Spiders are among the many creatures that people are afraid of. Even though they are small, these hairy-legged multiple-eyed creatures constitute one of the major predatory species on our planet, and they don’t even have to hunt. They have the perfect mechanism to catch their prey in the form of the webs they weave. Once their web is in place, the prey comes to them and gets trapped, and they don’t have to move a single muscle. Being larger in size compared to spiders, none of us have probably ever worried about being eaten by them. But two European biologists wondered what would happen if spiders ate humans and here is what they’ve found.
According to biologists Martin Nyffeler and Klaus Birkhofer, the entire spider population on Earth consumes about 400 to 800 million tons of prey per year, while the spiders themselves weigh about 25 million tons.
Spiders are found everywhere. No matter what corner of the world you are in, they are in your bedroom, in your bathroom, in the kitchen, in the garden, and many times more in number than that in the forests and other areas uninhabited by humans. According to a survey, spiders are found in one hundred percent of the homes in North Carolina, sixty-eight percent of the bathrooms and seventy-five percent of bedrooms. If you want an analogy to more easily visualize, the Titanic weighed about 52,000 tons. That would mean it would take 478 Titanic‘s to weigh the same as all the spiders in the world.
The population density of spiders is 131 spiders per square meter and can go as high as 1,000 per square meter in favorable conditions.
There are over 45,700 different species of spiders and, with the exception of Antarctica and bodies of water, they are found literally everywhere on land. In fact, they could also be found in deserts and the tundras. While it is estimated that the global average density is 131 spiders per square meter, under certain favorable conditions 1,000 or more spiders have been observed per square meter.
Spiders can eat about ten percent of their body weight every day. That means it takes 2,000 pounds of spiders to eat a 200-pound person.
There are over seven billion people in the world who consume millions of tons of food every day. In 2005, according to a study, the global adult human biomass was approximately 287 million tons, that means 260 billion kg or 574 billion pounds.
So, to put things in perspective, 287 million tons of adult humans would actually leave at least half the spider population hungry by the end of a year!
Well, you could try to be generous by adding the biomass of children as well which would be around another 70 million tons. That would still fall short of the 400 to 800 million tons of annual intake of the world’s spider population. Perhaps we should consider ourselves lucky that spiders are happy with the various bugs and pests that nature has provided them as prey!
[sources: NationalPost, Wikipedia]