partner, Dr Matjaz Kuntner, believe the webs are made by several closely related spider species. All these species are smaller than the thumb of an adult human being.
These are orb spiders, which make large, round webs that look a lot like the ones people decorate with at Halloween. First, the spider will spin a silk thread between two objects, like tree branches. This is called a bridge line.
These spiders, all of which are in the genus Caerostris, have not yet been fully studied by scientists and exist only on the island of Madagascar. Dr Kuntner and Dr Agnarsson plan to travel there in February to study them extensively.
The two facts are probably related, Dr Kuntner said. Web-building spiders tend to use a lot of energy to make their webs, and orb spiders have to make bigger webs than most. The silk would have to be strong to hold up for long enough for the spider to catch food.
‘We have no idea how they make these webs,’ said Dr Kuntner. ‘How might they get those silk threads across the river? Do they send out a thread to float across the river and entangle in a tree on the other side? Probably not,’ said Dr Agnarsson. ‘The distance is too far, and it is likely that the thread would break and fall into the river.’
One of the big questions the scientists want to answer is if the spiders’ prey is as extraordinary in size as their webs are. It seems reasonable to wonder if a big web is meant to catch a big dinner. If it is, what do they do with it once it is caught?
They are both arachnologists, and professors of Arachnology, which is the scientific study of spiders and related animals such as scorpions, pseudoscorpions, and harvestmen, collectively called arachnids.