How Much Do Spiders Eat?
WouterSpiders eat just as much as humans, consuming about 400 million tons of food and prey each year. They mostly eat bugs, but there are also a few species that snack on small mammals and birds.
Using published data on the spider biomass in different ecosystems, researchers estimated the total amount of food spiders consume each year. They came up with a figure of between 400 and 800 million tons. This amount is larger than the meat consumption of all adult humans.
This study is important because it was conducted by two European biologists, Martin Nyffeler of the University of Basel in Switzerland and Klaus Birkhofer of Lund University in Sweden. They reviewed 65 previous studies to come up with a final estimate.
The researchers used two methods to determine the amount of food consumed by spiders. One was based on the number of insects they capture during their hunt. The second method used estimates of the spider’s number per square meter. The researchers found that in various biomes, the average density of spiders was around 131 per square meter.
The researchers also looked at the total weight of spiders worldwide. Their estimated figure was around 25 million tonnes. This is about twice as much as the meat and fish that all adult humans eat each year.
The researchers estimate that spiders eat between 300 and 800 million tons of invertebrates and prey each year. This figure is about the same amount as the amount eaten by all whale species.
