Increased food shortage due to growing global population has governments and organizations around the world worried about the coming decades. Considering the amount of food an average person consumes in every year, the only way we can solve this worldwide crisis is by massively bolstering food production. Interestingly, the one organism that eats even more voraciously than man is actually the spider.
According to a new study, these eight-legged arthropods consume between 400 and 800 million tons of food annually, in the form of insects, lizards and at times frogs. In case you are wondering, that’s twice the total weight of all human adults. Given that nearly 45,000 different species of spiders exist in the world today, most of which are nocturnal and therefore elusive, scientists usually have a hard time studying them in their natural habitat.
As part of the new research, a team from Sweden’s Lund University and Switzerland-based University of Basel painstakingly perused existing literature on spiders, using special mathematical models to assess the kind of ecological impact they have. To that end, the researchers undertook two different studies: the first involving the insects’ annual prey kill volume and the second investigating their food requirements in terms of the total spider biomass.
The team’s analysis in turn revealed that the global spider population, weighing somewhere around 25 million tons, is responsible for the consumption of approximately 400 to 800 million tons of prey in a single year. While most spider species feed on tiny insects, larger kinds often eat lizards, frogs, snakes and even small bats. By comparison, humans consume a total of 400 million tons of biomass every year, mostly in the form of meat and fish. Whales, on other hand, wipe out somewhere between 280 to 500 million tons of organisms on a yearly basis.
The research also reveals that spiders are more efficient as predators in certain environments like grasslands and forests than others. Over 95-percent of the spiders’ annual prey kill takes place in these two habitats, compared to the less than two-percent that occurs in croplands. Speaking about the findings, recently published in The Science of Nature journal, Martin Nyffeler, a scientist at the University of Basel and the paper’s chief author, said:
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. Spiders thus make an essential contribution to maintaining the ecological balance of nature.
Source: University of Basel