Hungry Little Monsters: Spiders Eat More Meat Than Humans Do
Who would have thought that little spiders could be ravenous?
A new study has revealed that spiders eat 400 to 800 million tons of prey every year. That is double the total weight of meat that humans consume each year and exceeds the appetite of larger mammals like whales.
United Nations Food and Agriculture Organisation estimates that humans on Earth consume about 400 million tonnes of meat and fish each year, New Scientist notes.
According to the study published in the journal The Science of Nature, the total amount of food was calculated by calculating the total number of spiders in the world, in terms of biomass and then multiplying it to a spiders' food requirements per unit of body weight. They also took note of the prey census data from previous field studies in their calculations.
As noted by Science Alert, there are about 25 million tonnes of spiders on Earth right now; some of which gather around forests, croplands and grasslands. But the majority, about 95 percent of the annual spider prey kill, live in grasslands.
Spiders primarily feed on insects. According to the researchers, most of the spiders considered in the study prey on insects and springtails (Collembola), while in some cases they feed on frogs, lizards, snakes, fish, birds, bats and plants.
The researchers highlighted while the global population of 25 million tonnes of spiders certainly appears big, spiders are integral part of the ecosystem.
"Our calculations let us quantify for the first time on a global scale that spiders are major natural enemies of insects. In concert with other insectivorous animals such as ants and birds, they help to reduce the population densities of insects significantly," Martin Nyffeler from the University of Basel, lead author of the study said in a press release obtained by Phys.org. "Spiders thus make an essential contribution to maintaining the ecological balance of nature," he added.