How Many Spiders Are Left in the World?
WouterA new study estimates that spiders eat about 400 to 800 million tons of prey each year. This would equal the amount of food humans eat annually.
Spiders are one of the largest and most diverse groups of animals on Earth. There are at least 43,000 species, ranging from a tiny moss spider to the endangered Gibraltar funnel-web spider.
In addition to being an arachnologist’s delight, spiders play a vital role in nature conservation. They are a primary source of food for birds and other animals. They also provide a vital service to humans. They kill a wide variety of insects, some of which we would rather not have in our yards.
In addition to feeding on other spiders, the largest species consume birds, small mammals, fish, frogs, and even insects. The biggest predators on Earth, arachnids are capable of hunting in forests, under water, and in litter habitats. They are also affected by habitat loss and invasive species.
A few larger species also feed on other large animals, such as birds and lizards. The venom of some spiders can cause skin lesions in humans.
While not every spider is dangerous, a few are. The Portia spider, for example, has a highly developed tactic selection ability. It uses silk in many ways, including in its webs. Its other responsibilities include caring for its young.
There are no definitive answers to the question of how many spiders are left in the world. It’s hard to estimate their impact, however, as the arachnids live in relative secrecy.
